Pest Management Techniques Research Articles

Increasing predation risk with light reduces speed, exploration and visit duration of invasive ship rats (Rattus rattus)

Exploiting predation cues to deter pests remains an untapped management tool for conservationists. We examined foraging and movement patterns of 20 wild ship rats (Rattus rattus) within a large, outdoor ‘U maze’ that was either illuminated or dark to assess if light (an indirect predation cue) could deter rodents from ecologically vulnerable locations. Light did not alter rats’ foraging behaviour (latency to approach seed tray, visits to seed tray, time per visit to seed tray, total foraging duration, foraging rate) within the experimental resource patch but three of seven movement behaviours were significantly impaired (53% fewer visits to the maze, 70% less exploration within the maze, 40% slower movement within the maze). The total time males spent exposed to illumination also declined by 45 minutes per night, unlike females. Individual visits tended to be longer under illumination, but the latency to visit and the latency to cross through the U maze were unaffected by illumination. Elevating predation risk with illumination may be a useful pest management technique for reducing ship rat activity, particularly in island ecosystems where controlling mammalian predators is paramount to preserving biodiversity.

The impact of fungicide treatment and Integrated Pest Management on barley yields: Analysis of a long term field trials database

Abstract This paper assesses potential for Integrated Pest Management (IPM) techniques to reduce the need for fungicide use without negatively impacting yields. The impacts of three disease management practices of relevance to broad acre crops –disease resistance, forecasting disease pressure, and fungicide use – were analysed to determine impact on yield using a long-term field trials database of Scottish spring barley, with information from experiments across the country regarding yield, disease levels, and fungicide treatment. Due to changes in data collection practices, data from 1996 to 2010 were only available at trial level, while data from 2011 to 2014 were available at plot level. For this reason, data from 1996 to 2014 were analysed using regression models, while a subset of farmer relevant varieties was taken from the 2011–2014 data, and analysed using ANOVA, to provide additional information of particular relevance to current farm practice. While fungicide use reduced disease severity in 51.4%of a farmer-relevant subset of trials run 2011–2014, and yields were decreased by 0.62 t/ha on average, this was not statistically significant in 65% of trials. Fungicide use had only a minor impact on profit in these trials, with an average increase of 4.4% for malting and 4.7% for feed varieties, based on fungicide cost and yield difference; potential savings such as reduced machinery costs were not considered, as these may vary widely. Likewise, the1996–2014 database showed an average yield increase of 0.74 t/ha due to fungicide use, across a wide range of years, sites, varieties, and climatic conditions. A regression model was developed to assess key IPM and site factors which influenced the difference between treated and untreated yields across this 18-year period. Disease resistance, season rainfall, and combined disease severity of the three fungal diseases were found to be significant factors in the model. Sowing only highly resistant varieties and, as technology improves, forecasting disease pressure based on anticipated weather would help to reduce and optimise fungicide use.

Fluctuation of Insect Population on Rice Field in Pangkalan Sub-district Karawang Regency: Indicator for Environmental Health

Pangkalan Sub-district is a forest edge area in Karawang that is rich in flora and fauna that has not been much identified. Because of its unique location that is bordered by primary forest, agricultural ecosystems in the area will not be separated from the influence of the surrounding forest. So, it is necessary to know more about the diversity and abundance of insects in the wetland rice ecosystems.The research was conducted in Pangkalan sub-district, Karawang regency. The size of each plot was 5 x 5 m (25 m2) and each treatment was repeated five times. Treatments carried out with integrated pest management (IPM), chemical pest management techniques (P-K), and Mixed Pest Management (P-C). Insect retrieval technique using sweep net method, yellow pan trap, and direct observation. The abundance of arthropod species found in 12 Orders consist of: Thysanoptera Order (2.4%), Orthoptera (0.5%), Odonata (1.4%), Mantodea (0%), Lepidoptera (8.7%), Hymenoptera (2.4%), Hemiptera (61.8%), Diptera (2.4%), Derma ptera (3.6%), Coleoptera (8.3%), Architaenioglossa (0.5%), and Aranea (8.0%). Based on the species richness, it was found that the orders of Diptera (25 species), Coleoptera (19 species), and Hymenoptera (18 species) showed higher numbers than other orders. The H 'diversity index in this study ranged from 1.99 to 2.45, the D index ranged from 0.73 to 0.88, and the E index ranged from 0.5 to 0.7. Overall the P-K plots showed a lower population abundance compared to IPM and P-C plots. Intense and scheduled spraying of insecticides on P-K plots causes a lower population abundance, which makes the diversity become low. Keywords: Rice pests, diversity of insects, natural enemies, pesticides, integrated pest control (IPM)

