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Subject: Entomology × End date: 2017 × Start date: 2017 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Effect of different artificial food on the growth and development of honeybee, Apis cerana (Hymenoptera : Apidae)
    (AAU, Jorhat, 2017-07) Borah, HEMI; Deka, M. K.
    Experiment was conducted during 2016 in the Apiary and Apiculture Laboratory, Department of Entomology, AAU, Jorhat to see the “Effect of different artificial food on the growth and development of honeybee, Apis cerana (Hymenoptera: Apidae)”. It was found that the colony strength was found to be maximum (6.50±0.36) and (7.25±0.26) in the treatment 5 (Soybean flour + Sugar solution + Yeast + Vitamins) and lowest was found to be (5.57±0.58) and (6.30±0.82) at treatment 7 that is sugar solution (Control) after 7 and 15 days respectively. The highest egg area (20.22±1.79cm²) and (24.54±1.43cm²) was observed in the treatment 5 and lowest was found to be (16.26±1.97cm2) and (20.32±1.16cm²) at treatment 7 after 7 and 15 days respectively. Likewise, the maximum larval area (17.19±1.68cm²) and (20.35±0.85cm²) was observed in the treatment 5 and minimum was found to be (11.45±0.42cm2) and (13.39±1.51cm²) at treatment 7 after 7 and 15 days respectively. And the highest pupal area (17.62±1.10cm²) and (24.34±0.58cm²) was observed in the treatment 5 and lowest was found to be (11.24±0.57cm²) and (18.22±1.13cm²) at treatment 7 after 7 and 15 days respectively. The maximum pollen area was observed after 7 days (9.32±2.09 cm²) and 15 days (14.49±1.12cm²) in treatment 5 and lowest was found to be (5.48±1.43cm²) after 7 and (8.23±0.99cm²) after 15 days at treatment 7. The highest honey hoarding was observed after 7 days and 15 days of treatment in treatment 5 are (15.10±0.57cm²) and (22.97±1.09cm²) and lowest was found to be (10.96±0.04cm²) and (15.40±0.24cm²) at treatment 7 respectively. The highest length of larvae was observed (0.67±0.02cm) after 5 days of treatment in treatment 5 and lowest was found to be (0.50±0.10cm) at treatment 7. The maximum breadth of larvae was observed (0.35±0.04cm) after 5 days of treatment in treatment 5 and lowest was found to be (0.28±0.10cm) at treatment 7. The highest weight of larvae (0.33±0.02gm) was also observed in treatment 5 after 5 days of treatment and lowest was found to be (0.27±0.02gm) at treatment 7. The maximum length of pupae (1.00±0.06cm) was observed after 12 days of treatment in treatment 5 and minimum was found to be (0.88±0.06cm) at treatment 7. The highest breadth of pupae (0.46±0.06cm) was observed after 12 days of treatment in treatment 5 and lowest was found to be (0.39±0.06cm) at treatment 7. Likewise, the highest weight of pupae (0.36±0.03gm) was observed after 12 days of treatment in treatment 5 and lowest was found to be (0.30±0.02gm) at treatment 7. The enemies occurred in the colonies during the year were wasps, waxmoth, ants, lizard and cockroach. The diseases found in the colonies during observation were Thaisac brood and Nosema. The lowest larval mortality was observed (0.10±1.00%) after 5 days of treatment in treatment 5 and 3 and highest (0.67±0.58%) was found at treatment 7. The minimum pupal mortality (1.26±1.15%) and (0.23±1.00%) was observed in treatment 5 and maximum was found to be (1.67±1.00%) and (0.59±1.15%) at treatment 7 after 7 and 12 days of treatment respectively. However lowest adult mortality was observed (1.33±0.58%) and (0.56±0.58%) after 7 and 15 days of treatment in treatment 5 and highest was found to be (1.67±1.15%) and (0.67±0.58%) at treatment 7 respectively. The various meteorological factors viz. temperature, relative humidity and rainfall influenced the brood area, weight of larvae and pupae. Maximum temperature and maximum relative humidity showed positive correlation with brood area, weight of larvae and pupae. On the other hand, minimum temperature, minimum relative humidity and rainfall showed negative correlation with brood area, weight of larvae and pupae.
