Crop-damaging armyworms raise alarm in Asia: FAO

Crop-damaging insects these days sweeping throughout Asia are alarming smallholder farmers as the threaten their livelihoods, the UN food company reported.
At the similar time, the Food and Agriculture Organization (FAO) stated the wear and tear can also be restricted.

Fall Armyworms” (FAW) are native to the America but they have been moving eastwards since 2016, sweeping throughout Africa, the place they led to US$1 billion to US$3 billion in damage, earlier than arriving in Asia.

We need to work together because this is a pest that has no respect for international boundaries, threatens our food security, our economies, domestic and international trade

Kundhavi Kadiresan

The flying bugs arrived in India in July and have since spread to Sri Lanka, Bangladesh, Myanmar, Thailand and China’s Yunnan province, FAO stated.

They feed mostly on maize, for which China is the arena’s second-largest producer, and will feed on several species of vegetation, including rice and sugar cane – two of Thailand’s main commodities.
a 3-day FAO assembly is being held in Bangkok, with officers from affected nations and mavens discussing ways to limit Fall Armyworm infestations amid a “growing sense of alarm”.

“We need to work together because this is a pest that has no respect for international boundaries, threatens our food security, our economies, domestic and international trade,” Kundhavi Kadiresan, the FAO’s assistant director-general and regional consultant for Asia and the Pacific, mentioned in a observation.

“When fall armyworm made landfall in India, its arrival did not come as a complete surprise, we were not caught unaware. And that’s a good start – indeed it was a good head start,” Kadiresan said.

The Plant Protection Commission for Asia and the Pacific started raising consciousness concerning the risk early final yr, sharing key knowledge on the pest, its unfold against Asia, and the best way to manage it sustainably in case of infestation.
Once an infestation is confirmed, governments are beginning efforts to proceed to boost consciousness and monitor the presence and unfold of FAW on maize and different vegetation.

    FAO has been working with the related authorities to initiate awareness programmes that inform and train farmers on built-in pest management techniques. These include identifying herbal enemies of the Fall Armyworm, bettering herbal biological controls and mechanical controls, such as crushing egg lots and employing using biopesticides.

    The use of chemical insecticides needs to be very moderately thought to be, given that FAW larvae disguise largely within the ring of leaves (whorl), and that chemical pesticides may have unwanted effects on the setting and public well being, FAO stated.

    This is taken into consideration at the coverage and box degree. With these measures put in position, the uncomfortable side effects of infestations may also be sustainably controlled and can assist to care for populations low sufficient to limit economic and livelihood harm.

    Pink Bollworm: Biology And Host Preference in Laboratory

    Scientific Name: Pectinophora gossypiella Saunders

    Family: Gelechiidae

    Order:Lepidoptera

    Stages of Pink Bollworm

    Pink bollworm has 4 stages that is egg, larvae, pupa and adult.

    Egg:

    Eggs are elongating and oval having 0.1mm length and 0.5mm width. Newly laid eggs are slightly greenish in colour but at maturity they turned reddish.

    Larvae:

    [woo_product_slider id=”64262″]

    The larvae are white with a dark head at initial stage.  The full-grown larvae are 10 to 12 mm long and are white with a double red band on the upper portion of each segment.

    Pupa:

    The pupa is almost 8 to 10 mm long, reddish brown; posterior end pointed and terminating in a short, no long setae, spines or hooks, except on last joint. At maturity, the pupa becomes much darker; the adult’s eyes can be seen prominently under the gena of the pupal skin, and the segmentation of the adult antennae and legs becomes discernible.

    Dr. Faisal Hafeez, Ayesha Iftikhar, Muhammad Sohaib.

    Ayub Agricultural Research Institute (AARI) Faisalabad.

    Adult:

    They are brown with a wingspan of 15 to 20 mm. 

    The adults are dark-brown moths measuring about 12 to 20 mm across the wings. The head is reddish brown with pale, scales. Antennae are brown and the basal segment bears a pecten of five or six long hair-like scales. The have scaled proboscis.  

    Forewings are elongating and oval, pointed at the tips and bearing a wide fringe. The hind wings are broader than the fore wings, and silvery gray in colour with a darker, iridescent hind margin.

    Host preference of pink bollworm larvae:

    Cotton bolls were collected from cotton sticks placed at field area of Entomological Research Institute, (AARI) Faisalabad. Cotton bolls were brought into Biological Control Laboratory. The larvae were separated from cotton bolls into a petri dish (6cm×0.5 inches). Further these larvae were used to check the host preference. The environmental conditions were 25 ± 30 % RH and 55 ± 65 ®C Temperature.

    Three Choice Bioassay:

    A glass petri dish (15 cm× 2.5 cm) was used having weight of 218.39 grams. Three hosts including okra, Abelmoschusesculentus, cotton, Gossypiumhirsutumand tomato, Solanum lycopersicum after weighing themthose were placed in petri dish at different positions. okra (3 g), cotton (2.53 g), tomato (5.81g). It was observed that larvae moved towards cotton boll after 6 minutes and started feeding.However, it reached on okra after 10 minutes. This showed that larvae preferred cotton as compared to other hosts.

    Two Choice Bioassay:

     In the presence of okra and tomato, it preferred okra but didn’t feed as good as on cotton. Similarly, in case of cotton +tomato and okra +tomato, it preferred cotton and tomato respectively.

    Free Choice Bioassay:

    In free choice assay, above three hosts were placed in separate petri dishes and larvae was released at centre and stop watch was on. It was observed that towards cotton boll larvae moved within 4 minutes and start feeding, while it moved towards okra after 8 minutes and didn’t feed well and it reached on tomato almost after 15 minutesbut didn’t feed at all.

    Pakistan warned against deadly wheat pest

    The Internati­onal Maize and Wheat Impro­vement Centre (CIMMYT) has cautioned Pakistan to take steps to offer protection to its plants from the ‘fall armyworm’ (FAW), a devastating pest that has been identified for the first time on the Indian subcontinent.

    [woo_product_slider id=”64262″]

    Director-General, CIMMYT, Dr Martin Kropff, now visiting Pakistan, held a meeting with Minister for National Food Security and Research Sahibzada Mehboob Sultan on Thursday and offered cooperation of the Mexico-based organisation in tackling the prevalent risk of FAW in Pakistan.

    “We want that our future cooperation in this regard must continue, and Pakistan may not only ensure a prompt surveillance system but also bring more disease-resistant varieties of wheat and maize,” Dr Martin said.

    Native to the Americas, the pest is understood to eat over 80 plant species, with a specific preference for maize, a prime staple crop world wide.

    The fall armyworm was once first officially reported in Nigeria in West Africa in 2016, and rapidly unfold throughout 44 nations in sub-Saharan Africa. Sightings of damage to maize plants in India because of ‘fall armyworm’ mark the primary record of the pest in Asia.

    The pest has the possible to unfold briefly no longer best within India, but in addition to different neighbouring countries in Asia, owing to appropriate climatic stipulations, in line with a pest alert revealed by means of the National Bureau of Agricultural Research, a part of the Indian Council of Agricultural Research.

    Dr Martin stated that CIMMYT is amazed at the remarkable luck of wheat programme in Pakistan. Director CIMMYT’s Global Wheat Programme, Hans Braun emphasised the need to be cognisant of securing the centered yield in wheat as the global local weather trade may pose a really perfect challenge and one Celsius drop in temperature all over the evening time would possibly lower seven according to cent of wheat yield, hence with aggregate of clever interventions and good subsidies, huge ends up in meals safety could be achieved.
    Mr Mehboob Sultan appreciated the contributions of CIMMYT in Pakistan since the green revolution and stated that the existing government used to be bold for the revival of agriculture and breakthrough in agro-research.

    Bio-intensive integrated management of jassid, amrasca biguttula biguttula (ishida) on bt-cotton in punjab, pakistan

    The studies were conducted on bio-intensive management of Jassid, Amrasca biguttula biguttula (Ishida) on various genotypes of Bt-cotton. Experiments were conducted in farmer’s field and laboratories of the Agricultural Entomology Department, University of Agriculture, Faisalabad from 2009 to 2011. The objectives of these studies were to control the pest by bio-intensive management methods and find an effective, safe and economical method/s for recommendation to the farmers. A Field experiment was carried to determine resistance or susceptibility of twenty genotypes of Bt-cotton against Jassid (nymph + adult) based on per seedling and per leaf population density count during 2009 and 2010 under field conditions.

    [woo_product_slider id=”64262″]

    Laboratory experiments were carried out to study Physico-morphological and chemical plant characteristics with the objective to determine their effects on the population of Jassid. The results revealed that during preliminary field trials, the genotype Auriga-213 showed maximum Jassid populations, whereas the genotype IR-824 had zero population per seedling. Auriga-101 and MNH-886 possessed maximum Jassid populations per leaf (susceptible) whereas MG-06 showed minimum (comparatively resistant). During a final screening trial, the genotypes Auriga-101 and MNH-886 proved to be susceptible, AA-703 and MG-06 appeared as comparatively resistant, while BT-121 and CA-12 were intermediate based on both per seedlings and per leaf population density counts of Jassids. The maximum population of Jassid (nymph + adult) per leaf was recorded on August 01, 2009 and August 16, 2010. There was only one peak in both the study years. The HPSIs (Host Plant Susceptibility Indices) on an average basis during both years showed that Auriga-101 and MNH-886 were susceptible, whereas AA-703 and MG-06 showed minimum HPSI and proved comparatively resistant, based per seedling and per population density counts of Jassid per leaf. The results revealed that minimum temperature during 2009 exerted a positive and significant (P < 0.01) correlation with the Jassid population with a r-value of 0.667 while during 2010 maximum temperature had negative and significant correlation (P < 0.01) with the pest density on per leaf basis with a r-value of 0.558. Relative humidity and rainfall during 2010 and on cumulative basis of both the study years 2009 and 2010 resulted in a significant (P < 0.01) and positive correlation with the pest population. Multiple regression models reveal that minimum temperature during 2009 and 2010 and on cumulative basis of both the study years resulted in maximum impact, while maximum temperature during 2010 also exerted a reasonable contribution to the pest population. The results revealed that hair density on the plant’s midrib, vein and lamina had a negative and significant correlation, length of hair on midrib and vein had a non significant correlation while thickness of leaf lamina had a positive and significant correlation with the Jassid population per leaf. Gossypol glands on midrib and vein showed positive and significant correlation, while on lamina they had a negative and significant effect. Total minerals exerted positive and significant effect, whereas reduced sugar, calcium and manganese showed negative and significant correlation with Jassid density. Multiple linear regression models revealed that hair density on midrib and total minerals in the leaves were the most important characters. The minimum Jassid population was recorded to be 0.35 per leaf with maximum mortality of pest i.e. 88.59 % where all control methods were integrated together. The maximum population was recorded to be 2.22/leaf in those plots where Coccinella septumpunctata was released. The application of Spinosad 240 SC applied 18 singly and integrated with other control methods resulted in higher pest mortality. The results pertaining to seed cotton yield in kg/plot showed a significant difference among various control treatments. The maximum yield was recorded in those plots where all the control methods were integrated whereas yield was minimum where C. carnea was released. The maximum cost benefit ratio was calculated where Spinosad 240 SC was sprayed. The integration of all the control methods resulted in low CBR (Cost Benefit Ratio) due to increase in expenditure.

