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ThesisItem Open Access Influence of floral resources on brood development and honey quality in Apis mellifera (L.)(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-08) Nivedita Krishna; Srivastava, PoonamThe study on the influence of floral resources viz. mustard, litchi, coriander and berseem on brood development and provision content in Apis mellifera (L.) colonies was carried out at G.B.P.U.A.T Pantnagar during the year, 2017-18. The results revealed that the average maximum bee strength was found on Mustard with 5.9±2.08 frames/colony, followed by Berseem (5.5±3.03 frames/colony), Litchi (5.5±3.0 frames/colony) and Coriander (5.5±1.58 frames/colony). However, the brood area was maximum in Litchi (1431.4±202.84 cm2) followed by Mustard (994.1±373.44 cm2), Berseem (675.4±92.67 cm2) and Coriander (409.65±261.33 cm2). Similarly, the maximum pollen area was recorded in Litchi (499.03±107.95 cm2) followed by Mustard (312.11±120cm2), Coriander (297.93±206.78 cm2) but lowest in Berseem (149±8.83 cm2). Maximum nectar area was also found in Litchi (1003.95±362.49 cm2), then Mustard (925.56±385.92 cm2), Berseem (312.11±120 cm2) but minimum in Coriander (94.54±16.76 cm2). However, the honey area was maximum in Litchi (702±62.96 cm2), followed by Mustard (543.06±121.75 cm2), Berseem (351.46±141.90 cm2) and lowest in Coriander (34.29±57 cm2). This study proved that Litchi crop is more suitable bee flora for growth and development of honeybees with maximum brood development and provision content followed by Mustard, Coriander and Berseem. The impact of the various abiotic factors like temperature, relative humidity, sun shine hours on brood development and provision content in A. mellifera was worked out on different flowering period. The maximum and minimum temperature had significant positive relationship with bee strength, pollen area, and brood area which indicates that with increase in temperature there would be increase in bee strength, pollen, and brood area while significant and negative correlation with nectar and honey area decreases. The relative humidity was negative and significantly correlated with there will be decreases in pollen, nectar and honey area whereas, positive impact with bee strength and brood area. Although, the sunshine hours had negative impact on, brood and honey area while positive impact on bee strength, pollen and nectar area. The study on the physico-chemical properties of honey from major bee flora (Mustard, Litchi Coriander and Berseem) revealed that the Mustard honey has significantly higher moisture content (19.56%) and Litchi honey has highest EC (0.58 mS/cm), Total reducing sugar (68.59%), and HMF content (16.91mg/kg). However, Coriander honey showed highest pH (4.39), TSS (82.55°Brix) and Berseem honey has the highest total acidity (47.40meq/kg) and Diastase activity (25.86DN). The colour of different floral honey varies from extra white to amber i.e. Pfund value ranges from 9-114mm. The mean content of Minerals was highest in Mustard honey with Ca:8.54, Fe:2.67ppm, while in Litchi honey Mn:2.68, Mg:263, Ni:0.81ppm , whereas in Coriander honey Zn:1.10 and Cu:0.30ppm, likewise, highest content of Cr:0.50ppm was observed in Berseem honey.ThesisItem Open Access Studies on seasonal incidence and biology of Maruca vitrata (Fabricius) on different pigeon pea genotypes(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-08) Bag, Lokesh; Agnihotri, MeenaThe present investigation was carried out at Norman E. Borlaug Crop Research Centre (NEBCRC) and Pulse Lab, Department of Entomology, College of Agriculture, GBPUA&T, Pantnagar, Uttarakhand during Kharif 2017. Incidence of Maruca vitrata was studied from 39th SW to 51st SW on 6 different genotypes and one local variety (UPAS 120) of pigeon pea. Its presence was first marked during 39th SW at flowering stage and persisted till 51st SW. The mean number of larva was recorded maximum from 42nd SW to 45th SW during flowering stage of the crop. Maximum mean number of larvae (22.01/25 shoots) (flowering stage) of M. vitrata was recorded during 44th SW, whereas minimum incidence of 0.9/25 shoots (maturity stage) was observed during 51st SW. Highest incidence of Maruca vitrata during the whole season was observed on AL 201 (10.81/25 shoots) and lowest incidence was observed on PUSA-2012-1 (4.33/25 shoots) . Mean number of larvae during the season on PAU 881, AL1735, PA 406, PA409 were 8.89, 7.91, 6.92, 5.72 larvae/25 shoots respectively as compared to 6.19 larva/25 shoots on UPAS 120. During the course of investigation on natural enemies on Maruca vitrata. Four parasitoid viz. Therophilus sp. (Braconidae), Apanteles sp. (Braconidae), Elasmus sp.