Reduction In Larval Population Research Articles

Characterization and field evaluation of tetrahedral and triangular nucleopolyhedrovirus of Spilosoma obliqua (SpobNPV) strain NBAIR1 against jute hairy caterpillar

Jute hairy caterpillar, Spilosoma (=Spilarctia) obliqua (Walker) (Arctiidae: Lepidoptera), is an irregular and polyphagous insect pest that occurs all over India. A severe natural viral epizootic was observed in the field population of S. obliqua in jute. The virus was characterized as Spilosoma obliqua nucleopolyhedrovirus (SpobNPV NBAIR1) based on morphological, biological, and molecular characterization. Under scanning and transmission electron microscopy (SEM and TEM), the occlusion bodies (OBs) of SpobNPV NBAIR1 appeared as both tetrahedral and triangular with the size ranged from 1.04-1.72 μm. The results on the bioassay studies revealed that the lowest LC50 value of 2.93 OBs/mm2 by leaf disc bioassay against the second instar S. obliqua showed its high virulence. The identity of SpobNPV was further confirmed by the amplification of polyhedrin gene (NCBI GenBank accession no. MK288145). Eleven species of lepidopteran insects, viz., Spodoptera litura, S. exigua, S. frugiperda, Helicoverpa armigera, Plutella xylostella, Amsacta albistriga, Maruca vitrata, Trichoplusia ni, Pieris brassicae, Agrotis ipsilon, and Bombyx mori, were not susceptible to the infection with SpobNPV NBAIR1. Field experiments on jute crop revealed 68.92, 78.59, and 93.16% reduction in larval population of S. obliqua at 3, 4, and 7 days post spray of SpobNPV NBAIR1 (1.5 × 1012 OBs/ha at 2 ml/l), respectively. The present study is a renewed effort in the management of S. obliqua by the new strain of SpobNPV NBAIR1.

Field evaluation of Bt 127 SC formulation against Spodoptera litura (F.) in soybean

Bt 127 SC formulation was field tested against Spodoptera litura larvae infesting soybean at Dharwad. Amongthe biopesticides, Bt 127 SC formulation @ 3 ml/l of water has proved to be significantly superior over commercial Bt formulation Delfin and untreated control and recorded lowest S. litura after both the sprays. There was a higher reduction in larval population on the seventh day after treatment both in Bt 127 SC formulation (0.54 l/mrl) and Bt commercial Delfin (0.75 l/mrl) treated plots as bacterial infection starts to manifest leading to high mortality of larva within 3-5 days after treatment. Soybean seed yield due to treatment by Bt 127 SC formulation (1733 kg/ha) and Bt commercial Delfin (1694 kg/ha) were on par but lower in comparison to the broad spectrum chemical insecticides that are effective against different orders of insects. There was negligible population of natural enemies in the plots before and after the treatments.

Restricting lepidopteran herbivory through trap cropping and bird perches in Egyptian clover (Trifolium alexandrinum L.)