    Laboratory experiments were carried out to study Physico-morphological and chemical plant characteristics with the objective to determine their effects on the population of Jassid. The results revealed that during preliminary field trials, the genotype Auriga-213 showed maximum Jassid populations, whereas the genotype IR-824 had zero population per seedling. Auriga-101 and MNH-886 possessed maximum Jassid populations per leaf (susceptible) whereas MG-06 showed minimum (comparatively resistant). During a final screening trial, the genotypes Auriga-101 and MNH-886 proved to be susceptible, AA-703 and MG-06 appeared as comparatively resistant, while BT-121 and CA-12 were intermediate based on both per seedlings and per leaf population density counts of Jassids. The maximum population of Jassid (nymph + adult) per leaf was recorded on August 01, 2009 and August 16, 2010. There was only one peak in both the study years. The HPSIs (Host Plant Susceptibility Indices) on an average basis during both years showed that Auriga-101 and MNH-886 were susceptible, whereas AA-703 and MG-06 showed minimum HPSI and proved comparatively resistant, based per seedling and per population density counts of Jassid per leaf. The results revealed that minimum temperature during 2009 exerted a positive and significant (P < 0.01) correlation with the Jassid population with a r-value of 0.667 while during 2010 maximum temperature had negative and significant correlation (P < 0.01) with the pest density on per leaf basis with a r-value of 0.558. Relative humidity and rainfall during 2010 and on cumulative basis of both the study years 2009 and 2010 resulted in a significant (P < 0.01) and positive correlation with the pest population. Multiple regression models reveal that minimum temperature during 2009 and 2010 and on cumulative basis of both the study years resulted in maximum impact, while maximum temperature during 2010 also exerted a reasonable contribution to the pest population. The results revealed that hair density on the plant’s midrib, vein and lamina had a negative and significant correlation, length of hair on midrib and vein had a non significant correlation while thickness of leaf lamina had a positive and significant correlation with the Jassid population per leaf. Gossypol glands on midrib and vein showed positive and significant correlation, while on lamina they had a negative and significant effect. Total minerals exerted positive and significant effect, whereas reduced sugar, calcium and manganese showed negative and significant correlation with Jassid density. Multiple linear regression models revealed that hair density on midrib and total minerals in the leaves were the most important characters. The minimum Jassid population was recorded to be 0.35 per leaf with maximum mortality of pest i.e. 88.59 % where all control methods were integrated together. The maximum population was recorded to be 2.22/leaf in those plots where Coccinella septumpunctata was released. The application of Spinosad 240 SC applied 18 singly and integrated with other control methods resulted in higher pest mortality. The results pertaining to seed cotton yield in kg/plot showed a significant difference among various control treatments. The maximum yield was recorded in those plots where all the control methods were integrated whereas yield was minimum where C. carnea was released. The maximum cost benefit ratio was calculated where Spinosad 240 SC was sprayed. The integration of all the control methods resulted in low CBR (Cost Benefit Ratio) due to increase in expenditure.

    A Field experiment was carried to determine resistance or susceptibility of twenty genotypes of Bt-cotton against Jassid (nymph + adult) based on per seedling and per leaf population density count during 2009 and 2010 under field conditions. Laboratory experiments were carried out to study Physico-morphological and chemical plant characteristics with the objective to determine their effects on the population of Jassid. The results revealed that during preliminary field trials, the genotype Auriga-213 showed maximum Jassid populations, whereas the genotype IR-824 had zero population per seedling. Auriga-101 and MNH-886 possessed maximum Jassid populations per leaf (susceptible) whereas MG-06 showed minimum (comparatively resistant). During a final screening trial, the genotypes Auriga-101 and MNH-886 proved to be susceptible, AA-703 and MG-06 appeared as comparatively resistant, while BT-121 and CA-12 were intermediate based on both per seedlings and per leaf population density counts of Jassids. The maximum population of Jassid (nymph + adult) per leaf was recorded on August 01, 2009 and August 16, 2010. There was only one peak in both the study years. The HPSIs (Host Plant Susceptibility Indices) on an average basis during both years showed that Auriga-101 and MNH-886 were susceptible, whereas AA-703 and MG-06 showed minimum HPSI and proved comparatively resistant, based per seedling and per population density counts of Jassid per leaf. The results revealed that minimum temperature during 2009 exerted a positive and significant (P < 0.01) correlation with the Jassid population with a r-value of 0.667 while during 2010 maximum temperature had negative and significant correlation (P < 0.01) with the pest density on per leaf basis with a r-value of 0.558. Relative humidity and rainfall during 2010 and on cumulative basis of both the study years 2009 and 2010 resulted in a significant (P < 0.01) and positive correlation with the pest population. Multiple regression models reveal that minimum temperature during 2009 and 2010 and on cumulative basis of both the study years resulted in maximum impact, while maximum temperature during 2010 also exerted a reasonable contribution to the pest population. The results revealed that hair density on the plant’s midrib, vein and lamina had a negative and significant correlation, length of hair on midrib and vein had a non significant correlation while thickness of leaf lamina had a positive and significant correlation with the Jassid population per leaf. Gossypol glands on midrib and vein showed positive and significant correlation, while on lamina they had a negative and significant effect. Total minerals exerted positive and significant effect, whereas reduced sugar, calcium and manganese showed negative and significant correlation with Jassid density. Multiple linear regression models revealed that hair density on midrib and total minerals in the leaves were the most important characters. The minimum Jassid population was recorded to be 0.35 per leaf with maximum mortality of pest i.e. 88.59 % where all control methods were integrated together. The maximum population was recorded to be 2.22/leaf in those plots where Coccinella septumpunctata was released. The application of Spinosad 240 SC applied 18 singly and integrated with other control methods resulted in higher pest mortality. The results pertaining to seed cotton yield in kg/plot showed a significant difference among various control treatments. The maximum yield was recorded in those plots where all the control methods were integrated whereas yield was minimum where C. carnea was released. The maximum cost benefit ratio was calculated where Spinosad 240 SC was sprayed. The integration of all the control methods resulted in low CBR (Cost Benefit Ratio) due to increase in expenditure.

    Author: AKHTAR BHATTI, JAVED

    Full Thesis Click Here

    Green Lace Wing (Chrysoperla carnea) ; A Biological Control Agent

    Kingdom: Animalia
    Phylum: Arthropoda
    Class: Insecta
    Order: Neuroptera
    Family: Chrysopidae
    Subfamily: Chrysopinae
    Genus: Chrysoperla
    Distribution and Habitat
    C. carnea is considered a single Holarctic species scattered across North America, Europe, North Africa and Asia. This species is usually found in herbaceous vegetation in open fields during summer and in urban areas in fall and spring.
    [woo_product_slider id=”64262″]
    Morphology
    Adult green lacewings are a pale green colour with long, threadlike antennae and glossy, golden, compound eyes. They have a delicate appearance and are from twelve to twenty millimetres long with large, membranous, pale green wings. Larvea are brown and are about one millimetre long when they first hatch. The larvae grow to about eight millimetres long before they spin circular cocoons and pupate. Eggs are oval and secured to the plant by long slender stalks. They are pale green when first laid but become gray later. The lower growth threshold of C. carnea is about 10 ˚C.
    Life Cycle
    The Chrysopa adults overwinter covered in leaf litter at the edge of fields or other bumpy places, emerging when the weather warms up in spring. Each female lacewing lays several hundred small eggs at the rate of two to five per day, choosing obscured spots underneath leaves or on shoots near latent prey. The eggs are normally laid during the hours of darkness.
    The larvae hatch in three to six days, eat avidly and moult three times as they grow. They feed not only on aphids but also on many other types of insects and even prey on larger creatures, such as caterpillars. When food is limited they turn cannibal and eat each other. After two to three weeks, the mature larvae secrete silk and build round, parchment-like cocoons in cloaked positions on plants. The development of the cocoon usually lasts for one or two weeks and depends on several factors, mainly temperature and sex. For example, cocoon development is completed in 7.1 days at 24°C and in 12.7 days at 20°C
    From these, the adults emerge ten to fourteen days later. The length of the life cycle (under 4 weeks in summer conditions) is greatly inclined by the temperature and there may be several generations each year under positive conditions.
    Uses
    ⦁ Classical biological control, by introduction of a new natural enemy
    ⦁ amplification by means of inoculative releases
    ⦁ intensification by means of inundative releases
    ⦁ Conservation
    ⦁ Effective biological control agent
    Chrysoperla as biological control agent:
    mass-rearing chrysoperla for use in biological
    The mass-rearing of commercially available chrysoperla is mainly based on eggs of lepidopteran specie genera Sitotroga, Ephestia (Anagasta) and Corcyra that have been proved as nutritionally better and of low cost food to produce, in comparison to other artificial diets tested. For suppressing sucking pests, egg cards of C. carnea are used in different numbers like 50 cards for Sugarcane and vegetables and 25 for cotton. One card contains 20-25 eggs of C.carnea. Rearing of C. carnea in the glass cages proved superior than other types of cages, requiring minimum time from the point of sanitation, food provision, egg harvesting and handling of adults. This will save labour costs and will be more economical than other types of cages for mass production unit in an insectary.
    For C.carnea is ideal temperature is 22-27 degree Celsius. At high temperature insect become fidgety. Food is provided in 1:1:1 Yeast, Honey and mineral water with the help of moving plastic bars. Freshly laid eggs of S. cerealella after weighing to a specific quantity, placed in each vial larval diet. S. cereallela eggs are suggested as more competent and economic host as compared to P. solenopsis crawlers. Its life cycle is about 19-31 days. The green lacewing adults emerge from litter when the weather becomes warm during spring season. Female lays several hundred eggs with the ratio of two to five per day.
    Eggs are normally laid during the darkness. The larvae hatch in three to six days. Then larvae secrete silk type fabric and form cocoons. Adults emerge 10 to 14 days later. Eggs are harvested from consumable black muslin cloth cover with the help of sharp razor blade. Eggs laid on other structures within cage such as cage walls, water containing vials etc. After collecting eggs on cards, the cards are supplied to the farmers.
    Risks
    ⦁ The possibility of global or local extinction of a native species;
    ⦁ Large reductions in either the distribution or abundance of native organisms;
    ⦁ Interference in the efficacy of native natural enemies of pests via interactions or competitive displacement;
    ⦁ Vectoring of pathogens harmful to native organisms
    ⦁ Loss of biodiversity and identity of native
    ⦁ Species via hybridization between close relatives
    ⦁ Disperse and leave the target field before ovipositing
    Characteristics
    Larval characteristics:
    ⦁ Resistance to insecticides
    ⦁ Short developmental times:
    ⦁ Predation efficiency:
    ⦁ Low dispersal ability
    ⦁ Broad prey range
    ⦁ Effective biological control agents
    Adult characteristics:
    ⦁ Easy mass – rearing
    ⦁ High reproductive potential
    ⦁ Attractions to protein hydrolysates
    Shoaib Naeem, Jahangir Ahmad, Muhammad Asad, Muhammad Muddassir
    University of Agriculture Faisalabad, Pakistan.

    Common Pests and Disease

    Pests and Disease


    Aphids
    These are small brown colored insects. They suck the sap from the leaves and branches and cause great damage to trees and reduction of yield. Aphid attack is severe during Feb and April. Use Dizenon 40% or Eldrine 20%, 1 kg in 450 litres of water. Insecticides should not be applied within 6 weeks of marketing the fruit.