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    ThesisItemOpen Access
    INTRAGUILD PREDATION AND INTERACTION BETWEEN Coccinella transversalis Fab. AND Coccinella septempunctata L. ON EGGPLANT
    (AAU, Jorhat, 2017-07) Rohman, Mohsin Musaddik; Devee, Anjumoni
    The experiment on Intraguild predation and interaction between Coccinellatransversalisand Coccinellaseptempunctata were carried out during 2015- 2017 at Experimental Farm, Deptt. ofHorticulture and the laboratory, Deptt. ofEntomology, Assam Agricultural University, Jorhat. Two species of aphid viz., Aphis gossypii and Myzuspersicaeandsix species of coccinelliid predators viz., C.transversalis, C.septempunctata,Cheilomonassexmaculata, Harmoniadimidiata, BrumoidessuturalisandMicraspis discolor were collected and identified from eggplant. TheA.gossypii(36.04%) was comparatively more abundant on eggplant than M.persicae(17.04%) at field andA.gossypiiwas found throughout the cropping season. Among the coccinellid predators, C.transversalisand C.septempunctatawere most dominant with their relaiveabundance 1.12% and 0.99%, respectively. Besides aphids, five other insect pestsviz.,Bemisiatabaci, Leucinodesorbonalis, Amrascabiguttulabiguttula, HenosepilachnavigintioctopunctataandMonoleptasignatawere found to infest eggplant during 2015-2017. The coccinellid predators plays important role in control of aphids population. When observed the intraguild predation between dominant predator C.transversalisand C.septempunctata in presence of extra guild prey A.gossypii, it was found thatthemean consumption of A. gossypii by a singleC. transversalis3rd instar and 4th instar grub were 48.10±1.83 and 77.75±2.43, respectively. While, the mean consumption ofA. gossypii bya singleC. septempunctata, 3rd instar and 4th instar grub were 47.80±1.60 and 69.95±1.63, respectively.When both the predator were released together in different combinations like C.transversalis(4th)×C. septempunctata(4th), C. transversalis(4th)×C. septempunctata(3rd),C.transversalis(3rd)×C. septempunctata(4th) andC. transversalis(3rd)×C.septempunctata(3rd) and their consumption were 91.55±0.81, 84.73±0.83, 83.88±0.72 and 72.006±0.81, respectively. The combined effect of these two predators was assessed by Multiplicative Risk Model and it was found that in all combinations, the observed consumption was significantly lower than the expected consumption, except in case of ofC. transversalis(3rd)×C. transversalis(3rd) instar.This indicated that in lower instars for food competition was less in comparison to higher instars. When different instars of C. septempunctatawere combined together in all cases the expected consumption was always significantly higher than the observed consumption. This indicated that there was some harmful or intraspecific effect among the different instars of C.septempunctata, when consumed prey. When both the predators released together in different combinations, the expected consumption of combination of both the predators was significantly higher than the observed consumption and it indicated the antagonistic effect of both the predators in presence of sufficientA. gossypiipopulation.When observedintra and interspecific interaction between both the predators in presence of sufficient A. gossypii, there was no cannibalism in both the species.But in absence ofA. gossypii,C.septempunctata, showed highest intraspecific cannibalism(53.30%) among 3rd and 4thinstar and lowest (13.33%) was observed in between C. transversalis(4th)×C. transversalis(4th). The interspecific interaction in absence of aphids, C. septempunctata(4thinstar)cannibalised maximum(35%) on C. transversalis (3rd) and lowest(10%) was registered by C. transversalis(3rd) on C. septempunctata(3rd) instar. Adults of both the species cannibalised 100% of conspecific and heterospecific grub in absence of aphid.As the experiment was done on petri dish and both the predators showed antagonistic effect, thus it is recommended not to release these two coccinellid predators together in protected cultivations and the experiment should be repeated in potted plants and open field conditions.