(Eulophidae), phenerotoma sp.(Braconidae) were found. The highest percent parasitization was observed in larvae of Maruca vitrata by Therophilus sp. (66.16 per cent), followed by Apanteles sp. which is 18.93 percent, Elasmus sp. (10 per cent) and Phenerotoma sp. (2.9 percent). Biology of Maruca vitrata was also studied in the laboratory condition on 6 different genotype with a local variety (UPAS 120). Observation on different parameters of biology like egg period, duration of different larval instars, duration of total larval period, duration of pupal period, male longevity and female longevity were recorded on different genotypes. Egg period was found to be longest in PA 406 (3.62±0.10 days) and shortest in AL 201(2.93±0.04 days), total larval period was longest in PUSA-2012-1(12.80±0.20 days) and shortest in AL 201(10.26±0.37), pupal period was longest in PA 406 (9.21±0.31days) and shortest in UPAS 120 (8.41±0.09 days). Data on consumption and utilisation of flowers by third instars and pod by fifth instar was studied wherein Efficiency of conversion of digested food in to body matter (ECD) was lowest in PUSA-2012-1, while Approximate digestibility (AD) was the lowest on AL 201 and Efficiency in coverting ingested food into body matter (ECI) values were lowest on PA406 for the third instar. While, Efficiency of conversion of digested food in to body matter (ECD) was lowest in PUSA-2012-1, while Approximate digestibility (AD) was the lowest on AL 1735 and Efficiency in coverting ingested food into body matter (ECI) values were lowest on PUSA-2012-1in fifth instar. Biochemical analysis of all the genotype were done for phenol and flavonoid content and correlated with the incidence as well as biology of Maruca vitrata. The phenol content was found to be highest in PUSA-2012-1(1.732mg/g) and lowest in AL 201(0.520mg/g). Highest flavonoid content was recorded in PUSA-2012-1(5.863mg/g) and lowest in AL 201 (2.198mg/g). Phenol content and flavonoids content in the seed was found to have significant negative correlation (-0.794*) and (-0.770*) respectively with % pod damage by Maruca vitrata. Duration of all the larval instars of the Maruca vitrata showed significant positive correlation with both phenol content and flavonoid content in the seed.ThesisItem Open Access Studies on phylogenetic divergence in genus Helicoverpa and resistance mechanism in chickpea genotypes against its major pests(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-08) Reddy, Morthala Shankara Sai; Agnihotri, MeenaThe present investigations were carried out on “Studies on phylogenetic divergence in genus Helicoverpa and resistance mechanism in chickpea genotypes against its major pests” during 2016-2018. The studies revealed that in genus Helicoverpa, Helicoverpa armigera species is present in all the thirteen districts of Uttarakhand at over altitude range of 227.7 m (Pantnagar) to 2049.7 m (Barsar). In Pantnagar H. armigera infestation was found throughout the year on forty plant species belonging to fifteen families, which includes thirteen field crops, eight vegetable crops, thirteen ornamental plants and six herbaceous weeds. Preferred host plants mostly from the Fabaceae family. The larval and adult populations of H. armigera showed negative correlation with the variables minimum temperature, morning relative humidity, evening relative humidity and rainfall whereas positive correlation with maximum temperature, and sun-shine hrs. Five peaks of adult male moth catches were recorded during 2016-17. Major peak of moth population catches was high during the 15th S.W. The studies of Inter-host phylogenetic analysis at Pantnagar, revealed a total of fifteen single nucleotide polymorphisms (SNPs), one semi- conserved amino acid among the eleven isolates of H.armigera population. Evolutionary adoptive change in wheat population of H. armigera was found to be newly establishing at Pantnagar where host fidelity factors playing an important role. Whereas, Inter-location phylogenetic analysis revealed that thirty three single nucleotide