    Citrus Leaf Minor:
    This attacks the leaves. the attacked leaves become curled and deformed. If causes great losses in growth and yield. Use Malathion 57 or Matasystox 50% at the rate of 500 grams in 450 litres of water per acre for its control.

    Lemon Butterfly
    This also attacks fresh leaves. It can be controlled effectively by using Malathion and Metasystox.

    Citrus Whitefly:
    This attacks the fruits and causes great losses in yield and quality. This pest can also be controlled by using Malathion 57%. This should not be applied within 6 weeks of marketing the fruit.

    Red Scales:
    These are sucking types of insects and cause great damage to Kinnow and sweet oranges in Punjab. They can survive throughout the year. Use Parathion or Malathion at the rate of 752 grams in 450 litres of water per acre for its effective control.

    Root Rot:
    This is a fungus which attacks the root of the trees. Its attack is severe in poorly drained soils. The affected tree gradually dries up. Remove the soil from around the affected trees without damaging the roots and improve on farm drainage for its effective control.

    Withertip:
    This disease is caused by nutritional deficiencies. The branches and fruits of the affected trees start drying and the tree becomes uneconomical to maintain. Apply a balanced dose of Bordeaux Mixture 450 after cutting affected branches from the trees.

    Citrus Canker:
    This is a bacterial disease. It attacks leads and the fruits. It forms canker like spots on the leaves and stems of the fruit causing great reduction in yield and quality of the fruit. There is no effective treatment for this disease except to cut and remove the affected trees and spray Formaldehyde at the spots from where the diseased trees have been removed.

    Harvesting:
    Picking of citrus fruits is done almost throughout the year. The fruit should be picked when it is fully ripe. It will not develop taste or sugar in storage after picking. The best method is to pick the individual fruit by holding it in one hand and cutting the stalk with a knife and collecting it into boxes or baskets to avoid injury to the stem. The average yield expected from different types of fruits in various species are 500 to 1000 fruit per tree.

    Pakistan is blessed with a climate ideally suited to the farming of all kinds of fruits – rich in taste and juicy. Farmers have been developing new varieties of fruit by grafting one exotic variety with other.

    Season of Kino in Pakistan starts from December and last till April. Kinnow is very delicious in taste and if treated with proper fungicide and wax and careful handing and storage of Kinnow at about 4 Degree Centigrade can retain it’s freshness until 2 months.

    Pakistan is one of the few countries in the world where some of the varieties of fruits grown in cool temperate climate such as apples, pears, plums and cherries while in warm temperate climate such as apricots, grapes, pomegranates and melon and in tropical and subtropical climate such as bananas, mangoes, dates, guava and citrus so the fruits are usually available throughout the year.

    Nature has blessed Pakistan with ideal climate for growing a wide range of delicious fruits and large varieties of vegetables. Over the years, Pakistani experts have developed unique stains of exotic fruit varieties unmatched for their rich flavor and taste. From the selection of the finest fruits grown, a reasonable quantity is processed and properly packed for sales and consumption in local market and exporting abroad.

    Pakistan exported 268,741 tones of fruits worth US$ 79.83 million during 2000-01, while the export of vegetables stood at $22.50 million. Out of the total exports of fruits and vegetables the share of mangoes was 53,443 tonnes valuing $16.54 million, showing an increase of 43 per cent over the 1999-00.

    Agriculture is the main contributor to GDP either directly or indirectly in the form of agro-based industries. The production of fruits and vegetables is not fully utilized and after their domestic consumption a major part is wasted due to lack of infrastructure, storage and processing facilities. The wastage quantity can be utilized by just streamlining and regulating the system from grower to export markets.

    Pakistan produces large varieties of mangoes, its production has increased from 908 thousand tonnes in 1995-96 to 937 thousand tonnes in 1999-00. World production of mangoes stood at 19 million tons in 1995, which rose to 23.8 million tonnes in 1999, registering an increase of 24.75 per cent over the five years. Philippines and China have achieved much over 100 per cent increase in mango production during that period. Thailand is another country, which has also registered a significant increase. Rise in Pakistan’s annual mango production during 1995-99 is only 3.4 per cent. Our share in global mango production in 1999 is 3.8 per cent.

    Beside mangoes, Pakistani kinoos and apples are also in great demand in the international market. Balochistan produces about 480,000 tones of apples annually but only 3,000 tones were exported last year. About 30 per cent apples wasted every year in Balochistan only. Recently the government has given approval for the establishment of treatment plant in Quetta. While two plants are about to start working in Karachi. It is estimated that after starting of these treatment plants export of apples would be increased to about 20,000 tons per annum. There are good investment opportunities for the private sector to establish processing units near the fruits and vegetable growing areas. This would not only prevent wastage but would also help to earn foreign exchange.

    There are also bright prospects for exporting fruit juices and pulps. By establishing modern plants, Pakistan can earn foreign exchange three times more than that being earned by export of fresh fruits and vegetables.

    Kinnosw: 
    Sunny winters in Pakistan yield a large variety of citrus fruits. The juicy kinno is a unique hybrid of two varieties of California Oranges. It has a soft skin which is easy to peel and has a lovely fragrance.

    Pakistan is fortunate in having great diversity in its soil and in its ecological and climatic conditions, ranging from extremely warm to temperate, to very cold. This enables the country to grow many kinds of trees, plants, shrubs, vines and creepers which yield a large variety of fruits and vegetables.

    Cotton Pests: Symptoms, Season and Control

    Plant protection strategy and activities have significant importance in the overall crop production programmes for sustainable agriculture. Variation of Bt gene expression in different cultivars over time and efficacy to bollworms are the main concern now a days, studies undertaken on Earias spp proved the concerned. Similarly the efficacy of Bt cotton in the field is losing efficacy against the pink bollworm, survey conducted revealed high infestations in green bolls. Monitoring of lepidopterous pest population viz sex pheromone and light traps was carried out and forecast the increasing trend in all bollworms population. Studies on red and dusky cotton bugs continued and efforts are made to find bio agents for long term solutions. Seed treatment effect and development of natural on early and normal planting studies revealed that the population of jassid was more on early sown field than normal sowing also the natural fauna was recorded higher in the early sown.
    [woo_product_slider id=”64262″]
    The distinct efforts of researchers of the section have proved meaningful in devising pest management strategies against common and new emerging insect pests through application of IPM. Studies are continued on host plant tolerance of CCRI, Multan and National Coordinated Bt. & non-Bt. Strains. The section also studied effect of different IPM strategies on insect pest for transgenic cotton. Screening of new insecticides was also conducted against major insect pests of cotton.

    Important pests of cotton:

    Name of pest Scientific Name Family Order
    Thrips Thrips tabaci Thripidae Thysanoptera
    Jassid Amrascadevastans Jassidae Hemiptera
    Whitefly Bemisia tabaci Aleyrodidae Homoptera
    Mealybug Phenacoccus solenopsis Psuedococcidae Hemiptera
    Red Cotton Bug Dysdercus cingulatus Pyrrhocoridae Hemiptera
    Dusky Cotton Bug Oxycarenus hyalipennis Lygaeidae Hemiptera
    Mites Tetranychustelarius Tetranychidae Acarina
    Pink bollworm Pectinophoragossypiella Gelechiidae Lepidoptera
    Spotted Bollworm Eariasvittella Noctuidae Lepidoptera
    spiny bollworm Eariasinsulana Noctuidae Lepidoptera
    American Bollworm Helicoverpa armigera Noctuidae Lepidoptera
    Armyworm Spodopteralitura Noctuidae Lepidoptera

     

    Symptoms of damage:

    Name of pest Symptoms of damage
    Thrips Leaves of seedlings become wrinkled and distorted with white shiny patches, older crop presents rusty appearance from a distance.
    Jassid Affected leaves curl downwards, turn yellowish, then to brownish before drying and shedding, “hopper burn” stunts young plants.
    Whitefly Upward curling of leaves, reduced plant vigour, lint contamination with honey dew and associated fungi, transmission of leaf curl virus disease.
    Mealybug The extraction of sap by the mealybug results in the leaves of the plant turning yellow and becoming crinkled or malformed, which leads to loss of plant vigour, foliage and fruit-drop, and potential death of the plant.
    Red Cotton Bug Feed on developing and mature seeds, stain the lint to typical yellow colour, reddish nymphs seen in aggregations around developing and open bolls.
    Dusky Cotton Bug Associated with ripe seeds, all stages characterized by a powerful smell, discolour the lint if crushed.
    Mites The first sign of damage is bronzing of the upper leaf surface near the petiole or leaf fold. As numbers increase, the leaves turn red and become covered in fine webbing, and affected leaves may dry and fall off.
    Pink bollworm “Rosetted” bloom pink larvae inside developing bolls with interloculi movement .
    Spotted Bollworm Bore mark in main shoot, dried and withered away shoot, twining of main stem due to auxillary monopodia, feeding holes in flower buds and bolls blocked by excrement.
    spiny bollworm Bore mark in main shoot, dried and withered away shoot, twining of main stem due to auxillary monopodia, feeding holes in flower buds and bolls blocked by excrement.
    American Bollworm Small amount of webbing on small squares injured by young larvae, squares have around hole near the base,larval frass and flaring of bracts on larger squares, clean feeding of internal contents of bolls, excessive shedding of buds and bolls.
    Armyworm Young larvae in groups skeletinise leaves and older larvae voraciously defoliate leaves .

     

    Seasonal occurrence of cotton pest in Pakistan:

    Name of pest Month of attack
    Thrips June and July
    Jassid July
    Whitefly July-September
    Mealybug October-November
    Red Cotton Bug October-November
    Dusky Cotton Bug Though our crop
    Pink bollworm August-November
    Spotted Bollworm July-September
    American Bollworm August-October
    Armyworm  

     
    List of natural enemies of cotton pest:

    Predator/Parasitoid Host Attack Stage
    Green lace wings, pirate bugs Lady bird
    beetle: Coccinella
    septempunctataMenochilus
    sexmaculatus, Brumodies sp. , Scymnus
    Thrips Nymph and adult
    Green lace wings Jassid All stages
    Lady bird beetle: Coccinella
    septempunctataMenochilus 
    sexmaculatus, Brumodies sp. , Scymnus 
    Eretnocerus serius
    Whitefly Egg and Numph
    Lady bird beetle: Coccinella
    septempunctataMenochilus 
    sexmaculatus, Brumodies sp. , Scymnus , 
    aenasius bamby wali.
    Mealybug Adult and larvae, adult
    Lady bird beetle: Coccinella
    septempunctataMenochilus 
    sexmaculatus, Brumodies sp. , Scymnus

    Shield bug Eucantheconidea furcellata 
    Apanteles angaleti 
    Elasmus johnstoni
    Pink bollworm Larvae
    Lady bird beetle: Coccinella 
    septempunctataMenochilus 
    sexmaculatus, Brumodies sp. , Scymnus
     
    Shield bug Eucantheconidea furcellata 
    Mirid bug Nesidiocoris tenius
    Spider: Oxyopes sp., Clubionia sp., Thomisus sp.
    Brachymeria nephantidis
    Spotted Bollworm Larvae
    Lady bird beetle: Coccinella
    septempunctataMenochilus 
    sexmaculatus, Brumodies sp. , Scymnus