The Egyptian clover L. is a winter season leguminous forage that supports a great diversity of insect pest populations in the Northern Indian Plains. In the context of evolving non-chemical approach for pest control, different trap crops viz. marigold, Tagetes erecta: chickpea, Cicer arietinum L.; and sunflower, Helianthus annuus, were planted as border rows around the clover plots to trap lepidopteran larvae. The push and pull strategy was further augmented by the help of neem seed kernel extract (NSKE) 3% spray on the main crop. Services of insectivorous birds were utilized through T-shaped bird perches for feeding on lepidopteran larvae. The lowest larval population of Helicoverpa armigera (2.29 individuals/m row length) was recorded in the plots with the trap crops such as marigold and bird perches, and those that received neem insecticidal sprays which indicated the decrease of larval population due to the repellant action of neem gave (75.8%) a reduction in larval population than the sole cropped plots, followed by chickpea (2.58 larvae; 72.8%) reduction in larval population and sunflower (3.53 larvae; 63%). Sunflower recorded the highest number of H. armigera population, at flowering stage of berseem which depicted the suitability of sunflower for the attractiveness of low number of the larvae (2.75 larvae/m row length) on berseem. The plots with berseem as a sole crop without any control measure exhibited significantly high H. armigera larvae (12.95 larvae per meter row length). The fecundity of pod borer on different trap crops revealed the highest fecundity population (7.25 larvae) of Helicoverpa on either chickpea or sunflower as trap crops. During the vegetative phase of berseem and the flowering stage of marigold and sunflower, these were recorded as favorable hosts. The highest green fodder yield (GFY; 1115 q/ha) was recorded in plots sown with marigold as the trap crop and with bird perches and in plots that received NSKE sprays as compared to sole cropped plots (700 q/ha). The data on seed yield also revealed superiority of berseem plots with sunflower, as a trap crop, and also a high parasitization by parasitoids.

Evaluation of insecticide formulations for management of fall armyworm, Spodoptera frugiperda (J.E. Smith) infesting Maize

Pooled data revealed that chlorantraniliprole 18.5% w/w SC @ 30 g a.i./ha was found most effective treatment which showed 70.12–89.47% reduction in larval population over untreated control during fortnight interval with 0.20–0.56 average larvae/plant and 68.25–71.46% reduction in damaged plants over untreated control due to larval infestation with 13.18–14.49% actual damaged plant in treatment plots. It also recorded the highest of 83.86 q/ha grain yield as against 61.61 q/ha in an untreated control. Flubendiamide 90 g/l + deltamethrin 60 SC @ 36+24 g a.i./ha was the second next best treatment in which 67.55–84.46% reduction in larval population with average 0.29–0.58 larvae/plant and 66.53–70.16% reduction in damaged plants with 13.49–15.14% actual damaged plants. 82.92 q/ha grain yield was recorded in this treatment. Flubendiamide 90 g/l + deltamethrin 60 SC @ 31.5+21 g a.i./ha was the third next best treatment with 63.85–83.12% reduction in larvae and 59.44–64.39% reduction in damaged plants with 81.64 q/ha grain yield. Foliar application of evaluated treatments was found safe to natural enemies of fall armyworm.

Cross-Ecosystem Effects of Agricultural Tile Drainage, Surface Runoff, and Selenium in the Prairie Pothole Region

The Prairie Pothole Region (PPR) of the United States and Canada is a vast network of wetlands that provide rich habitat for waterfowl and aquatic organisms. Much of the landscape surrounding these wetlands is dominated by agriculture, allowing for contaminants such as neonicotinoid insecticides and selenium to enter these water bodies following precipitation. We surveyed 18 wetlands in the PPR of South Dakota that were categorized as receiving surface runoff, tile drainage, or surrounded by grassland (control) for larval and adult insects and contaminant concentrations over two years. Selenium concentrations in the water, as well as in larval and adult insects were the biggest difference among our treatments, and concentrations of all three were approximately two times higher in tile drainage sites than in surface or control sites. For example, adult insect tissue concentrations were (μg/g, mean ± S.D.) 1.5 ± 1.3 in control sites, 1.7 ± 2.4 in surface runoff sites, and 4.4 ± 5.0 in tile drainage sites. Adult insects responded more sensitively to agricultural influences than larval insects, with up to 50% reductions in adult abundance in the tile drainage treatment even in the absence of larval population reductions. Reductions in adult populations in combination with the retention of selenium over metamorphosis indicate that agricultural influence in these wetlands may also affect the terrestrial ecosystem by reducing quantity and/or quality of insect prey for terrestrial consumers, such as waterfowl.