polymorphisms (SNPs), twelve semi conserved and seven un-conserved amino acid residues among the eleven different location isolates of H. armigera population. The high similarity may be attributed to the altitudinal similarity among the collected population i.e., Jakhdhar (1713.6m) and Ranichauri (1861 m). The H. armigera population of Dehradun, Ranipokhari and Chinayalisaur have formed same cluster depicting the trade route of agriculture products. In studies of resistance mechanism, out of thirty nine chickpea genotypes eleven genotypes showed resistance against H. armigera among them two genotypes NBeG1004 and GL25016 were having comparatively sparse trichome density and lengthier trichomes which were least infested by eggs of H. armigera. The biochemical experiments revealed the highest phenols, flavonoids, tannins and trypsin inhibitor observed in GL25016, ICCV97105, GL25016 and NBeG1004. The GCMS analysis showed that ICCV92944 was containing compounds such as Octanoic acid, 2-dimethylaminoethyl ester, Phytol, Phthalic acid and Tetradecanoic acid which might be showing some adverse effects on H. armigera growth and development and might be reason for resistance against H. armigera. Accessions having combination of suitable sparse and lengthier trichomes on leaves and pods and higher biochemical parameters viz., phenol, flavonoids, tannins and trypsin inhibitor content in their immature seeds offered resistance against pod borer attack in chickpea. The resistance towards the Callosobruchus chinensis was offered by HC1 and ICCV92944. The biochemical experiments revealed highest amounts of phenols, flavonoids, tannins and trypsin inhibitor observed in GL25016, HC1, ICC07104 and in NBeG1004. Bioactivity compound 9-Octadecenoic acid (Z) - was found in only HC 1 which may be reason for resistance against C. chinensis. The genotypes viz., ICCV 92944 and HC 1 which are least preferred by H. armigera and C. chinensis, respectively could be exploited as a source of resistance for the varietal development of chickpea germplasm against H. armigera.ThesisItem Open Access Bioefficacy of some new molecules and neemazol against major pests of chilli crop (Capsicum annuum L.)(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-07) Yadav, Atul; Karnatak, A.K.During present investigation different insecticides formulations were tested against sucking pests and fruit borer, infesting chilli crop. Present study was a documentation of evaluation of newer insecticides formulations against major insect pests in chilli crop indicated that incidence of aphid, thrips, white fly, fruit borer and mite commenced on crop around 10-15 days after transplanting. Among the different insecticides tested against major insect pests of chilli, the treatments Profenophos 50% EC + Emamectin benzoate 5% SG @ 1250 g/ha, Profenophos 50% EC + Emamectin benzoate 5% SG @ 1500 g/ha, Profenophos 50% EC + Emamectin benzoate 5% SG @ 1000 g/ha, Imidacloprid 17.8% SL @ 100 ml/ha, Fipronil 5% SC @ 1000 ml/ha, Emamectin benzoate 5% SG @ 220 g/ha were found most effective and the maximum fruit yield of chilli was also obtained in these treatments, while the treatments Profenophos 50% EC + Emamectin benzoate 5% SG @ 750 g/ha and Neemazol 0.15% EC @ 3000 ml/ha were least effective. The incidence of thrips on winter chilli crop has been observed from 47th standard meteorological week (SMW), 2017 to 15th standard meteorological week, 2018 with peak population in 7th standard meteorological week. Whereas, the incidence of aphid, whitefly and fruit borer has been found from 47th standard meteorological week (SMW) to 15th standard meteorological week, 47th standard meteorological week (SMW), 2017 to 15th standard meteorological week, 49th standard meteorological week (SMW), 2017 to 15th standard meteorological week with peak in 7th SMW, 6th SMW and 6th SMW respectively. In 2017-2018 maximum yield of 12.83 q/ ha was obtained in chilli crop treated with Profenofos 50% EC + Emamectin benzoate 5% SG @ 1250 g/ ha. Neemazol 0.15% EC @ 3000 ml/ha found to be safest insecticide against the natural enemies of chill pests.ThesisItem Open Access Bio-intensive pest management strategies for mango shoot gall psylla, Apsylla cistellata Buckton(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-07) Raina, Jyoti; Srivastava, PoonamStudies carried out on different biological attributes of mango shoot