Deployment of the sex pheromone of Pseudococcus calceolariae (Hemiptera: Pseudococcidae) as a potential new tool for mass trapping in citrus in South Australia

ABSTRACTMealybugs damage a variety of crops worldwide, vectoring viruses and causing problems from sooty mould. The identification of the citrophilous mealybug (Pseudococcus calceolariae, CMB) female sex pheromone has created opportunities for its use as a pest management tool that could potentially result in a reduced reliance on insecticides. Mass trapping is a pest management technique that uses baited traps to decrease pest insect densities. To assess the efficacy of the P. calceolariae sex pheromone as a mass trapping tool, a field trial was conducted in citrus in South Australia. The vertical distribution of CMB within the citrus was examined. Male flight activity was monitored using red delta traps in the centre of six 1-ha ‘plots’, after which time half the plots had 306 tent traps containing synthetic CMB pheromone lures deployed (mass traps). Six weeks after the application of mass trapping we observed a 90% lower catch in treated plots compared to catches in control plots. There were strong spatial patterns in trap catch with the Edge to Centre ratio being 3.6:1. P. calceolariae male flight activity showed peaks in October and May. Mass trapping showed promise as an effective management technique for P. calceolariae. Challenges such as male multiple mating and mealybug airborne dispersal still need to be overcome before mass trapping can be used as a reliable management technique.

Geographical Distribution of South American Tomato Leaf Miner Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae) in Nepal

South American tomato leaf miner, Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae) is an invasive insect pest of tomato (Lycopersicon esculentum Miller) both in field and controlled environment conditions. T. absoluta is native to South America, it was detected first time in Nepal from Kathmandu during May, 2016. Survey was conducted at 46 locations of 31 districts in terai and mid hills of Nepal during February to June 2018. T. absoluta was detected from 45 locations of 30 districts surveyed. T. absoluta which was detected from Kathmandu, Lalitpur, Bhaktapur, Kavre and Dhading districts in 2016 has now been spread into 33 districts across the Nepal. Apart from 33 districts T. absoluta might be present in other districts which were not surveyed during the study. Farmers generally manage T. absoluta through indiscriminate use of chemical pesticides. So, extensive research is needed in future to develop integrated pest management technique which is suitable and sustainable for its management in Nepalese context.

Pesticide Use in Northern Ireland’s Arable Crops from 1992–2016 and Implications for Future Policy Development

Since the 1960s, the objective for the United Kingdom (UK) government policy and legislation on crop protection practices has been to minimise the impact of pesticide use in agriculture and horticulture to the wider environment. Subsequent European Union (EU) policy and legislation have also targeted this objective through a demanding approvals process, competency tests for users, maximum residue limits, regular post-registration monitoring and the promotion of integrated pest and disease management techniques. However, none of this substantive regulation refers to target reduction levels for pesticide use. Since 1992, the number of arable farms in Northern Ireland has decreased by 61% with a consequent reduction of 34% in the area of arable crops grown. Despite this reduction in area of arable crops grown, the area treated by the major pesticide groups increased by 49% due to intensification, but the weight of major pesticides applied to arable crops decreased by 37%. However, the intensity of application measured by the total quantity of all pesticides applied to the basic area of arable crops treated remained relatively constant at approximately 3.2 kg/ha. Pesticide usage trends and reduction policies in other geographic regions are also discussed for comparative purposes.