    Shield bug Eucantheconidea furcellata 
    Spider: Oxyopes sp., Clubionia sp.,
    Thomisus sp.
    Trichogramma chilonis
    American Bollworm Larvae
    Aphidius colemani, Lady bird beetle:
    Coccinella septempunctataMenochilus
    sexmaculatus, Brumodies sp. , Scymnus
    Syrphid fly
    Aphid Egg, nymph and adults
    Anthocorid bug Orius minutus 
    Wasp Eumenes petiolata and Delta sp
    Mirid bug Nesidiocoris tenius 
    Spider: Oxyopes sp., Clubionia sp.,
    Thomisus sp.
    Armyworm Larvae

     
    Pesticides recommended for cotton pests control under different situations:

    Sr.# Pest situation recommended insecticide Dose / acre (ml/gm)
    1 Seed treatment to control sucking insect pests at an early stage. Imidacloprid 70 WS 
    Thiamethoxam 70 WS*
    10 gm/kg seed 
    5 gm/kg seed
    2 Thrips reached ETL, during early stage of crop and clear damage symptoms are visible. Chlorfenpyr 360SC
    Spinetoram 120SC
    Spinosad 240 SC
    Imidacloprid 200SL
    Acetamiprid 20 SP
    Formathion 25 EC
    Etofenprox 30 EC 
    Or Any other suitable registered insecticide
    100
    50
    50
    80
    50
    500
    200
    3 Whitefly population reached ETL, during early stage of crop. Diafenthiuron 500 SC
    Spirotetramate 240 SC
    Acetamiprid 20SP
    Imidacloprid 200 SL
    Buprofezin 20SC
    Pyriproxyfen 10.8EC
    Any other suitable registered insecticide
    200
    125
    150
    250
    600
    400
    4 Jassid population reached ETL, during early stage of crop. Dinotefuran 20SC
    Dimethoate 40EC
    Imidacloprid 200 SL
    Nitenpyram 10 SL
    Etofenprox 30 EC
    Thiamethoxam 25 WG Or
    Any other suitable registered insecticide
    100
    350
    200
    200
    200
    24
    5 Whitefly & Jassid collectively reached ETL during early stage of crop. Dinotefuran 20SC
    Dimethoate 40EC
    Imidacloprid 200 SL
    Nitenpyram 10 SL
    Etofenprox 30 EC
    Thiamethoxam 25 WG
    Mix with IGR
    Buprfoezin 20SC
    Pyriproxyfen 10.8EC
    100
    350
    200
    200
    200
    24 
    600
    400
    6 Pink bollworm reached ETL. Spinosad 240 SC
    Spinetoram 120 SC
    Spinetoram 250 WG
    Gamma Cyhalothrin
    Triazophos 40 EC
    Bifenthrin 10 EC
    Cypermethrin 10 EC
    Deltamethrin2.5 EC
    Tralomethrin
    Fenvalerate 20 EC 
    Or
    Any other suitable registered insecticide
    50
    100
    40
    100
    1000
    275
    333 / 365
    300
    80
    250 / 265
    7 Spotted bollworm reached ETL Spinosad 240 SC
    Spinetoram 120 SC
    Cypermethrin 10 EC
    Deltamethrin 2.5 EC
    Beta-Cyfluthrin 25 EC
    Cyhalothrin 2.5 EC
    Fenvalerate 20 EC
    Alpha cypermethrin 5 EC
    Or
    Any other suitable registered insecticide
    40
    40
    300 / 325
    333 / 365
    250 / 275
    333 / 370
    400 / 450
    440 / 490
    8 American bollworm reached ETL at early stage. Spinosad 240 SC
    Spinetoram 250 WG
    Chlorfenapyr 360 SC
    Emamectin Benzoate 1.9 EC
    Chlorpyrifos 40 EC
    Profenofos 500 EC
    Indoxacarb 150 SC
    Thiodicarb 80 DF
    Or
    Any other suitable registered insecticide
    100
    60
    333
    200
    1000
    1000
    175
    480
    9 Aphids reached ETL in later part of the crop life. Carbosulfan20 EC
    Diafenthiuron 500 SC
    Chlorpyrifos 40 EC
    Quinalphos 25 EC 
    Or
    Any other suitable registered insecticide
    500
    200
    750
    1250
    10 Mites reached ETL. Spiromesifen 240 SC
    Fenpyroxymate 5 SC
    Azocyclotin 25 WP
    Pyridaben 15 EC
    Amitraz 20 EC
    Diafenthiuron 500 SC
    Ethion 46 EC
    Triazophos 40 EC
    Chlorfenapyr360 EC
    Hexythiazox 10 WP 
    Or
    Any other suitable registered insecticide
    100
    200
    150
    500
    1000
    200
    1000
    600
    333
    220
    11 Armyworm attack on cotton.** Methoxyfenozide 240 SC
    Lufenuron 50 EC*
    Flubendamide 480 SC
    Emamectin Benzoate 1.9 EC
    Tebufenazide 20
    Acephate 75 SP
    Indoxacarb 150 SC
    Methomyl 42 SP***
    Or
    Any other suitable registered insecticide
    200
    200
    50
    250
    350
    750
    175
    500
    12 Black headed cricket. Bait
    Ingredients:
    1. Rice husk (Bhossi) 10 kg/acre
    2. Methamidophos½ litre
    3. Gur (Molasses) 1 kg
    4. Water As per requirement
    The formulated material is for one acre.
    13 Mealy bug infestation during early stage of crop. Acetamiprid 20 SP
    Imidacloprid 200SL
    150
    250
    14 Mealy bug infestation during late stage of crop. Profenofos 50 EC
    Methidathion 40 EC
    Chlorpyrifos 40 EC
    800
    400
    1000
    15 Dusky cotton bug. Fipronil
    Clothianidin
    Triazophos
    Imidacloprid + Fipronil
    480
    150
    660
    60
    16 Red cotton bug. Fipronil 5 SC
    Triazophos 40 EC
    Cypermethrin + Chlorpyrifos
    Triazophos + Deltamethrin
    Imidacloprid + Fipronil
    480
    660
    500
    600
    60

     

    Thrips: Pest of fruits, vegetables, flowers and fruits

    Thrips feed on the lower surface of leaves, buds, flowers and fruits. Both larvae and adults feed by piercing the plant tissue and sucking up the released plant juices. A heavy infestation causes premature wilting, delay in leaf development and distortion of leaves and young shoots. Under heavy infestations, when buds and flowers are attacked, abortion usually occurs. Thrips attack may also result in premature fruit shed. Thrips may also cause cosmetic damage to plants.

    Thrips feeding causes scarring of flowers and skin blemishes and distortion of fruits (scarring, russeting, fruit cracking or splitting), which affects fruit quality. In addition, egg-laying spots may be surrounded by slightly raised, light coloured areas, which may lead to rejection of banana, tomato or peas grown for the export market.

    Scientific Name:

    Ceratothripoides brunneus, Diarthrothrips coffeae, Frankliniella schultzei, Frankliniella occidentalis, Haplothrips spp., Heliothrips haemorrhoidales, Hercinothrips bicinctus, Megalurothrips sjostedti, Scirtothrips aurantii, Scirtothrips kenyensis, Thrips tabaci

    Order / Family:

    Thysanoptera: Thripidae

    Type of Pest:
    Insect

    Host Plants:

    Avocados, Bananas, Beans, Cabbage/Kale, Brassicas, Cashew , Citrus plants, Coffee, Cowpea, Eggplant, Green gram, Groundnut, Mango, Okra, Onion, Passion fruit, Peas, Peppers, Pigeon pea, Pineapple, Tea, Tomato, Wheat

    Thrips also cause indirect damage as vectors of disease-causing virus, fungi and bacteria. Several species of thrips are vectors of the tomato spotted wilt virus group in a wide range of crops (bell pepper, lettuce, pea, tobacco, potato, tomato, groundnut and a large number of ornamental plants). In addition, injuries caused by thrips feeding may serve as entry point for bacterial or fungal pathogens. For example infection by Fusarium ear rot on maize is facilitated by the western flower thrips, and purple blotch in onions by the onion thrips.

    The stage of growth when an infestation occurs seems to determine the extent of yield loss. Direct feeding damage is most harmful in dry climate and conditions, when heavily attacked plants lose moisture rapidly. Young plants are particularly susceptible, and there may be total losses at the seedling stage in onions, cabbages and cotton.

    Major species of thrips attacking crops in Africa:

    African bean flower thrips (Megalurothrips sjostedti)
    Coffee thrips (Diarthrothrips coffeae)
    Blossom or Cotton bud thrips (Frankliniella schultzei)
    Black tea thrips (Heliothrips haemorrhoidales)
    Banana thrips (Hercinothrips bicinctus)
    Citrus thrips (Scirtothrips aurantii)
    Cacao or red banded thrips (Selenothrips rubrocinctus)
    Tomato thrips (Ceratothripoides brunneus)
    Cereal thrips (Haplothrips spp)
    Tea thrips (Scirtothrips kenyensis)
    Onion thrips (Thrips tabaci)
    Western flower thrips (Frankliniella occidentalis)

    Host range

    Thrips attack a wide number of vegetables, fruit and flower crops and cereals. Some species are specific to particular host plants while other feed on many host plants. Both onion thrips and western flower thrips attack a wide range of plants including cereals and broadleaved crops.

    Symptoms

    The characteristic symptom of attack is a silvery sheen of the attacked plant tissue, and white or silvery patches and streaks on leaves, fruits and pods. Affected tissue will dry up when the damage is severe. A further indicating of attack by thrips is small black spots of faecal material on the infested parts of the plant. However, small dark spots can also be observed on plants attacked by other insects such as lace bugs. Damaged leaves may become papery and distorted. Infested terminals lose their colour, roll, and drop leaves prematurely. Feeding on fruits leaves a roughened silvery texture on the skin.

    Affected plant stages

    Flowering stage, post-harvest, seedling stage and vegetative growing stage.

    Affected plant parts

    Growing points, inflorescence and leaves.

    Symptoms by affected plant part

    Growing points: dead heart.
    Inflorescence: lesions; abnormal colour; abnormal forms.
    Leaves: lesions; abnormal colours; abnormal forms.

    Biology and Ecology of Thrips

    Eggs are very tiny. A single egg is 0.25 mm long and 0.1 mm wide. They are white when freshly laid and turn pale yellow toward maturation. Eggs are usually laid singly inside the plant tissue, and are therefore not visible. Some thrips (e.g. Haplothrips spp) lay eggs singly or in clusters attached to the plant surface.

    Larvae. The first and second instar larvae are very small (0.5 to 1.2 mm), elongated, slender, and vary in colour from pale-yellow, orange or red according to the species. They have piercing-sucking mouthparts. They resemble a miniature version of the adults but do not have wings.

    Pre pupa and pupae. These two or three instars are intermediate forms between the nymph and the adult. They have short wing buds but no functional wings. During these stages thrips are inactive and do not feed and therefore they do not do cause any damage to the plant. Pupation may occur on a plant or in the soil beneath, depending on species.

    Adult thrips are small (usually 1 to 1.5 mm), slender and usually winged. The wings are long, narrow and fringed with long hairs, and at rest, are tied on the back along the body. Their colour varies according to the species. Most species are black, brown or yellow 

    Pest and Disease Management

    Pest and disease management: General illustration of the concept of Infonet-biovision

     
     

    This illustration shows the methods promoted on infonet-biovision. The methods shown at the top have a long-term effect, while methods shown at the bottom have a short-term effect. In organic farming systems, methods with a long-term effect are the basis of crop production and should be of with preference. On the other hand methods with a short-term effect should be used in emergencies only. On infonet we do not promote synthetic pesticides. 
     