Management of cotton pink boll worm Pectinophora Gossypiella (Saunders) with Trichogramma bactrae and T. brasiliensis

Afield trial was conducted at ICAR-CICR research farm, Nagpur, during kharif 2016–2017 and 2017–2018 to evaluate the efficacy of egg parasitoid Trichogramma bactrae (Nagaraja) and T. brasiliensis (Ashmead) along with insecticides as check for management of cotton pink bollworm. In 2016–2017, results showed that the least number of exit holes were in T. brasiliensis treated plots followed by chemical treatment and T. bactrae. However, number of mines was the least in T. bactrae followed by chemical treatment and T. brasiliensis. The reduction in larval population over control was lowest in T. brasiliensis followed by T. bactrae and chemical control. During 2017–18 data revealed that the number of exit holes was the least in the plots sprayed with chemical insecticides and it was at par with T. bactrae. However, the least number of mines on epicarp was noticed in the plots imposed with T. bactrae followed by chemical insecticides. The significantly minimum per cent locule damage was noticed in the chemical treatment. Though the infestation of pink bollworm in the form of boll and locule damage was significantly low in insecticides treated plots it was comparable with T. bactrae and T. brasiliensis released plots.

Bio-efficacy of insecticides against invasive pest of Tomato pinworm, Tuta absoluta (Meyrick, 1917)

An attempt was made to evaluate the bio-efficacy of insecticide against Tuta absoluta under laboratory and field conditions. In laboratory bio-assay, 100% mortality was observed in case of chlorantraniliprole 18.5 SC @ 0.5 ml/l, spinosad 45 SC @ 0.4 ml/l and flubendiamide 480 SC @ 0.25 ml/l after 96 hrs of treatment. From the field evaluation of these newer insecticides against T. absoluta, maximum reduction in larval population was recorded in case of chlorantraniliprole 18.5 SC @ 40g a.i./ha (90.35%) followed by spinosad 45 SC @ 73g a.i./ha (87.58%) and flubendiamide 480 SC @ 48g a.i./ha (84.10%). Fruit yield was higher in plots treated with chlorantraniliprole 18.5 SC (22.6 t/ha) followed by spinosad 45 SC (22.2 t/ha) and flubendiamide 480 SC (21.4 t/ha) coupled with cost benefit ratio of 1: 2.10, 1: 1.95 and 1: 1.82, respectively.

Bio-efficacy of different novel insecticides and their interaction between numbers of sprays against diamondback moth (Plutella xylostella L.) infesting cabbage

The maximum reduction of diamondback moth larval population over control was observed in spinosad (58.82%) followed by lufenuron (55.18%). The moderately effective group of insecticides for reduction of larval population over control was fipronil (49.46%), emamectin benzoate (43.63%), chlorpyrifos (42.98%), novaluron (42.00%) and indoxacarb (39.34%). Azadirachtin (32.01%) found least effective. Two sprays (42.92%) were found more effective in controlling P. xylostella than single spray (47.93%).

Use of Bacillus thuringiensis israelensis in integrated vector control of Aedes sp. in Sri Lanka: a prospective controlled effectiveness study.

The annual incidence of dengue has been increasing over the last few years in Sri Lanka with seasonal epidemics. Biological control of the vector has not been part of the integrated vector control implemented by the public health authorities of Sri Lanka so far. This pilot study assessed the effectiveness of using Bacillus thuringiensis israelensis (Bti) spray to control the Aedes mosquito vector population density. Prospective controlled effectiveness study in three administrative divisions of Colombo. Study areas were selected from urban, semiurban and rural administrative divisions within the district, and they were compared with two matching controls from the same division. Test areas received three cycles of Bti spraying 1 month apart. Control areas were not sprayed with Bti. Ovitrap and larval indices were calculated at baseline and 2 weeks after each spray cycle. There was a significant improvement in the adult vector population (ovitrap index) in the test areas after three spray cycles, but this effect had disappeared after 8 weeks (no residual effect). There was no consistent positive impact on larval indices (premise, container and Breteau indices) after each spray cycle. Bti might have a moderate impact on adult vector populations mediated via transient reductions in larval populations. However, this effect is not sustained probably due to rapid re-infestation. Bti spray, if implemented, can only play a supplementary role to other vector control methods.