Dietary methoprene supplement promotes early sexual maturation of male Queensland fruit fly Bactrocera tryoni

Sterile insect technique (SIT) is an environmentally benign pest management technique that relies on released sterile male insects mating with, and curtailing reproduction of, wild females. However, for species with high mortality rates and long adult maturation phases, a large proportion of the released insects can die before maturing and so fail to contribute to SIT. To counter this problem, inclusion of yeast hydrolysate in pre-release diets and treatment of pupae or adults with methoprene, a juvenile hormone analogue, have been investigated as means of accelerating development of some fruit flies, including Queensland fruit fly, Bactrocera tryoni (Froggatt) (‘Q-fly’). Methoprene has most often been administered topically in acetone solution, which is toxic, flammable, and impractical for operational settings. As a practical alternative, we incorporated methoprene (0, 0.05, 0.1, and 0.5%) into Q-fly adult diet of sugar only or sugar mixed with yeast hydrolysate for 2 days, and then provided sugar only for the rest of the trial period. Mating performance of males and females was tested from 4 to 30 days of age. Flies provided sugar mixed with yeast hydrolysate had increased mating propensity in comparison with flies that were provided sugar only. At all ages and for both diets, all methoprene doses increased male mating probability. Methoprene treatment did not affect copula latency of males that received yeast hydrolysate, but males that received only sugar mated earlier if they had received 0.05% methoprene. Methoprene treatment of males was also associated with longer copulations, which may affect fertility of females that later remate. Females differed from males in that methoprene treatment did not significantly affect mating probability or latency, but resembled males in that methoprene treatment resulted in longer copulations. Sex differences in response to methoprene may lead to male-biased operational sex ratio when bisex Q-fly strains are used in SIT. Yeast hydrolysate increased longevity of both males and females, but methoprene treatment did not affect longevity. Overall, findings of the present study indicate that Q-fly sexual maturation can be accelerated, and SIT might hence be enhanced, by incorporation of methoprene and yeast hydrolysate in pre-release diet.

CHEMICAL CONTROL OF RODENTS IN ANIMAL FARMS (IZZAB) IN QATAR STATE

The aim of this study is to develop a control program for rodents in animal farms (Izzab) in Qatar. The preliminary baseline survey for rodent-infested Izzab revealed that 1506 Izzab out of 1814 was infested (83%). The overall percentage reduction in the rodent-infested Izzab after 6 months of the control programme was 77%. Towards the end of the control programme, a special strategy was adopted to control rodents in 327 Izzab in which rodents’ activity was still observed. A 75% reduction was attained in these Izzab at the end of the control programme. The overall reduction in the infested Izzab was 94% at the end of the control programme. The most predominant rodent species found in Izzab is the Norway rat Rattus norvegicus, making burrows inside and outside Izzab buildings. Fewer incidences were noted for the House mouse Mus musculus associated with Izzab buildings. It is recommended that bait consumption and rodents’ activity are to be monitored regularly so as to locate the farms that are still having problems and to detect any new foci or outbreaks. Implementing of Integrated Pest Management (IPM) technique is also highly recommended.

Nighttime Applications of Two Formulations of Pyrethroids are Effective Against Diurnal Aedes albopictus.

The successful control of Aedes albopictus requires a multifaceted approach using a variety of integrated pest management techniques. Because this species is diurnal, nighttime ultra-low volume adulticide applications seem likely to miss resting mosquitoes and, therefore, are often met with skepticism. The goal of this study was to compare the efficacy of nighttime applications of pyrethroids with and without prallethrin to control caged and field populations of Ae. albopictus. During August and September of 2015, 2 adulticide applications were performed, treating 4 urban sites in the city of Trenton. We compared Anvil®, which contains sumithrin and piperonyl butoxide (PBO), to Duet™, which contains sumithrin, prallethrin, and PBO. Because prallethrin excites resting mosquitoes to flight, we hypothesized that Duet would kill more mosquitoes, especially those resting in cryptic harborages. Comparing pretreatment and posttreatment adult mosquito numbers, Biogents Sentinel trap collections revealed twice as many mosquitoes were killed by Duet than by Anvil. For caged Ae. albopictus, both products performed comparably, with Duet achieving a slightly higher mortality in front yards and Anvil achieving a slightly higher mortality in backyards. It is clear that nighttime adulticide applications are effective against Ae. albopictus, and the need to continue efficacy data collection is important because adulticiding is a key component of disease control response.