    Further below you find concrete preventive and curative methods against Thrips.

    Cultural practices

    Monitoring and decision-making

    Monitor the crop regularly. Early detection of thrips is important to determine an appropriate control strategy. In the case of onions, randomly sample plants and evaluate thrips numbers and damage under leaf folds. Sample at least 5 plants from 4 separate areas of the field. (For more information on monitoring and damage thresholds (click here to see datasheet on onions). In other crops pay particular attention to flower buds and flowers. Thrips can be easily detected by shaking leaves and flowers on a white piece of paper.

    Adult thrips can be monitored by mass trapping with coloured (blue, yellow or white) sticky traps or water traps in the nursery or field.

    The type of crop damage needs to be taken into consideration when deciding on the need for control measures and the appropriate strategy. This is particularly important in the case of thrips-transmitted virus diseases. The prevention of these diseases is difficult since relatively small numbers of vector thrips can result in high rates of pathogen spread. In general, transmission of the plant pathogen occurs so quickly that the thrips are not killed before they have transmitted the virus to the plants. In these cases, the best strategy is to keep the crop free of thrips at least during the most vulnerable period of the crop (i.e. young growth).

    Irrigation

    Provide good growing conditions for the plants to ensure rapid growth. Environmental stress that weakens plants makes them more susceptible to thrips attack. In particular, plants under water stress are very susceptible to direct thrips damage. Adequate irrigation is a critical factor in minimising damage.

    Tillage

    Ploughing and harrowing, and solarisation can kill pupae in the soil from previously infested crops.

    Planting date

    Well-established crops can withstand attack better than newly planted, therefore early planting is desirable particularly in rain-fed crops. This is especially beneficial in light, dry soils, where it is common for plants to suffer from water shortage as the growing season progresses.

    Intercropping

    In some cases intercropping has been found to reduce thrips infestation. The effects are probably caused through shading of the lower crop by the taller intercrop, which influences the abundance and activity of the thrips. However, thrips reduction is not necessarily translated in yield increase. The effect of intercropping on thrips numbers and damage depends, among other factors, on the selection of plants. In some cases intercropping does increase the numbers of thrips in susceptible crops. Thus, populations of the onion thrips increase on potatoes when intercropped with shallot and garlic, as does Caliothrips indicus on groundnuts intercropped with pigeon pea and mung bean. A mixed cropping habitat is likely to encourage thrips predators, as has been shown for the minute pirate bugs (Orius tristicolor) (Parella and Lewis, 1997)

    In Egypt, intercropping onion and garlic with tomato reduced infestations of the onion thrips by almost 80%, but the yield of both crops declined. In England, infestation of the onion thrips (Thrips tabaci) on onions was halved when intercropped with carrots. The effect was greater with closely alternating single rows of each. Infestation of the onion thrips on cabbage was reduced tenfold by growing clovers (Trifolium repens or T. subterraneum)between rows (Parella and Lewis, 1997).

    In Kenya, populations of the African bean flower thrips (Megalurothips sjostedti) and Hydatothrips adolfifriderici on cowpea buds were almost halved by intercropping the cowpea with sorghum and maize (Parella and Lewis, 1997)

    Crop rotation

    Avoidance of successive planting of susceptible crops helps reduce the impact of thrips. Identification of the thrips involved is important to know the host range of crops adequate for crop rotation. Thus, in the case of onions, they should not be planted near grain fields.

    Biological pest control

    Natural enemies

    Natural enemies, in particular predators are often found feeding on thrips. They include predatory thrips, predatory mites (e.g. Amblyseius spp.) anthocorid bugs or minute pirate bugs (Orius spp.), ground beetles, lacewings, hoverflies, and spiders. They are important in natural control of thrips. The parasitic wasp Ceranisus menes is an important natural enemy. The farmer can increase the number of these natural enemies by providing protective habitats for them. For more information on natural enemies click here.

    Pathogens such as the fungi Entomophthora, Verticillium lecanii, Beauveria bassiana and Metarhizium anisopliae are also important in natural control of thrips. Spray formulations of Beauveria bassiana are used for the control of thrips. Thismicroorganism is most effective when used early before large thrips populations have built up.

    The natural enemies Beauveria bassiana, Orius jeanneliand Amblyseius californicus are commercially available in Kenya (reference addresses see below)

    Biopesticides and physical methods

    Spinosad

    Spinosad, a microbial insecticide, is very effective in controlling thrips. This biopesticide is derived from the fermentation of an Actinomyces bacterium, commonly found in the soil. In Kenya, this microbial pesticide is sold as Tracer 480 SC(r).

    Neem

    Neem-based pesticides are reported to control young nymphs, inhibit growth and development of older nymphs, and reduce egg-laying by adult thrips. Adding 0.1 to 0.5% of soft soap enhances efficacy of neem-based pesticides.
    For more information on Neem click here

    Other botanicals and measures

    Other botanical pesticides that have been recommended for management of thrips include garlic, rotenone, ryania, pyrethrum and sabadilla. A homemade botanical spray of garlic and pepper has been recommended for organic growers in USA (ATTRA, 2004). The garlic/pepper mixture is made by liquifying two bulbs of garlic and two cayenne or habanero (hot) peppers in a blender 1/3 full of water. Solids are strained out, and enough water is added to make one gallon of the concentrate. The spray solution is prepared by mixing 1/4 cup of the concentrate with 2 tablespoons of vegetable oil and enough water to make 1 gallon (about 22 litles) (ATTRA, 2004). For more information on garlic recipe click here.

    Sulphur, insecticidal soaps and diatomaceous earth have demonstrated efficacy in suppressing thrips in several crops. Three applications of superfine sulphur at monthly intervals are recommended in fruit crops. Lime sulphur has also been recommended as an alternative. However, care should be taken when using sulphur as it has been reported to harm some predatory mites.

    Flour/starch preparations have been recommended for control of thrips. For more information on Flour preparation click here.

    Coloured sticky traps (blue, yellow or white) or water traps are useful for monitoring and in some cases reducing thrips by mass trapping them in the nursery or field. Research in California has shown that hot-pink sticky cards attract more thrips than blue-coloured traps. The colour spectrum of the boards is important for the efficacy of the sticky traps. Bright colours attract more thrips than darker ones. For more information on sticky traps click here.

    Overhead irrigation and rainfall reduce thrips numbers. Irrigation by flooding fields has been found to reduce thrips damage. It destroys a large proportion of pupae in the soil.

    Ultraviolet-absorbing plastics, used to build walk-in field tunnels have proved effective in protecting crops from western flower thrips.

    Reflective mulches deter thrips. Aluminium-surfaced mulch (e.g. coated plastic mulch) has considerably decreased thrips and virus infection in tomato, pepper and tobacco. The effectiveness of the mulch decreases with increased shading by lower leaves (Lewis, 1997).

    Information Source Links

    ATTRA. 2004. Thrips Management Alternatives in the Field. By George Kuepper. NCAT agriculture specialist. ATTRA publication #IP132.https://attra.ncat.org
    Crop Protection Compendium, 2005 Edition. CAB International, Wallingford, UK, 2005 www.cabi.org
    Lewis, T. (1997). Field and Laboratory Techniques. In Thrips as crop pests (1997). Edited by T. Lewis. CAB International. Institute of Arable Crops Research – Rothamsted, Harpenenden, Herts, UK. Pages 435-475. ISBN: 0-85199-178-5.
    OISAT: Organisation for Non-Chemical Pest Management in the Tropics. www.oisat.org
    Parella, M. P. and Lewis, T. (1997). IPM in Field Crops. In Thrips as crop pests. (1997).. Edited by T. Lewis. CAB International. Institute of Arable Crops Research – Rothamsted, Harpenenden, Herts, UK. Pages 595-614. ISBN: 0-85199-178-5.
    UC Pest Management Guidelines: How to Manage Pests. Onion and Garlic Thrips. UC IPM Online. Statewide Integrated Pest Management Program. University of California. Agriculture and Natural Resources. www.ipm.ucdavis.edu
    Varela, A.M., Seif, A.A., and Lohr, B. (2003). A Guide to IPM in Tomato Production in Eastern and Southern Africa. ICIPE, Nairobi, Kenya. ISBN: 92 9064 149 5 www.icipe.org

    Use of Neem in Pest Control

    Neem can be used against the following pests (clicking on underlined pests takes you to pests’ page): African armyworm, African bollwom, Aphids, Banana weevil, Cabbage looper, Cabbage moth, Cabbage webworm, Coconut mite, Cutworms, Diamondback moth, Giant looper

    [ads-pullquote-left]Scientific name: Azadirachta indica[/ads-pullquote-left]

    The neem tree has over 100 compounds with pesticidal properties. The best known is azadirachtin. This substance is found in all parts of the tree, but it is much more concentrated in the fruit, especially in the seeds.

    [woo_product_slider id=”64262″]

    Neem is unique among plants with pesticidal properties since it has so many different effects on pests. It acts as a broad-spectrum repellent, insect growth regulator (it causes deformities in the insects’ offspring) and insect poison. It discourages feeding by making plants unpalatable to insects or suppresses the insect’s appetite (anti-feedant effect); if they still attack, it inhibits their ability to moult and lay eggs. Unlike most botanical insecticides, neem also has a somewhat “systemic” effect. This means that plants can take up neem extracts through their roots and leaves, spreading the material throughout the plant tissues. For this reason neem can help control pests like leafminers, which feed within leaves and are normally not affected by sprays that only cover the outer parts of the plant.

    Farmers and scientists have also observed a certain preventive effect of neem oil or seed extract against plant diseases such as mildews and rusts.

    Neem products are effective against a wide range of pests; about 400 species of crop pests are known to be affected by neem extracts. In spite of its broad-spectrum action, neem products generally, would not harm natural enemies (like wasps, ladybird beetles, spiders, etc.). This is explained by the special mode of action of neem compounds, and by the feeding behaviour of natural enemies as well as the relatively low contact effect of neem products. The degree of effects on natural enemies is largely dependent on the type of formulation, and time, frequency and methods of applications.

    Adults of predatory insects are apparently not affected by dosages of neem products recommended for effective pest control. However, their activity, fecundity and longevity may be negatively affected with high dosages. Hoverflies are one of the most sensitive groups to neem applications. Parasitoids are in general less sensitive to neem products than predators. However, especially in very small species of parasitic wasps, treatment of the developmental stages of the host (for instance eggs or puparia of whiteflies) may have negative effects on the emergence rate, walking ability, searching ability, longevity and fecundity of the natural enemy.

    In general, neem products based on neem oil or with high oil content have more or stronger side effects on non-target organisms than oil-free preparations. Thus, their application should be avoided or restricted on crops where natural enemies play an important role in pest control.

    Some neem products, especially the ones with high oil content, are phytotoxic to some plants, this means plants may be burned when neem extract is used at a high dosage. Therefore, the extracts should be tested on few plants before going into full scale spraying.

    Neem based pesticides are suitable for organic farming and for use in developing countries because leaf or seed extracts can easily be prepared without the use of expensive and complicated equipment. However, neem extracts are rapidly ‘destroyed’ when exposed to sunlight (UV, ultra-violet rays), which means they will loose their efficacy. For this reason, commercial products usually contain a sunscreen, which protects the extract from sunlight, allowing a longer exposition to sunlight.