Efficacy and economics of different insecticides and bio-rational against Spodoptera litura (Fabr.) in Soybean

The efficacy and economics of different IGR’s, insecticides and bio-rational against Spodoptera litura (Fabr.) in soybean, revealed that at three days after first and second sprays the rynaxypyr (64.52%) and emamectin benzoate (58.84% reduction) respectively proved to be the most effective. At seven days more percent reduction in larval population found in chlorpyriphos (53.76 %) and quinalphos (58.59%) where as at 14 days the diflubenzuron (59.72%) and quinalphos (53.42%) found to be the more effective after first and second sprays respectively. Significantly higher seed yield was recorded in rynaxypyr 20 SC followed by spinosad 45SC. The highest gross income and net profit was recorded in rynaxypyr 20 SC.

Larvicidal Activity against Aedes aegypti and Chemical Characterization of the Inflorescences of Tagetes patula.

The crude acetone extract (CAE) of defatted inflorescences of Tagetes patula was partitioned into five semipurified fractions: n-hexane (HF), dichloromethane (DF), ethyl acetate (EAF), n-butanol (BF), and aqueous (AQF). BF was fractionated by reversed-phase polyamide column chromatography, obtaining 34 subfractions, which were subjected to HSCCC, where patuletin and patulitrin were isolated. CAE and the fractions BF, EAF, DF, and AQF were analyzed by LC-DAD-MS, and patuletin and patulitrin were determined as the major substances in EAF and BF, respectively. BF was also analyzed by HPLC and capillary electrophoresis (CE), and patulitrin was again determined to be the main substance in this fraction. CAE and the semipurified fractions (750, 500, 300, 100, and 50 mg/L) were assayed for larvicidal activity against Aedes aegypti, with mortality rate expressed as percentage. All fractions except AQF showed insecticidal activity after 24 h exposure of larvae to the highest concentration. However, EAF showed the highest activity with more than 50% reduction in larval population at 50 mg/L. The insecticidal activity observed with EAF might have been due to the higher concentration of patuletin present in this fraction.

Seasonal abundance and bio-efficacy of different insecticides against castor semilooper on castor

The present study was conducted at Chaudhary Charan Singh Haryana Agricultural University, Hisar, Regional Research Station, Bawal, Haryana (India). The larvae of castor semilooper remain active from 30th standard weeks to 47th standard weeks. The maximum larval population was recorded on the 32th standard week (6.1 larvae per plant) and 38th standard meteorological weeks (6.2 larvae per plant) due the high rainfall, 158 and 120 mm, during these weeks, respectively. Correlation indicates that minimum temperature, evening relative humidity and rainfall exhibited a positive relationship (r- 0.588, 0.577 and 0.650) with the larval population. Bio-efficacy of four insecticides with different doses was tested against A. janata infesting castor crop. One day after spraying thiodicarb @ 468 g proved best toxicant followed by thiodicarb @ 375 g, deltamethrin @ 11.2 g, deltamethrin @ 10.5 g, quinalphos @ 250 g, quinalphos @ 200 g, novaluron @ 100 g and novaluron @ 75 g. At three days after spraying, it was found that novaluron @ 100 g was the most effective followed by novaluron @ 75 g, thiodicarb @ 468 g, deltamethrin @ 11.2 g, thiodicarb @ 375 g, deltamethrin @ 10.5 g, quinalphos @ 250 g and quinalphos @ 200 g. At seven days after spraying novaluron @ 100 g proved to be best toxicant followed by novaluron @ 75 g, thiodicarb @ 468 g, thiodicarb @ 375 g, deltamethrin @ 11.2 g, deltamethrin @ 10.5 g, quinalphos @ 250 g and quinalphos @ 200 g. Novaluron 100 g was the overall most effective with 75.97 mean per cent reduction in larval population.

