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M. Sc. Dissertations

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2013 - 20143
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Subject: Agricultural Entomology ×
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Now showing 1 - 3 of 3
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    ThesisItemOpen Access
    Assessment of losses due to Amrasca biguttula biguttula (Ishida) and management of Earias vittella (Fabricius) on okra
    (CCSHAU, 2014) Chauhan, Vikas; Sharma, S.S.
    The present studies on the assessment of losses due to Amrasca biguttula biguttula (Ishida) and management of Earias vittella (Fabricius) on okra were carried out during kharif season at Research Farm of the Department of Entomology, CCS Haryana Agricultural University during 2013. The losses due to leafhopper were measured by comparing the average plant height, number of fruits per plant and average fruit weight per plant in sprayed and unsprayed plots. The insecticide sprayed plots recorded significantly higher average plant height (66.5 cm), higher average number of fruits (15.6) and higher average fruit weight per plant (164.5 gm) as compare to unsprayed plots. The losses in plant height, number of fruits, and fruit weight per plant due to leafhopper were 47.6, 50.0 and 57.2 per cent, respectively. The management of E. vittella was carried out according the pre fixed insecticide schedules. The observations were recorded by counting the damaged shoots and fruits, total number of shoots and fruits observed at each picking. The mean lowest leafhopper population (1.10 nymph/leaf) was recorded in treatment schedule S 3 (seed treatment with imidacloprid 600 FS @ 5 g/kg seed + 1 st foliar spray with Prempt 20 EC @ 750 ml/ha + 2 nd foliar spray with imidacloprid 17.8 SL @ 100 ml/ha). Similarly, the lowest mite population (4.34 mites/cm 2 ) was recorded in treatment schedule S 2 (seed treatment with imidacloprid 600 FS @ 5 g/kg seed + 1 st foliar spray with Prempt 20 EC @ 750 ml/ha). The lowest shoot damage (1.11%) was recorded in treatment schedule S 8 (S3 + 3 rd foliar spray with thiamethoxam 25 WG @ 100 g/ha + 4 th spray with spinosad 45 SC @ 190 g/ha + 5 th spray with carbaryl 50 WP @ 1.125 kg/ha). The lowest fruit damage on number basis (1.95%) was recorded in treatment schedule S 4 (S2 + 2 nd foliar spray with spinosad 45 SC @ 190 g/ha). On weight basis lowest damage (1.84%) was recorded in treatment schedule S4 . Schedule S 5 (S 2 + 2 nd foliar spray with thiamethoxam 25 WG @ 100 g/ha) was most economical with highest cost to benefit ratio (1:10.25). The population dynamics of the major insect pests and mite on okra were carried out by counting the nymphs of leafhoppers, adults of whiteflies, adults and nymphs of mites at weekly interval from three leaves each from upper, middle and bottom canopy of the plant on randomly selected 50 tagged plants. The leafhopper population was remained throughout the cropping season with minimum population of 1.6 nymphs/leaf in 27 th standard meterological week and the maximum population of 13.9 nymphs/leaf in 32 nd Standard meterological week. Whitefly population was observed during early cropping season with maximum population of 3.4 adults/leaf on 28 th standard meterological week. Mites population was found during later stage of crop growth and the maximum population of 18.2 mites per square cm of leaf in 34 th standard meterological week. The fruit damage by Earias spp. was observed between 31 st to 36 th standard meterological weeks. The maximum fruit damage of 13.9 per cent was recorded on 36 th standard meterological week. There is no significant effect of weather parameters on whitefly and the leafhopper population had negative correlation with maximum temperature and positive correlation with morning relative humidity. Red spider mite population and fruit borer damage caused by Earias spp. was significantly and negatively correlated with minimum temperature.
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    ThesisItemOpen Access
    Diversity, abundance and pollination efficiency of insect pollinators of summer squash (Cucurbita pepo L.)
    (CCSHAU, 2014) Damara, Devika Rani; Kaushik, H.D.