gall psylla, Apsylla cistellata showed that pre-oviposition, oviposition and post-oviposition period of shoot gall psylla female varied from 10-22, 1-5 and 0-3 hours, respectively. A single female laid 45-182 eggs and incubation period of eggs varied from 138-177 days. It was also found that females outnumbered males and sex ratio was computed to be 1: 1.64 -1.79 (male: female). Data also indicated that number of galls/twig became proportionately higher as the number of eggs bearing leaves increased on a twig (40 cm). It was observed that, if all the leaves of twig carry 200 eggs, the number of galls formed were maximum (40 and 41 galls/ twig), by converting all buds to galls. Correlation analysis indicated that number of eggs were positively significantly correlated with gall formation (r=0.923, 0.916) and adult emergence (r=0.956, 0.945). Whereas, significantly negatively correlated with panicle initiation (r= -0.885,-0.881). Seasonal incidence of mango shoot gall psylla indicated that nymphal emergence initiated from 33 SW and continued to 39 SW, whereas gall formation started in the 38 SW and appeared constantly in every week till 15 SW. It was also recorded that nymphs 1st appeared inside galls in 41 SW and further observed in every week till 6 SW. Later, nymphs transformed into adults and adult population started appearing inside galls from 8 SW which continued upto 17 SW. However, oviposition of psylla was recorded only during the 12 to 18 SW in the month of March and April. Correlation coefficient stated that nymphal emergence had positive significant association with maximum temperature (r= 0.434), minimum temperature (r= 0.830) and rainfall (r= 0.652). However, gall formation and nymphal population inside galls was found negatively correlated with maximum temperature (r= -0.791, -0.579) and minimum temperature (r= -0.728, -0.575). Whereas, egg laying of shoot gall psylla was significantly positively correlated to maximum temperature (r= 0.419) and negatively correlated to morning (r= -0.658) and evening R.H (r= -0.348), respectively. Studies on evaluation of yellow and blue coloured sticky traps for visual preference during adult emergence period in the month of March-April indicated that adults were attracted more towards yellow sticky traps (6.96-7.82 adults/trap/week) as compared to blue sticky traps (1.91-2.40 adults/trap/week). Traps installed at upper height were found significantly better with maximum number of adults as compared to traps installed at lower height. Different plant extracts were also evaluated against oviposition of shoot gall psylla, which indicated neem leaves extract and hemp leaves extract were found highly effective with minimum number of eggs and highest oviposition deterrence (30.26-74.61%) in all the concentrations. Data on the efficacy of different insecticides showed that thiomethoxam @ 1g/l & 3 g/l and imidacloprid @ 0.5 ml/l and 1 ml/l proved most effective with highest nymphal mortality (54.33-73.04%), minimum gall formation (0.07-2.94 galls/twig), maximum panicle initiation (1.75-4.50 panicles/twig) and minimum nymphs inside galls (0.00-1.80 nymphs/gall/twig). Impact of different plant growth regulators on shoot galls showed that NAA and 2,4-D were found superior over other plant growth regulators with their ability to open the galls, at 100, 250 and 500 ppm. Galls were opened abnormally in both the treatments, having an elongated axis with completely lose and open scales. Nymphs further were not able to survive in those opened galls. However, 2,4-D at higher doses (500 ppm) caused phytotoxicity symptoms on leaves and galls. Although, such kind of phytotoxicity was not found due to the spray of NAA even at higher doses (500 ppm).ThesisItem Open Access Management of Helicoverpa armigera (Hubner) using biorationals and low cost traps in chickpea(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-08) Ajaykumara, K.M.; Tiwari, RuchiraTo evaluate the efficacy of biorationals, such as animal urine collected from cow, buffalo, ox, goat, horse and used @20%, leaf extracts of congress grass, lantana, ekka, sugar apple, glory bower, nilgiri, Mexican prickly poppy plant and fruit extracts of chinaberry, karanj, jatropha, datura, golden shower, babool and algaroba @5% and to develop the attractant based low cost traps against H. armigera on chickpea, the studies were conducted under field and laboratory