Response of Soil Nematodes Under Different Pest Management Practices: A Field Experimental Approach in Tomato (Lycopersicon Esculentum L.) Growing Agro-Ecosystem

The need of eco-friendly pest management practice is important to maintain soil biodiversity and sustainable agriculture. Therefore rigorous investigation is needed for the environmentally friendly pest management techniques worldwide including Nepalese Tomato growing farms. We conducted field experiment to monitor the diversity and community structure of soil nematodes under different pest management practices in Tomato (Lycopersicon esculentum) growing farm. The study was conducted during summer and winter season in 2015 in Tokha area of Northern part of Kathmandu valley. The field was designed as Urine mixture plot (MP), Pesticides plot (PP), Botanicals plots (BP) and Control plot (CP). Our result indicated the variation of abundance and diversity of nemato-fauna with treatment plots and seasons. The generic diversity and community composition of nematodes in Urine mixture treating plots (MP) was increased significantly whereas decreased in pesticide applying plot (PP). The F/B ratio was significantly affected with treatment system rather than seasonality and found to be increased in pesticides applying plots. The abundance samples of nematodes genera were well separated in our discriminate ordination. We highlight the need of further exploration on the diversity and community dynamics of soil nematodes under different pest management practices in Tomato growing Nepalese agro-farms for sustainable soil ecosystem service. Journal of Institute of Science and Technology Volume 22, Issue 2, January 2018, Page: 45-55

The biochemical correlation between the epicuticular wax of upland cotton (Gossypium hirsutum L.) and the wax of different mealybug species

The study aimed to find the possible differences, existing between the cuticular waxes of cotton and mealybug insects, using advanced analytical studies. The biochemical composition of the leaf wax of upland cotton (Gossypium hirsutum L.) and the cuticular wax of the different mealybug species, including Phenacoccus solenopsis Tinsley, Ferrisia virgata Cockerell, Paracoccus marginatus Williams and Granara de Willink, and Drosicha mangiferae Green were analyzed in detail by Gas Chromatography-Mass Spectrometry (GC-MS). The results clearly confirmed that the cotton wax is dominated by the six-carbon alkanes, while the mealybug wax is a mixture of both the five-carbon alkanes and the six-carbon alkanes. Apart from these differences, the common hydrocarbons such as hexadecane, icosane, and heneicosane, the uncommon hydrocarbons such as ethane, cyclobutanone, decane, and cyclododecane, the species-specific compounds of mealybugs such as myristyl alcohol, quinoline, hexacosane, and pentacosane were also identified and their retention times (RT) were listed out in detail. The outcome of this study will be useful to develop pest management techniques targeting the waxy cuticle of mealybugs without obstructing the normal physiology and growth of the cotton crop.

<p class="HeadingRunIn"><strong>Urban Nature Gardens at the Natural History Museum of Los Angeles County attract “wildlife spectacle” of insect pollinators</strong></p>

The newly-constructed Nature Gardens at the Natural History Museum of Los Angeles County (California, USA) were purposefully built to attract wildlife. In this study we wanted to find out to what extent this manufactured environment is successful in attracting native insect fauna to the urban core of the city when compared to the surrounding neighborhoods or natural areas on the periphery of Los Angeles. To determine this, a one-year Malaise trap catch from the Nature Gardens was compared with samples from four neighboring sites within a five-kilometer radius, as well as a site adjacent to natural habitat located sixteen kilometers away. Our analysis focused on the diversity and abundance of three pollinator groups: bees, flower flies and butterflies contrasted with a single non-pollinator group: scuttle flies. Our findings show that the Nature Gardens support greater abundance and diversity than any of the nearby sites or the natural site for all pollinator taxa examined. In contrast, the natural site supported much higher abundance and diversity of the non-pollinator scuttle flies when compared to the Nature Gardens. Calculated evenness of all taxa was lower in the Nature Gardens than at the natural site and Shannon Diversity indices were highest in the Nature Gardens for flower flies and butterflies, but lower in the Nature Gardens than at the natural site for bees and scuttle flies. These results indicate that biodiversity in an urban environment can be selectively manipulated through management of green spaces, but may not duplicate the communities found in natural spaces. Rather, targeted management (through plantings, ground cover and other substrates, watering, pest management techniques, etc.) can increase fauna predictively to create a “wildlife spectacle” of charismatic microfauna.

Improving Navel orange (Citrus sinensis L) productivity in Delta Region, Egypt

The objective of this work presents general information about the Washington Navel sweet orange cultivar (Citrus sinensis L.) productivity in Delta region, Egypt, over the next few years, focusing on increasing total yield and enhancement fruit quality by following good agricultural practices, and increasing alertness among growers of the need for implement fruit quality to compete in the global market. Some of the practices include usingproper fertilizers, irrigation technique, pruning, integrated pest management and harvest technique.