    The effect of neem as a pesticide depends on the concentration of the active principles, on the formulation, on the pest type and on the crop.

    Neem pesticides can be prepared from the leaves or from the seeds. The leaves or seeds are crushed and steeped in water, alcohol, or other solvents. For some purposes, the resulting extracts can be used without further refinement. Ground neem seeds or neem kernel powder (before or after oil extraction) is used as a soil amendment, and it is effective for control of nematodes. It is also used for control of stalk borers, and to prepare water extracts, which are then sprayed onto plants. See more information on stemborer datasheets

    Neem has also been used to protect stored roots as well as tubers against the potato moth. Small amounts of neem powder are said to extend the storage life of potatoes for 3 months. See more information on the potato datasheet

    Neem oil, extracted from the seed kernels, gives effective protection to stored beans, cowpeas, and other legumes.

    In recent years, there have been a number of studies conducted to investigate the particular effects of neem extracts on malaria-transmitting mosquitoes. There are indications that the most effective way to use neem is to apply seed extract to breeding sites when population numbers are low, during the dry season, in order to eradicate as many immature mosquitoes as possible and reduce the population available for breeding when conditions become more favourable. Once the rainy season commences, regular applications of seed extract should continue to prevent immature mosquitoes from emerging as adults (Gianotti et al. 2008).

    Use as an insecticide: The seeds are the primary source of insecticides. They can be used in the form of simple aqueous extracts or as a basic raw material for formulated pesticides. The leaves are also used as simple aqueous (water) extracts.

    Use as a nematicide: The neem cake, a by-product of oil extraction from the seeds, worked into the soil has shown to reduce to a considerable extent the reproduction and population density of numerous plant pathogenic nematode species.

    Use as a fungicide: One of the latest discoveries is neem’s potential application in the control of fungi that cause diseases to plants. Neem oil based emulsions have proven to be the most effective.

    Use as a molluscicide and acaricide (miticide): These pests are only controlled on to a limited extent with neem. Neem showed deterrent effects on land snails. Alcoholic extracts, in particular, have a negative effect on the reproduction of spider mites.

    The susceptibility of different groups of pests to neem products is shown in the table below.

    Pests  Level of control Recommended neem formulation
    Beetle larvae, butterfly and moth caterpillars excellent aqueous neem extracts
         
    Stalkborers good aqueous neem extracts and neem cake, neem powder 
    True bugs, plant- and leaf- hoppers grasshoppers good neem oil, neem kernel extracts
    Grasshoppers good neem oil
    Adult beetles good/fair aqueous neem extracts, neem cake powder, leaves, neem oil 
    Thrips, fruit flies, scale insects, mealybugs fair/poor neem oil, aqueous neem extracts
    Mites fair/poor alcoholic extracts 
    Aphids and whiteflies good/fair neem oil
    Plant parasitic nematodes good neem cake, neem leaves
     

    Standard Procedures for the Preparation and Application of Neem Extracts

    Select healthy neem leaves that are free from diseases.
    When storing the plant parts for future usage, make sure that they are properly dried and are stored in an airy container (never use plastic container), away from direct sunlight and moisture. Make sure that they are free from moulds before using them.
    Use utensils for the extract preparation that are not used for your food preparation drinking and cooking water containers. Clean all the utensils properly before and after use.
    Do not have direct contact with the crude extract while in the process of the preparation, and during the application.
    Make sure that you place the neem extract out of reach of children and house pets while leaving it overnight.
    Harvest all the mature and ripe fruits on the crop to be sprayed before neem application.
    Always test the plant extract formulation on a few infested plants first before going into large scale spraying. When adding soap as an emulsifier, use a potash-based one such as gun soap (Kenya).
    Wear protective clothing while applying the extract.
    Wash your hands after handling the plant extract.

    Neem water can be stored and will remain effective for 3 to 6 days if it is kept in the dark.

    1. Collect fallen neem fruits from underneath the trees.
    2. Remove the flesh from the seeds and wash away any remaining shreds. In some regions in Africa such as the Indian Ocean Coast in Kenya and Tanzania the seeds need not be taken off the tree or pulped when collected, as large colonies of fruit bats pluck the ripe fruit off the tree, during the night, suck off the sweet outer skin and then spit out the seed, which can be found lying under the trees the next morning.
    3. Dry the seeds in airy conditions (in sacks or baskets) to avoid formation of mould.
    4. When needed, shell the seeds, grate them finely, and soak them overnight in a cloth suspended in a barrel of water. Dosage: 50g of neem powder per litre of water. This solution is then sprayed on infested plants.

    Detailed recipe to prepare 10 litres of Neem Seed Kernel Extract (NSKE):

    1. Grind 500 grams (g) of neem seed kernels in a mill or pound in a mortar.
    2. Mix crushed neem seed with 10 litres of water. It is necessary to use a lot of water because the active ingredients do not dissolve easily. Stir the mixture well.
    3. Leave to stand for at least 5 hours in a shady area.
    4. Spray the neem water directly onto vegetables using a sprayer or straw brush. Neem water can be stored and will remain effective for 3 to 6 days if it is kept in the dark.

    Precautions in using Neem Extracts/Formulations:

    1.) Neem is almost non-toxic to mammals and is biodegradable. It is used in India as an ingredient in toothpaste, soap, cosmetics, pharmaceuticals and cattle feed. The leaves are used for tea. See datasheet on neem as a medicinal plant for more information. However, the seeds and extracts of both neem and chinaberry trees are poisonous if consumed. Neem trees are very often confused with the Persian lilac or chinaberry tree a relative of neem, which thrives a in high altitudes, whereas neem thrives at low altitudes (up to 1200 m).
    2.) Because neem’s chemical structure is so complex (the tree has many different compounds, many functioning quite differently and on different parts of an insect’s life cycle and physiology), scientists believe it will take a long time for insects to develop resistance to it. However, to minimise the chance of affecting beneficials (natural enemies) and discouraging development of pest resistance, use neem sprays only when absolutely necessary, and only on plants you know are affected by pests.
    3.) Neem extracts do not kill insect pests immediately. They change the feeding behaviour and life cycle of the pests until they are no longer able to live or reproduce. Effects are often not visible before 10 days after application. Consequently, severe pest attacks will not be controlled within time. For a reliable and satisfying control, neem extracts must be applied at an early stage of pest attack.
    4.) Neem products break down fairly quickly, usually within 5 to 7 days in sunlight and in the soil, so you may need to repeat the application during the growing season to deal with new pests that arrive from outside during this time.
    5.) Neem works fastest during hot weather. Heavy rains within a few days of application may wash off the protective cover of neem on plants. Reapply if pests are a problem.
    6.) If crops have to be watered, water should be targeted to the soil because water running over the leaves of sprayed plants may wash off the neem water extract.

    References:

    Ellis, B.W. and Bradley, F.M. (1992). The Organic Gardener’s Handbook of Natural Insect and Disease Control. Rodale Press. ISBN:0-87596-753-1
    HDRA. Leaflet The Neem tree, see also online under www.gardenorganic.org.uk
    Hellpap, C. (1995). Practical results with neem products against insect pests, and probability of development of resistance. Pest of selected field crops. Corn. In The Neem tree- Source of Unique Natural Products for Integrated Pest Management, Medicine, Industry and Other Purposes. Ed. by H. Schmutterer. pp 385-389. ISBN: 3-527-30054-6.
    Lemmens, R.H.M.J., Soerianegara, I., Wong, W.C. (1995). Plant resources of Southeast Asia No. 5 (2). Timber trees: minor commercial timbers. Leiden, Netherlands: Backhuys Publishers.
    Maundu, M. and Tangnas, B. (2005). Useful trees and shrubs for Kenya. World Agroforestry Center.
    Schmutterer, H. (Ed.) (1998). The Neem tree- Source of Unique Natural Products for Integrated Pest Management, Medicine, Industry and Other Purposes. pp 385-389. ISBN: 3-527-30054-6.
    Siddiqui, K.M. (1995). Neem, its occurrence, growth and uses. Peshawar, Pakistan: Pakistan Forest Institute.
    Tewari D.N. (1992). Monograph on neem (Azadirachta indica A. Juss.). Dehra Dun, India: International Book Distributors.
    Gianotti, R. L.; Bomblies, A.; Mustafa Dafalla, M. Issa-Arzika,I., Duchemin, J-B and Eltahir, E. AB. (2008). Efficacy of local neem extracts for sustainable malaria vector control in an African village. Malaria Journal 2008, 7:138 doi:10.1186/1475-2875-7-138. www.malariajournal.com

    Population Dynamics of Aphids and their Natural Enemies Associated with Strip- Intercropping in Wheat Crop