    The present study was conducted with 4 summer squash hybrids viz., Parikrama, Chandra, Chamatkar and Gold Queen at Research Farm of the Department of Entomology, CCS Haryana Agricultural University, Hisar during February-March of 2014. A total of 34 insect species visited summer squash flowers viz., 10 hymenopterans, 8 lepidopterans, 4 dipterans, 5 coleopterans, 2 orthopterans, 2 odonata and 3hemipterans. Among these, A. dorsata, A. mellifera, A. cerana and A. florea were found to be the most frequent pollinators. The abundance (bees/m2/5 minutes) of A. mellifera (2.21) was highest followed by A. cerana (1.16), A. dorsata (1.07) and A. florea (0.62). Irrespective of species, the population was maximum (1.45 bees/m2/5 minutes) at 1000-1200 h of the day. Foragers of A. dorsata, A. mellifera, A. florea and A. cerana commenced their pollen collection activity at 0600, 0630, 0700 and 0700 h, with peak periods at 0600-0800, 0800-1000, 1000-1200 and 0800-1000 h respectively and all of them ceased their activity between 1700- 1800 h. Out of the total foragers of the day for A. mellifera, 47.93 per cent were pollen, 19.01per cent were nectar collectors and 33.06 per cent were pollen+nectar collectors. A. mellifera spent maximum time (10.30 seconds/flower), whereas, A. florea spent least time (2.51 seconds/flower) while these values are 7.61 and 5.10 seconds/flower for A. dorsata and A. cerana. Based on pollination index (loose pollen grains sticking on the body x abundance x foraging rate), A. mellifera was the most efficient pollinator of C. pepo with pollination index of 1177360 followed by A. dorsata (773280 ) and A. cerana (223420) and A. florea with pollination index 63480 under agro-ecological conditions of Hisar (Haryana). Effect of different modes of pollination on yield parameters of summer squash showed that maximum fruit set (73.50%) was observed under open-pollination + hand-pollination treatment and no fruits were observed (0% fruit set) under without insect pollination treatment. Average fruit weight and fruit polar diameter, equatorial diameter was observed maximum (135.30 g, 3.74 cm and 3.47 cm, respectively) under Open-pollination + hand-pollination, while these were observed minimum (94.81 cm, 2.14cm and 2.48 cm, respectively) under hand-pollination treatment.
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    ThesisItemOpen Access
    Evaluation of Bt cotton hybrids against American bollworm Helicoverpa armigera (Hubner) and leafhopper Amrasca biguttula biguttula (Ishida)
    (CCSHAU, 2013) Harish Kumar; Ram Singh
    Six cotton hybrids namely BIO 6488 Bt, BIO 6488 BGII, BIO 6488 non Bt, RCH 134 Bt, RCH 134 BGII and RCH 134 non Bt were used against American bollworm, Helicoverpa armigera and leafhopper, Amrasca biguttula biguttula under laboratory and field conditions during the year 2011-12 in CCS Haryana Agricultural University, Hisar. Survival (%) of H. armigera at 80, 120 and140 days after sowing was affected significantly on Bt and BG II hybrids. The biological parameters of H. armigera viz., larval survival, larval weight, larval period, pupal period, pupal weight and adult emergence were studied at 85, 125 and145 days after sowing (DAS) of crop. Significant effect of Bt and BG II hybrids were recorded on all biological parameters. None of the larvae survived at 85 days after sowing on BG II hybrids, whereas larval survival increased at 125 and 145 days after sowing. Larval weight was recorded minimum on both Bt and BG II hybrids at 80 days after sowing and increased larval weight was observed at 125 and 145 days after sowing. Similar trends were observed in pupal weight and adult emergence on Bt and BGII hybrids. Larval period increased on both Bt and BGII hybrids at 85, 125 and145 days after sowing. Similar trends were observed in pupal period on both Bt and BGII hybrids. In case of ovipositional preference at 85 DAS under choice conditions, females of H.armigera showed no significant difference among Bt, BGII and non Bt hybrids under investigation. Leaves were preferred more over squares, flowers and bolls for egg laying by H.armigera females. The incidence of leafhopper, A. biguttula biguttula was variable between different cotton hybrids at 40 to 90 days after sowing and was observed non significant at 100 to 140 days after sowing. The survival of leafhopper did not differ significantly among hybrids and the development duration was lower on RCH 134 Bt and higher on BIO 6488 BG II. The rate of egg laying did not differ significantly among the different hybrids and main vein supported maximum number of eggs individually.