Efikasi Ekstrak Buah Makasar (Bruceae Javanica L. merr.) untuk Mengendalikan Larva Spodoptera litura f.

The S. litura larvae often cause damage to the leaves of legume, corn, rice, onion, lettuce, mustard, cotton, tobacco, sugar cane, and banana leaves. In general, people use synthetic insecticides to control it, although it is proven to cause environmental pollution, the emergence of resistance and pest resurgence. To reduce these impacts, it is necessary to look for alternative control methods that are safe, effective, and compatible with Integrated Pest Management techniques. Alternative controls that meet these criteria include botanical insecticides, because they are more specific, do not pollute the environment, are easily degraded in nature, and do not quickly cause resistance. Simaroubaceae family plants contain pesticides with active quasinoid compounds. One species of Simaroubaceae is Brucea javanica (L.) Merr. which is known as the Makasar fruit which contains alkaloid compounds, quassinoids (Bruceantine, bruceantinol, brusatol, bruceine), polyphenols, tannins and essential oils. Four quasinoid compounds from Samadera indica namely indakuasin, samaderin A, B, and C are inhibiting food, slowing development, and causing pupa death from Spodoptera litura caterpillar F. To control S. litura larvae in various plants and further research and development needs, then conducted a study Effication of Macassar Fruit Extracts (Bruceae javanicaL. Merr.) to Control S. litura Larvae. The study used a randomized design with seven treatments and four replications. The seven treatments are fresh makasar fruit boiled extract, dry skinless makasar fruit boiled extract, dry skinned makasar fruit boiled extract, fresh makasar fruit fermented extract, skinless dry makasar fruit fermented extract, makasar dry skinned fruit fermented extract, and synthetic Lamda fruit insecticide cyhalothrin (as a control) with four replications. Fermentation extract is quite effective and can cause mortality of 61.7% to 63.3%. Boiled extract is less effective than boiled extract, which is only capable of causing 40.0% to 41.6% mortality. Keywords: macasar fruit, S. litura, vegetable insecticides

A Review of Bird Deterrents Used in Agriculture

Author(s): Rivadeneira, Paula; Kross, Sara; Navarro-Gonzalez, Nora; Jay-Russell, Michele | Abstract: Animal intrusion causes significant agricultural losses each year. Wild and domestic animals destroy crops by eating and trampling them, and can pose food safety risks due to the deposition of feces on or near the crops. Birds are one of the most challenging animals to keep out of agricultural fields. Growers try countless methods to deter them, including visual, auditory, tactile, and olfactory means. While some of these methods work some of the time, none provide stand-alone protection all the time. Recently there has been interest in developing technology-based solutions to deter nuisance birds in agricultural settings, while others are exploring more natural methods, including falconry. We provide a general overview of bird deterrent methods that are currently in use in agricultural settings, and explore options for novel methods. We found that very few independent scientific studies have been conducted to assess the efficacy of most bird deterrent methods. Ultimately, a multi-tiered approach using integrated pest management techniques will likely be most useful as it can be tailored to meet the needs of individual farmers.

The impact of tillage regime and row cover use on insect pests and yield in organic cucurbit production

AbstractControl of cucurbit pests, such as striped cucumber beetle (Acalymma vittatum), spotted cucumber beetle (Diabrotica undecimpunctata howardi) and squash bug (Anasa tristis), in organic systems is difficult due to a lack of effective insecticide options. This has led to the development of many integrated pest management techniques, such as use of row covers, crop rotation and cover crops. This study explored the novel use of strip tillage and row covers to reduce pest pressure in summer squash (Cucurbita pepe) and muskmelon (Cucumis melo) production systems. Results showed that although strip tillage reduced striped cucumber beetle and squash bug numbers, there was a yield reduction in both crops compared with the plasticulture system. Row cover increased marketable yield in both systems, with the highest yield being in the plasticulture system. Unmarketable fruit directly attributed to insect damage was higher in the plasticulture systems, but was not significantly different when compared with the strip tillage system. Although there are many documented positive attributes of strip tillage, results from this study indicate that a combination of plasticulture and row cover may be a superior system for organic cucurbit production.