Effect of Different Insecticides against Insect Pests and Predators Complex on Brassica napus L., Under Field Conditions

The present study was conducted in the research area of Cotton Research Station, Multan during spring 2011. The main objective of the study was to evaluate the effect of different insecticides against mustard aphid (Lipaphis erysimi Kalt.), leaf miner (Phytomyza horticola Gour.), seven spotted lady beetle (Coccinella septumpunctata L.) and syrphid fly larvae under field conditions. Bifenthrin, diafentheuron, dimethoate and imidacloprid were the insecticides used and data was recorded before 1 day and after 1, 2, 3 and 7 days of spray application. Results on percent reduction indicated that bifenthrinwas most effective insecticide against L. erysimi and P. horticola. Bifenthrin caused 74.06% and 75.22% reduction in L. erysimi population and 85.13% and 84.02% reduction in P. horticola population after three and seven days of spraying. All insecticides were found toxic to the C. septumpunctata and syrphid fly larvae. However, Imidacloprid and dimethoate were found relatively safe as compared to other insecticides. Imidacloprid showed 57.34% reduction in C. septumpunctata population whereas dimethoate 52.77% reduction in larval population of syrphid flies after seven days of spray application. It is concluded that bifenthrin and imidacloprid can be used for the management of mustard insect pests because of their higher efficacy against aphids and leaf miners and less toxicity to beneficial insects.

Bio-efficacy of chemical Insecticides against Spotted Pod Borer,Maruca testulalis(Geyer) on Cowpea

Studies were conducted at Agricultural Research Farm, Banaras Hindu University, Varanasi during Kharif 2010 and 2011 to know the efficacy of some new molecule insecticides (azadirachtin, Bt, endosulfan 35% EC, thiodicarb 75% WP, spinosad 45% SC, lambda cyhalothrin 5% EC, indoxacarb 14.5% SC, profenophos 50% EC and acetamiprid 20% SP) against spotted pod borer, Maruca vitrata (Geyer) on mungbean. The spinosad 45% SC and indoxacarb 14.5% SC were the most effective treatments and significantly superior to other treatments with 80.7 and 79.2 per cent larval reduction over control. The least effective treatment was acetamiprid 20%SP, followed by azadirachtin with 38.8 and 44.9 per cent reduction in larval population over control. The maximum yield was recorded in treatment indoxacarb 14.5%SC (11.8q/ha) followed by spinosad 45%SC (11.1q/ha) which were at par with each other. While lowest yield was recorded in azadirachtin (9.7q/ha).

Isolation of Bacillus sphaericus screening larvicidal, fecundity and longevity effects on malaria vector Anopheles stephensi

In India, the most important diseases transmitting mosquitoes belong to the genera Anopheles, Culex, Aedes and Mansonia. The indiscriminate use of synthetic insecticides creates multifarious problems like environmental pollution, global warming, insecticide resistance and is hazardous to humans. In the present study, bacterial pesticide, Bacillus sphaericus a soil dwelling bacteria, isolated from the sludge samples collected from Bharathiar University, Coimbatore, India cultured with required substrates and used to control the malaria vector, Anopheles stephensi. Bioassay was conducted to test the larval toxicity, fecundity and mosquito longevity. LC50 and LC90 values were calculated for the larval instars of the malaria vector, A. stephensi. The fecundity and adult longevity were highly reduced after the treatment with B. sphaericus. Field trials were also conducted in different breeding sites of A. stephensi with different range of temperature and altitude. Percentage reduction of larval population was maximum (100%) at 96 h of treatment. Toxicity efficacy of B. sphaericus was varied according to the temperature and altitude of the study area. The bacterial pesticide B. sphaericusproved that it is an effective mosquito control agent and can be used for further integrated pest management programmes. Key words: Bacillus sphaericus, larval toxicity, lethal concentration, Anopheles stephensi, field studies.