    Population Dynamics of Aphids and their Natural Enemies Associated with Strip- Intercropping in Wheat Crop
    Muhammad Arshad,1* Sajjad Ahmad1, Muhammad Sufyan1, Zain-ul Abdin1
    and Sumaira Maqsood2
    1Department of Entomology, University of Agriculture, Faisalabad
    2Institute of Agricultural Sciences, University of the Punjab, Lahore
    ABSTRACT
    Aphids are considered serious pests of many agricultural crops worldwide. The present study was conducted to assess the wheat aphids’ diversity and their predators association with strip intercropping (brassica, alfalfa, berseem and garlic) and wheat monoculture. Results showed that the first aphid was seen in the last week of January while the predator population was first recorded during the first week of March. Aphid population was maximum on wheat monoculture when 130 specimens were recorded per tiller. Among strip cropping garlic showed maximum population (113 per tiller) followed by brassica (105), berseem (98) and alfalfa (83 per tiller). Second week of March was the most favorable period when
    11.48 per tiller of aphid population counted in wheat monoculture, while no specimens were noticed after the first week of April. The coccinellid and syrphid fly showed a maximum population of 1.3 and 1.1 per plant in wheat monoculture respectively in the third week of March, The garlic (1.1/plant) and brassica (0.8/plant) showed maximum population while minimum population of coccinellid recorded in berseem (0.6 per plant) and alfalfa (0.5 per plant). Similar population level was reported in different strip cropping for syrphid fly. Our findings suggest, the strip intercropping promote species composition; richness and abundance in general and predators in particular.
    INTRODUCTION
    Tylianakis et al., 2004). Many entomologists and ecologists advocate the strip-intercropping as an important tool in integrated pest management to suppress the insect pests’ community and encourage the natural enemies’ diversity (Andow, 1991; Landise et al., 2000).onoculture cultivation of genetically homogeneous groups  over  long  period  of  time  promote  the adaptations of various insect pests (Altieri and Rosset, 1995) and enable them to locate their host plants more easily than in mixed cropping (Root, 1973). Strip-intercropping is an important agricultural technique that has been practiced in many parts of the world (Theunissen and Den-Ouden, 1980; Trenbath, 1993) and indigenous people throughout the world for reducing crop losses by insect pests. Historically strip-intercropping has the potential to reduce insect pests, increased production, improve soil fertility and greater use of environmental resources. In many studies by practicing intercropping about 53% of experiments showed reduced insect pests while only 18% increased the pest population than the pure cropping (Francis, 1989). Additionally strip- intercropping  enhance  the  provision  of  floral richness for  insect  predators  and  parasitoids  in  agro-ecosystem and  increase  the  effectiveness  of  natural  enemies  by parasitism, fecundity and longevity (Wratten et al., 2002;
    Among insect pests aphids (Aphididae: Homoptera) are serious pests of many agricultural crops like oilseeds, fruit trees, vegetables and cereals (Bowling et al., 1998; Yahya et al., 2017) and occur throughout the world. They may attack on different plant portions including leaves, stems, fruits, roots and are responsible for considerable damage by direct feeding, transmission of viral diseases, injection of toxins and honeydew contamination of different plant parts. The aphid population has been increasing from the last few years and has become as a regular sucking pest of wheat (Triticum aestivum L.) crop in Pakistan. Wheat is a major crop with largest area under cultivation in Pakistan and plays a significant role in the livelihood of people. Low yield of wheat per hectare in the country is related to several abiotic and biotic factors including traditional methods of cultivation, low yielding varieties, lack of irrigation, soil fertility problems and incidence of insect pests and diseases. Among insect pests aphids are considered major constraint for increased wheat production in Pakistan (Khattak et al., 2007; Aheer et al.,
    2006). They cause yield losses either directly (35-40%), sucking the plant sap or indirectly (20-80%) by transmitting viral and fungal diseases (Aslam et al., 2005). Management of aphids depends heavily on insecticides and often to the elimination of other control methods. Widespread use of insecticides is not generally worthwhile economically as some insect pests have become resistant and some non- target  organisms  are  adversely  affected.  Additionally the toxic and chronic effects of pesticides have not only caused environmental and health concerns but also serious lethal effects to the natural enemies of agricultural pests. This shift in control strategy has caused increased interest in long-term biological control techniques to curtail the reliance on insecticides for sustainable agriculture. Strip intercropping has the potential to offer valuable food resources to an agro-ecosystem for the enhancement of beneficial insect population and their fitness (Landise et al., 2000; Irvin and Hoddle, 2007) that leads to an effective biological control of insect pests.
    In this study population dynamics of wheat aphids and their natural enemies (Coccinelids and Syrphids) were evaluated in strip intercropping of wheat with brassica, alfalfa, berseem and garlic over sole wheat cropping. The study will provide a good understanding of population dynamics will help to determine the role of strip crops as a source of predatory insects to suppress aphid population that is significant for crop protection.
    MATERIALS AND METHODS
    Study area
    Field experiments were carried out in Ayub Agriculture Research Farm, Faisalabad (latitude 31°26’N and 73°06’E, altitude 185 m) during the winter season of 2012-2013 to determine the diversity of aphids with respect to their predators under field conditions. The climate is hot with annual average temperature of 24.5°C and the precipitation is less than 500 mm. The crop rotation at research station includes wheat, cotton, sugarcane, rice, brassica, alfafa, berseem etc. and historically has been managed conventionally.
    Experimental design and treatments
    The trial was conducted in Randomized Complete Block Design (RCBD) in three replicate blocks having five treatments (T1: strip of brassica sandwiched within wheat, T2: strip of berseem sandwiched within wheat, T3: strip of Garlic sandwiched within wheat, T4: strip of alfalfa sandwiched within wheat, T5 (control): sole cropping of wheat) in each block. In each treatment wheat was planted in east-west orientation in alternate 15 feet wide strips to a sandwiched 30 feet selected crop (brassica, berseem,
    garlic and alfalfa) with 15 feet length for both crops. All treatment plots were 0.5 m apart and each block was 10 feet  apart  separated  by  bare  ground.  Dates  of  sowing were November 20 for wheat and for selected crops using as strips. All plots were given identical fertilizers and irrigation and kept free from insecticides, herbicides and weeds. The number of aphids and predators were recorded at 7-day intervals from 24 January to 4 April from each plot. The number of aphids and mummies from ten tillers of randomly selected plants from each replication of each treatment were counted on weekly basis. The sample was taken from three sites in each plot and in each sampling site, ten wheat tillers were randomly selected and were used as a sampling unit, 3 units (30 wheat tillers) were sampled from each plot, and the number of aphids was counted on all tillers. Adults and larvae of coccinellids while the maggots of syrphid fly were recorded from ten plants per replication for each treatment on weekly basis.
    Data analysis
    The obtained data for predators and aphid population were analyzed using ANOVA with SPSS10.0 software and means were compared using LSD (P = 0.005) test. Excel software was used to draw figures.
    RESULTS
    The population densities of wheat aphid, coccinelids and syrphid fly were significantly varied among all treatments (Table I). The results showed that the abundance of  aphids  and  predators  were  significantly different  in strip crop and wheat monoculture techniques. Similarly a  significant interactive  effect  of  treatments  with  strip cropping and monoculture techniques was recorded.
    Table I.- Analysis of variance regarding different treatments and techniques to aphid and predatory species.

    Insects Effect DF F P
    Aphid Treatments 4*/20** 319.90 0.00
      Techniques† 1*/20** 374.13 0.00
      T×T 4/20 192.87 0.00
    Coccinellid Treatments 4*/20** 29.54 0.00
      Techniques† 1*/20** 429.86 0.00
      T×T 4/20 4.40 0.01
    Syrphid fly Treatments 4*/20** 27.01 0.00
      Techniques† 1*/20** 308.05 0.00
      T×T 4/20 14.92 0.00

     
    *Total treatments; ** Error; †, Strip and without strip crop; d.f = 29.
    Regarding per tiller the aphid population was maximum on wheat monoculture when 130 specimens were recorded. Among strips cropping garlic showed maximum aphid population (113 per tiller) followed by brassica (105 per tiller), berseem (98 per tiller) and alfalfa crop (83 per tiller). The second week of March found to be the most favorable period which showed maximum population of wheat aphids (11.48 per tiller) in wheat monoculture. There was considerable drop in population during the last week of March, while no capturing was recorded after the first week of April when the crop becomes matured. Similarly the adults and larvae of coccinelids showed maximum population (1.3/plant) in the third week of March, while reduced during the last week. The garlic (1.1/plant) and brassica (0.8/plant) showed maximum population while minimum population of coccinelids recorded in berseem (0.6 per plant) and alfalfa (0.5 per plant). Similarly the syrphid  fly  displayed  maximum  population  (1.1/plant)
    population  of  aphid  was  recorded  in  brassica  strip followed by wheat monoculture treatment (Fig. 1). Garlic strip showed significantly lower level of aphid population to all other strip (except alfalfa) and monoculture cropping system. The results showed that observational dates varied meaningfully in response to coccinelid and syrphid fly species per plant whereas the variation among different treatments revealed slight difference in total capturing. A significant lower level to all other treatments was recorded in wheat monoculture for both predatory species (Fig. 1).
     
    Table III.- Correlation coefficient of aphid with coccinelid and syrphid fly population for different treatments with stripping and non-stripping culture (LSD = 0.05).
    Aphid                  Coccinelid                         Syrphid fly
    Strip       Non-Strip          Strip       Non-Strip
    during the third week of March, while decreased during the last week of March.+ 0.504 (0.055)Table II.- Pair-wise comparison tests for aphid, coccinelid and syrphid fly population for different treatments with strip cropping and non-stripping culture (LSD = 0.05).
    _ 0.544 (0.036)
    + 0.440 (0.101)
    _ 0.179 (0.523)
     
    Treatments          Aphid            Coccinelid        Syrphid fly
     

      Strip Non- Strip Strip Non- Strip   Strip Non- Strip
    Brassica 29.69a 22.90b 0.19c 0.35a   0.14c 0.22a
    Berseem 4.13e 12.05c 0.16c 0.32a   0.13cd 0.19b
    Garlic 2.09f 9.36d 0.16c 0.33a   0.13cd 0.21ab
    Alfalfa 5.09e 8.49d 0.15c 0.35a   0.11d 0.20ab
    Control 0.00g 29.62a 0.00d 0.26b   0.00e 0.19b

    Population level of aphids and predators in differentComparison tests showed that the overall aphid population found on non-strip cropping was significantly different from the strip cropping culture except the brassica  strip  which  was  significantly  higher  than  all other  treatments  except  for  non-strip  control,  where the population was also significantly greater (Table II). Similarly coccinelid population on non-strip crops showed significantly higher population to all strip cropping treatments. The population dynamic of syrphid fly also showed  similar  trend  of  significant higher  numbers  in wheat monoculture compared to strip crop population. There was a positive correlation of aphid with coccinelid population on strip crops, while negatively correlated on non-strip cropping (Table III). Similar trend of correlation was noticed between aphid and syrphid fly population on both strip and wheat monoculture. A significant maximum
    strip crops (brassica, berseem, garlic, alfalfa and control). Means with same lowercase letters are not significantly different at α = 0.05 (LSD test).
    DISCUSSION
    The distribution, species richness and diversity of predators depend on plant communities, food availability and faunal history. Intercropping system play an important role in predators’ diversity that has great impact in biological  control  especially  of  important  pests  like aphids. In the present study we investigated the effect of strip cropping with wheat on population density of aphid and their predator species. Our results provided the evidence that the strip cropping enhances the abundance of natural enemies and resultantly suppresses the aphid population  except  the  brassica  strip  where  both  aphid and the predatory population was higher than wheat monoculture. The brassica crop is taller, having different colour, odor and smell to wheat crop that might affect the movement of aphids as well as the predators. This disruptive crop assumption is equivalent to Root (1973) hypothesis that herbivores in polycultures having more difficulties in finding crop plants associated with one or more taxonomically or genetically different plants than finding crop plants in monocultures (Vandermeer, 1989). Finch and Collier (2000) suggested that herbivores tend to land on taller green plants make the main crop less apparent, a useful mechanism of camouflage hypothesis incorporates the visual stimuli (color and height) induces the herbivores to land on plants. Similarly the abundance of aphid population was significantly lower in strip intercropping than wheat sole cropping at both growth stages of wheat noticed by Nassab et al. (2013) in his experiments in Iran. Comparable results were recorded by Levie et al. (2005) when about 45% of aphid population was reduced by the strip management. In our results garlic showed minimum population of aphids followed by alfalfa and berseem strip cropping. Similar findings of low level of aphid population in garlic strip was recorded by Zhou et al. (2013) in China who studied the effect of garlic as active repellent emitted plant or intercropping is beneficial in decreasing pest pressure.
    The results showed that aphid infestation started in the last week of January and gradually increased during the vegetative growth of wheat crop and reached its peak in second week of March at heading stage of crop when
    11.48 specimens were recorded per tiller. The population declined when the crop reached its maturity and there was no capturing after the first week of April. Similar observations to our results were noted by Xiong (1990), who observed that population of aphids increased with the development of wheat and peaked at the heading stage. Our findings are slightly different to Karimullah and Ahmad (1989) who noted a delay onset of aphid infestation during the first week of February. The difference might be due to the temperature fluctuation between the two locations as the temperature play an important role in insect population dynamics and densities (Bernal and González,
    1997; Leather et al., 1993). Maximum population of coccinelids and syrphid fly were recorded a week after the peak population of aphids during the third week of March. Different natural enemies syrphid fly, coccinellids, Chrysoperla carnea, Hymenopterous parasitoids were observed a week earlier ina different study where peak aphid population was in the mid of March (Saleem et al., 2009).
    Our results showed a positive correlation of predator
    species and aphid population on strip cropping suggested
    an indication of natural control of pest population. Current results  showed  that  the  predators’ population  was  not conspicuously different among different strip crops but the  numbers  were  significantly higher  than  the  wheat monoculture. Our results are in accordance with Munyuli et al. (2007), (2008) and Hongjiao et al. (2010) who observed higher species richness and diversity of predators i.e., ladybird beetles, syrphid fly, mantid, spiders, dragonfly, predatory bugs, ground beetles and mites in intercropping systems. This suggests that the intercropping changes the environmental condition, increase in biodiversity that make suitable niche for beneficial insects which promote biocontrol of pests (Andow, 1991; Stiling et al., 2003). The addition of second crop can produce a favourable microclimate for natural enemies (Thomas et al., 1992; Hossain et al., 2002), a place of alternative hosts or prey (Mathews et al., 2004) or a provision of plant-based foods (nectar, pollen and honeydew) (Wackers et al., 2007). The slight difference in coccinelid and syrphid fly population level among different strip cropping in the current study might be attributed to surrounding habitats, field margins, weedy strips, cultural practices and crop structure could affect the community composition. The presence of field boundaries, crop diversification as well as intercropping could enhance potential mechanism of field predators (Kromp,  1999)  and  may  increase  the  yield  of  main crop. Altieri et al. (1985) recorded a significantly higher population of Carabidae, Staphylinidae and spiders in the weedy and clover field than in the clean plots.
    CONCLUSION
    The intercropping systems increase the crop diversity in agro-ecosystems which ultimately affect the abundance of herbivore insects and their natural enemies that can be an important tool to reduce the abundance of aphids. Additionally along with intercropping the habitat type should be focused in the future studies because predators might respond more to the later which is related to the plant species.
    ACKNOWLEDGEMENT
    We are grateful to Dr. Faisal Hafeez, Assistant Entomologist, Entomological Research Institute, AARI, Faisalabad for assistance in field work and data collection. The research was funded and conducted in Ayub Agricultural Research Institute, Faisalabad, Pakistan.
     