Farmers' Knowledge of Integrated Pest Management Techniques of Sugar Beet Crop in Some Villages in El - Minia Governorate

Farmers' Knowledge of Integrated Pest Management Techniques of Sugar Beet Crop in Some Villages in El - Minia Governorate

Effects of strip-tilled cover cropping on the population density of thrips and predatory insects in a cucurbit agroecosystem

Strip-till cover cropping provides a structurally complex habitat (both diverse above ground vegetation and modified soil surface environment) in subsequent crops, which can contribute to suppressing herbivores in the cash crop, through either enhancing conservation biological control or altering herbivore behavior to the complex habitat. Two field trials (spring and autumn) were conducted to examine effects of strip-tilled cover crops (sunn hemp and marigold) on population densities of thrips (primarily, Frankliniella occidentalis and Thrips palmi) and generalist predators (Orius spp. and ground beetles, Aephnidius spp.) in cucurbit plantings. The results showed that strip-tilled cover crop treatments reduced thrips densities on cucurbit crops compared to the conventional monoculture. The strip-tilled treatments suppressed thrips densities more consistently in the autumn than in the spring trial. The reduced densities of thrips in strip-tilled cover crop plots were not attributable to the enhanced activity of predatory insects, but were most likely due to the disruption of host locating ability of thrips. Our study showed that the strip-till cover cropping could be an effective pest management technique for sustainable cucurbit production.

Regulation status of quarantine pests of rice seeds in the economic community of west African states (ECOWAS)

The ever growing international trade has limited efforts towards the prevention of introduction, spread and establishment of invasive organisms. Non-native pests can cause severe loss of production and lead to restriction in exchange of genetic materials and seed marketing across regions. Regulating pests’ movement through quarantine measures and establishment of regional boards has been identified as a way to deal with introduction and expansion of invasive organisms. This review analyzes the different pest regulations in the West African sub-region with a specific focus on the implementation of quarantine measures in rice as a case study. The various regulations related to seed production, certification and marketing, and quarantine regulations in West Africa were analyzed and their enforcement and performance were assessed through comparison to international standards, especially the International Plant Protection Convention (IPPC). Although a regional regulation on seeds and phytosanitary measures has been elaborated, ECOWAS countries are still enforcing their national phytosanitary legislations, which are nearly the same in all West African countries - they all aim at ensuring plant health by applying preventive and curative measures to prevent the introduction and spread of pests in their territory by controlling the import and export of plant materials and disseminating appropriate pest management techniques to boost agricultural production. Most ECOWAS countries are yet to submit their phytosanitary legislation to IPPC to comply with Article VII.2i of the endorsed convention. In addition, the entry points are not well defined and provided to the IPPC according to the Article VII.2d of the convention. When the quarantine list is available, the organisms regulated for each crop species are not stated, posing a real problem not only for rice genetic resource exchanges for research purposes but also for rice seed trade. Efforts and resources should be devoted by each country to research on pests and regulatory mechanisms in order to define, among others, pest status in the region, and to update regularly the quarantine pests list in the West African region. Key words : Regulatory measures, quarantine pest, rice seed, harmonization, ECOWAS, IPPC

Keanekaragaman spesies parasitoid telur Helicoverpa armigera (Hübner) pada sistem tanam monokultur dan polikultur kapas

Polyculture system is one of techniques in pest management. In Indonesia, cotton is always intercropped with second food crops such as maize, soybean, mungbean or peanut. This research was aimed to evaluate the effect of culture system, i.e. cotton monoculture vs. cotton intercropped with soybean on the increase of species diversity of H. armigera egg parasitoids and the parasitoid contribution to mortality of H. armigera. The research was arranged in a split plot design with two main factors: three cotton varieties with three levels of trichome density (Tamcot SP 37, Kanesia 8 and LRA 5166) and the subplots were two cultivation systems (cotton monoculture and polyculture), with three replicates. Observations were made by collecting H. armigera eggs on population of first generation (45 days after planting) and second generation (75 DAP). The results showed that on cotton polyculture the egg parasitoid complex which consisted of Trichogramma spp. and Trichogrammatoidea spp. was higher than that in cotton monoculture and so was the egg parasitism level. The increase of egg parasitism was 24% in the first generation and 15% in the second generation. Parasitoid species found belonged to the genera Trichogramma and Trichogrammatoidea. In the parasitoid complex, Trichogrammatoidea armigera was dominant on the first generation and Trichogramma chilotraeae on the second. The domination succession could be as a result of the higher host-searching capacity of T. chilotraeae than that of T. armigera.