Effect of biorational approaches for the management of blue butterfly (Lampides boeticusL.) in Pigeonpea

A filed experiment was conducted to determine the influence of intercropping and application of ecofriendly biopesticides on the management of blue butterfly, (L. boeticus.) Pigeonpea cv. Bahar intercropped with maize, pearl millet, sorghum, rice and black gram had significant influence on the reduction of larval population of [L. boeticus (L)] as compared with monocrop. The intercrops pigeonpea + pearl millet (2.86%), pigeonpea + sorghum (1.03%) and pigeonpea + black gram (0.62%) had lowest pod and grain damage by number and by weight basis, respectively. While, intercropping had no significant influence in reduction of pod and grain damage. The ecofriendly biopesticides i e. NSKE (5%), Nimbecidine (1%) and Bacillus thuringiensis kurstaki (1.5%) sprayed once and twice (first at flowering and pod formation stage and second after 20 days) were found superior over one spray of biopesticides in reducing the larval population, pod damage, grain damage and grain weight loss and their mean values varied from 0.21 to 0.39 larva plant-1, 1.75 to 4.08%, 0.53 to 1.41% and 0.37 to 0.87%, respectively. However, the plots devoid of any biopesticidal treatment had maximum larval infestation (0.70 larva plant-1), pod damage (4.62%), grain damage (1.82%) and grain weight loss (1.12%).

Isolation, Identification, Bioassay and Field Evaluation of Native Bacillus thuringiensis Strains against Spodoptera litura (Fabricius) in Groundnut (Arachis Hypogaea)

A field experiment in a randomized block design was conducted to evaluate 28 Bacillus thuringiensis isolates along with a reference strain HD1 and untreated control against Spodoptera litura in groundnut. Larval population of S. litura per meter row at 3 days after spray (DAS) was lowest (9.0) in plot treated with Bt strain 341. Mean per cent reduction of larval population over pretreatment was maximum (56.83%) in HD1 reference strain and it was followed by the Bt strain 375 (51.45%). Minimum larval population of S. litura (7.0) was observed at 5DAS in HD1 and 375 Bt strains. Mean per cent reduction of larvae over pretreatment was maximum (68.32%) in HD1 reference strain followed by Bt strain 21 (57.27%). Minimum larval population of S. litura (5.0) was recorded at 7DAS in plot treated with Bt strains HD1, 375 and 416. Mean per cent reduction of larvae over pretreatment was highest (77.02%) in HD1 reference strain followed by Bt strain 375 (74.47%). Per cent leaf damage due to S. litura was minimum (12.83%) in plots treated with HD1 reference strain followed by strain 375 (14.06%). Maximum pod yield (3900 kg/ha) was recorded in the plots treated with HD1 reference strain followed by Bt strain 375 (3870.0kg/ha).

Evaluation of Certain Botanical Preparations against African Bollworm, Helicoverpa armigera Hubner (Lepidoptera: noctuidae) and Non Target Organisms in Chickpea, Cicer arietinum L