    Statement of conflict of interest
    Authors have declared no conflict of interest.
    REFERENCES
    Altieri, M.A., Wilson, R.C. and Schmidt, L.L., 1985.
    The  effects  of  living  mulches  and  weed  cover on the dynamics of foliage- and soil-arthropod communities  in  three  crop  systems.  Crop  Prot.,
    4:        201-213.        https://doi.org/10.1016/0261-
    2194(85)90018-3
    Altieri,  M.A.  and  Rosset,  P.M.,  1995.  Agroecology and the conversion of large-scale conventional systems         to     sustainable     management.     Int. J. environ. Stud., 50: 165-185. https://doi. org/10.1080/00207239608711055
    Aheer, G.M., Munir, M. and Ali, A., 2006. Screening of wheat cultivar against aphids in ecological conditions of district Mandi Bahaudin. J. agric. Res., 44: 55-58.
    Andow,   D.A.,   1991.   Vegetational   diversity   and
    arthropod  population  response.  Annu.  Rev.  Ent.,
    36: 561-586. https://doi.org/10.1146/annurev. en.36.010191.003021
    Aslam, M., Razaq, M., Akhter, W., Faheem, M. and Ahmad, F., 2005. Effect of sowing date of wheat on aphid (Schizaphis gramium Rondani) population. Pak. Entomol., 27: 79-82.
    Bernal, J. and González, D., 1997. Reproduction of Diaeretiella rapae on Russian wheat aphid hosts at different temperatures. Ent. Exp. Appl., 82: 159-166. https://doi.org/10.1046/j.1570-7458.1997.00126.x
    Bowling,   R.W.,   Wlide,   G.E.   and   Margolies,   D.,

    1. Relative fitness of  greenbug  (Homoptera: Aphididae) biotypes E and I on Sorghum, Wheat, Rye and Barley. J. econ. Ent., 91: 219-231. https:// doi.org/10.1093/jee/91.5.1219

    Francis, C.A., 1989. Biological efficiencies in multiple cropping systems. Adv. Agron., 42: 1-42. https:// doi.org/10.1016/S0065-2113(08)60522-2
    Finch, S. and Collier, R.H., 2000. Host plant selection by insects- a theory based on appropriate/inappropriate landings by pest insects of cruciferous plants. Ent. Exp. Appl., 96: 91-102. https://doi.org/10.1046/ j.1570-7458.2000.00684.x
    Hongjiao, C., Minsheng, Y. and Cui, L., 2010. Effects of intercropping systems on community composition and diversity of predatory arthropods in vegetable fields. Acta  Ecol.  Sin.,  30:  190-195.  https://doi. org/10.1016/j.chnaes.2010.06.001
    Hossain, Z., Gurr, G.M., Wratten, S.D. and Raman, A.,

    1. Habitat manipulation in Lucerne (Medicago sativa L.): Arthropod population dynamics in harvested and ‘refuge’ crop strips. J. appl. Ecol.,

    39:      445-454.      https://doi.org/10.1046/j.1365-
    2664.2002.00729.x
    Irvin,  N.A.  and  Hoddle,  M.S.,  2007.  Evaluation  of floral resources for enhancement of fitness of Gonatocerus   ashmeadi,   an   egg   parasitoid   of the glassy-winged sharpshooter, Homalodisca vitripennis. Biol. Cont., 40: 80-88. https://doi. org/10.1016/j.biocontrol.2006.09.004
    Karimullah  and  Ahmad,  K.F.,  1989.  Incidence  of the cereal aphid Sitobion avenae (F) on different cultivars of wheat. Sarhad J. Agric., 5: 59-61.
    Khattak, G.S.S., Ashraf, M., Zamir, R. and Saeed, I.,

    1. High yielding desi chickpea (Cicer arietinum L.) variety “NIFA-2005”. Pak. J. Bot., 39: 93-102. Kromp, B.,   1999.   Carabid   beetles   in   sustainable agriculture:  a  review  on  pest  control  efficacy, cultivation   impacts   and   enhancement.   Agric. Ecosyst.    Environ.,    74:    187-228.    https://doi.

    org/10.1016/S0167-8809(99)00037-7
    Landise, D.A., Wratten, S.D. and Gurr, G.M., 2000.
    Habitat management to conserve natural enemies of arthropod pests in agriculture. Annu. Rev. Ent.,
    45: 175-201. https://doi.org/10.1146/annurev. ento.45.1.175
    Leather, S.R., Walters, K.F.A. and Bale, J.S., 1993. The ecology  of overwintering. Cambridge University Press, Cambridge, pp. 255. https://doi.org/10.1017/ CBO9780511525834
    Levie, A., Legrand, M.A., Dogot, P., Pels, C., Baret, P.V. and Hance, T., 2005. Mass releases of Aphidius rhopalosiphi   (Hymenoptera:   Aphidiinae),   and strip  management  to  control  of  wheat  aphids. Agric. Ecosyst. Environ., 105: 17-21. https://doi. org/10.1016/j.agee.2004.06.004
    Mathews, C.R., Bottrel, D.G. and Brown, M.W., 2004.
    Habitat manipulation of the apple orchard floor to increase ground-dwelling predators and predation of Cydia pomonella (L.) (Lepidoptera: Tortricidae). Biol. Cont., 30: 265-267. https://doi.org/10.1016/j. biocontrol.2003.11.006
    Munyuli, M.B.T., Luther, G.C. and Kyamanywa, S.,

    1. Effects of cowpea cropping systems and insecticides on arthropod  predators  in  Uganda and  Democratic  Republic  of  the  Congo.  Crop Prot., 26: 114-126. https://doi.org/10.1016/j. cropro.2006.04.010

    Munyuli, M.B.T., Kyamanywa, S. and Luther, G.C.,

    1. Effects of groundnut genotypes, cropping systems and insecticides on the abundance of native arthropod predators from Uganda and Democratic Republic of Congo. Bull. Insectol., 61: 11-19.

    Nassab, A.D.M.,  Mardfar,  R.A.  and  Raei, Y.,  2013.
    Effects    of    wheat-oilseed    rape    intercropping and fertilizer on Sitobion avenae and its natural enemies. Int. J. Biosci., 5: 43-50.
    Root, R.B., 1973. Organization of a plant-arthropod association in simple and diverse habitats: the fauna of collards (Brassica oleracea). Ecol. Monogr., 43:
    95-124. https://doi.org/10.2307/1942161
    Saleem, S., Ullah, F. and Ashfaq, M., 2009. Population dynamics and natural enemies of aphids on winter wheat crop. Pakistan J. Zool., 41: 505-513.
    Stiling,  P.,  Rossi,  A.M.  and  Cattell,  M.V.,  2003.
    Associational resistance mediated by natural enemies. Ecol. Ent., 28: 587-592. https://doi. org/10.1046/j.1365-2311.2003.00546.x
    Theunissen, J. and Den-Ouden, H., 1980. Effects of intercropping  with  Spergula  arvensis  on  pests of  Brussels  sprouts.  Ent.  Exp.  Appl.,  27:  260-

    1. https://doi.org/10.1111/j.1570-7458.1980. tb02973.x

    Thomas, M.B., Wratten, S.D. and Sotherton, N.W., 1992.
    Creation of island habitats in farmland to manipulate populations of beneficial arthropods: Predator densities and species composition. J. appl. Ecol.,
    29: 524-531. https://doi.org/10.2307/2404521
    Trenbath, B.R., 1993. Intercropping for management of pests and diseases. Field Crops Res., 34: 381-405. https://doi.org/10.1016/0378-4290(93)90123-5
    Tylianakis, J.M., Didham, R.K. and Wratten, S.D., 2004.
    Improved fitness of aphid parasitoids receiving resource subsidies. Ecology, 85: 658-666. https:// doi.org/10.1890/03-0222
     
    Vandermeer,  J.,  1989.  The  ecology  of  intercropping.
    Cambridge   University   Press,   Cambridge,   UK.
    https://doi.org/10.1017/CBO9780511623523
    Wackers, F.L., Romeis-Danvan, J. and Rijn, P., 2007.
    Nectar and pollen-feeding by insect herbivores and implications for tri-trophic interactions. Annu. Rev. Ent., 52: 301-323. https://doi.org/10.1146/annurev. ento.52.110405.091352
    Wratten, S.D., Berndt, L., Gurr, G., Tylianakis, J., Fernando, P. and Didham, R., 2002. Adding floral diversity to enhance parasitoid fitness and efficacy. In: Proceedings of the first international symposium on biological control of arthropods. Honolulu, Hawaii, pp. 211-213.
    Xiong, C.J., 1990. Study on the relationship between the occurrences of Rhopalosiphum padi (L) and the growing period of wheat. Insect Knowl., 27: 5-7.
    Yahya,  M.,  Saeed,  N.A.,  Nadeem,  S.,  Hamed,  M. and  Shokat,  S.,  2017.  Role  of  wheat  varieties and insecticide applications against aphids for better wheat crop harvest. Pakistan J. Zool., 49:
    2217-2225. http://dx.doi.org/10.17582/journal. pjz/2017.49.6.2217.2225
    Zhou, H.B., Lian, C.J., Yong, L., Francis, F., Haubruge, E.,  Bragard,  C.,  Jingrui,  S.  and  Dengfa,  C.,

    1. Influence of garlic intercropping or active emitted volatiles in releasers on aphid and related beneficial in wheat fields in China. J. Integ. Agric.,

    12:      467-473.      https://doi.org/10.1016/S2095-
    3119(13)60247-6