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    ThesisItemOpen Access
    Development of bio-intensive IPM module against insect pests of rice
    (AAU, Jorhat, 2017-07) Borah, Binita; Das, Purnima
    Field experiment were carried out carried out in ICR (Instructional cum Research) Farm during Sali and Ahu season 2016-2017. Incidence of major pest stem borer, leaf folder, caseworm, whorl maggot and gundhi bug and their natural enemies viz., coccinellid, spiders, and dragonfly/damselfly were recorded throughout the crop growth period. However, the stem borer, leaf folder, caseworm, whorl maggot and gundhi bug were more prominent during Sali season, 2016 and stem borer, leaf folder, caseworm, whorl maggot and gundhi bug were prominent during Ahu season, 2017. Among all the pests, the stem borer was most dominant (6.16% DH) and leaf folder was least dominant (3.93%) at early stage of crop during Sali season, 2016 whereas, during Ahu season, 2017 the whorl maggot was most dominant (9.76%).The correlation study revealed that the infestation of different pests and their natural enemies was influenced by the weather parameters in both the years. Correlation studies during Sali, 2016 revealed that infestation of stem borer had significant negative relation with Tmax (r= -742) and significant positive relation with RH (mor) (r =0.795). The infestation of leaf folder had significant negative relation with Tmin (r =-0.804), RD (r =-0.499), RH (mor) (r =-0.760); and the infestation of caseworm had significant negative relation with Tmin (r =-0.848), RD (r=-0.535); whereas it showed significant positive correlation with RH (mor) (r =+0.709). Gundhi bug had significant negative relation with Tmax (r =-0.775), with Tmin (r=-0.930). Correlation studies during the Ahu season, 2017 showed that the infestation of whorl maggots had significant positive relation with Tmax (r =+0.741) and Tmin (r =+0.972) and the infestation of stem borer had significant positive relation with Tmax (r =0.726) and Tmin(r =0.942) and no significant relation was found between gundhi bug and meteorological parameters during Ahu, 2017. Out of the eight treatment tested, the treatment combinaton of Beauveria bassiana WP @ 10gm/lit along with sub-lethal dose of chlorpyriphos 20EC @ 1ml/lit was found to be most effective in reducing the infestation of stem borer, leaf folder,case worm and whorl maggot during during Sali and Ahu 2016-2017.
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    ThesisItemOpen Access
    POPULATION DYNAMICS OF APHIDS AND THEIR ROLE IN INCIDENCE ON VIRAL DISEASES OF POTATO, Solanum tuberosum L.
    (AAU, Jorhat, 2017-07) Debbarma, Dipendu; Bhattacharyya, Badal
    Field and laboratory investigations were carried out to know the population dynamics of potato aphids and their role in disseminating viral diseases at Assam Agricultural University, Jorhat during 2016-17. Experimental results delineates the presence of only one species of aphid (Myzus persicae Sulzer) and found active from 2nd week of December, 2016 to 1st fortnight of February, 2017. The lowest (0.19 / leaf) and highest (2.56 / leaf) population of M. persicae was recorded on 15th December, 2016 and on 26th January, 2017, respectively. Correlation studies between weekly mean population of aphids / leaf and different meteorological parameters registered significant negative correlation with the morning (r=-0.843) and evening (r=-0.673) relative humidity. However, other meteorological parameters viz., maximum and minimum temperature, total rainfall and BSSH were found to be non significant. Altogether eight different species of coccinellids viz., Mecraspis discolor (Fab.), Cheilomenes sexmaculata (Fab.), Coccinella transversalis (Fab.), Coccinella septempunctata L., Brumoides suturalis (Fab.), Propylea sp., Harmonia dimidiata (Fab.) and Coelophora saucia (Mulsant) and one species of spider (Neoscona sp.) were recorded during the course of the study. The maximum population of coccinellids (0.32/plant) coincided with the peak aphid population (2.56/leaf). Correlation studies of M. persicae with their aforementioned natural enemies revealed a highly significant positive relationship. Significant negative correlation with morning relative humidity was registered for both cocinellids (r=-0.734) and spider (r=-0.809) population. However, other meteorological parameters viz., maximum and minimum temperature, total rainfall and BSSH were found to be non significant. The first incidence of viral disease was observed after 42 days of sowing of potato and the maximum disease incidence (28.39%) was recorded on 2nd week of February, 2017. Altogether ten alternate hosts of M. persicae viz., Melastoma melabathricum L., Mikania micrantha Kunth, Chromolaena odorata L., Ageratum houstonianum Mill., Solanum nigrum L., Hibiscus rosa-sinensis L., Lycopersicon esculentum Mill., Capsicum annum L., Solanum melongena L. and Spilanthes calva DC. were recorded from the vicinity of the experimental plots. Out of these, potato leaf roll virus was detected only in Melastoma melabathricum L. besides potato leaves and M. persicae.