Aqueous extract of individual and mixed form of Azadirachta indica A. Juss seeds kernel and leaves of Milletia ferruginea, Hochst and Croton macrostachyus Hochst was tested against African bollworm, Helicoverpa armigera Hubner. Antifeedant activity of selected plant extract was tested at 1%, 2.5%, 5% and 10% concentration against 4th instar larvae of H. armigera in the laboratory and 5% concentration was tested under field condition. All the tested plant extract showed 100% protection at 5% and 10% concentration. Among the various botanical treatment Neem Seed Kernel Extract (NSKE) and NSKE+BLE (Birbira Leaves Extract) was effective at 2.5% concentration with minimum pod damage. In the field observation among the botanicals, reduction of larval population in the treatment of NSKE, BLE and NSKE+BLE was statistically not significant (p>0.05; LSD). The lowest percentage pod damage (0.45%) was observed in Diazinon 60% EC treated plot followed by NSKE treated plot (3.90%) after second spray. The highest mean yield was obtained from NSKE treated plot (781 g) followed by Diazinon 60% EC treated plot (719.33 g), NSKE+BLE (656.67 g) and BLE treated plot (653.33 g). Five days after second treatment there was a significant difference in the mean number of ants between NSKE+BLE, control and other treatments. The highest mean number of spiders was observed in control plot (3.6) and lowest (0.3) was in plot treated with Diazinon 60% EC. The reduction of lady bird beetle population among the botanicals treated plots was statistically not significant (p>0.05; LSD). The mean number of wasp population was the highest in control plot (3.3) and there was no wasp observed in Diazinon 60% EC treated plot. In conclusion, even though Diazinon 60% EC was found to be effective by considering the interaction of beneficial in the field botanical preparations are much better particularly NSKE and also suitable to spray under rain fed condition to protect the crop by small farming communities.

Assessing Lepidopteran Abundance and Crop Injury in Soybean Lines Exhibiting a Synthetic Bacillus thuringiensis cry1 A Gene

Transgenic lines of soybean, Glycine max (L.) Merrill, expressing a synthetic cry 1A gene from Bacillus thuringiensis Berliner (Bt), were evaluated in replicated field trials in 1999–2002 for suppression of lepidopteran pests and the resultant crop injury. Velvetbean caterpillar, Anticarsia gemmatalis Hübner, soybean looper, Pseudoplusia includens (Walker), and green cloverworm, Hypena scabra (F.), population densities were essentially absent throughout the growing season in each year of the study in each of the Bt lines evaluated compared with moderate (5–10 larvae per row-m) to heavy (15–20 larvae per row-m) populations in the isogenic and parental lines serving as soybean controls. Significant A. gemmatalis larval population reductions were observed in the Bt entries compared with the nonBt entries in each year of this study. The P. includens larval densities were significantly lower in Bt entries in the 3 yrs of this study when population densities were abundant, whereas H. scabra were lower in the Bt lines in the 2 yrs of this study when this species was present. Cumulative defoliation in nonBt soybean entries exceeded 95% in some years compared with 0.0–1.6% in the transgenic lines containing Bt. Yields of the transgenic soybean lines were equal to or higher than the non Bt lines examined in each year of this study. It appears that these Bt transgenic soybeans provide superior season-long control of the common lepidopteran pests on soybeans in the southern U.S., resulting in reduced defoliation levels and potentially higher yields compared with equivalent cultivars that lack the Bt trait.

Role of Avian Community in Reduction of <i>Spodoptera</i> Pest Population in Sugar Beet at Pune

Experiments were conducted at Vasantdada Sugar Institute, Pune in a RBD with three replications during 2005 to 2007 in sugar beet (var. posada) for control of Spodoptera litura Fab. The ornithological studies had shown the major avian community, Acridotheres tristis (Linnaeus), Passer domesticus (Linnaeus), Vanellus indicus (Boddaert), Corvus splendens (Vieillot), Centropus sinensis (Stephens), Pycnonotus cafer (Linnaeus), Eudynamys scolopacea (Linnaeus), with a relative abundance of 14.33, 13.26, 11.46, 5.73, 3.87, 3.54, and 2.79%, respectively.The reduction in mean S. litura population due to the pick up of the larvae by birds during three crop seasons ranged from 33.90 to 69.47%. Installation of minimum 15 bird perches/ha in 60 days after sugar beet sowing noticed effective considering the number of birds sittings (130.66/day), reduction in larval population of S. litura (39.99%), and root yield (71.36 ton/ha).Keywords: Sugar beet, Spodoptera, avian community, yield.doi: 10.3126/on.v6i1.1650Our Nature (2008)6:19-25