conditions during rabi crop seasons, 2016-17 and 2017-18 at Pantnagar, Uttarakhand. The field studies clearly showed that among the different plant and animal origin biorationals, Desi cow urine, horse urine, goat urine, fruit extracts of chinaberry, jatropha, karanj and datura were found effective against H armigera with mean larval population, pod damage and grain yield ranged from 2.83 to 4.06 larvae/10 plants, 13.00 to 18.80 per cent and 10.85 q/ha to 12.92 q/ha, respectively which was significantly higher than untreated control (11.78 larvae/10 plants, pod damage-38.70 per cent and grain yield-5.51q/ha). All the biorational treatments were found safe for the natural enemy, Campoletus chloridae with the mean cocoon population ranged from 1.51 to2.51 per ten plants in comparison to insecticide, indoxcarb (0.76/10 plants). The attractant based low cost traps with different plastic bottle models were constructed based on different host plant extracts, sweet baits, radium colored tape to catch adult moths of H. armigera on chickpea. The trap model design with top 1/4th portion inverted in down 3/4th portion of 1 litre plastic water bottle was found the best with bait of 300 ml of boiled jaggery solution @50% per trap for trapping significantly higher number of moths H. armigera with lessen effects on non target insect groups in chickpea crop ecosystem. The cost of this invented insect trap was calculated six times less i.e. only Rs 10.00 per trap than helilure based pheromone trap costs Rs 60.00 per trap. The laboratory studies on growth regulatory effect of different biorationals again showed the best efficacy of Desi cow urine, horse urine, goat urine, fruit extracts of chinaberry, jatropha against H. armigera as they caused cent per cent mortality of neonate larvae whereas fruit extracts of karanj, sugar apple, glory bower and leaf extracts of ekka plant and congress grass gave very less growth index values (0.087, 0.268, 0.362, 0.375and 0.676) in comparison to untreated control (2.631). The studies conducted on antifeedant activity of biorational treatments against 4th larval instar of H. armigera showed that Desi cow urine, horse urine, goat urine, leaf extracts of ekka plant and sugar apple, fruit extracts of chinaberry, karanj and datura were found with strong antifeedant action with preference index between (0.35 to 0.50) The olfactometer based preliminary studies clearly indicated that jaggery solution @50% and stored for 10 days was quite effective to orient or attract the adult moths of H. armigera. Thus, it can be concluded that, the tested plant and animal originated biorationals and attractant based low cost trap models can surely be incorporated in an integrated pest management programme of H. armigera as they are easily available, cost effective and eco-friendly for management of this notorious pest in chickpea crop ecosystem.ThesisItem Open Access Studies on genetic variability of predatory stink bug (Eocanthecona furcellata Wolff) in Kumaon region of Uttarakhand(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-06) Bhatnagar, Vinayak Raj; Maurya, R.P.The present investigations were carried out during 2017-18 at various locations in Kumaon region of Uttarakhand and laboratory studies were done in Bicontrol laboratory, Department of Entomology, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar. Results of the study of distribution and host range of Eocanthecona furcellata in Kumaon region reveal that the preferred host of this predatory bug in the region are Amaranthus leaf eating caterpillar (Hymenia recurvalis), Wheat army (Mythimna separata), Tobacco caterpillar (Spodoptera litura), Spotted pod borer (Maruca vitrata), Poplar defoliator (Clostera fulgurita), Gram pod borer (Helicoverpa armigera) and Rice leaf folder (Cnaphlocrosis medinalis). Study of biology of various strains of the predatory stink bug, E. furcellata on rice meal moth, Corcyra cephalonica, revealed that incubation period varied from 6.33±0.57 days to 7.00±1.00 days. Total nymphal period varied from 24.33±1.32 to 27.00±1.83 days. Adult longevity ranged from 13.00±1.00 to 16.67±1.52 days. Study on predatory efficiency revealed that first nymphal instar fed on plant sap. Feeding on C. cephalonica larvae started from second instar. The rate of predation in the nymphal instar varied from 69.86 to 88.6 per cent; in adults it varied from 69 to 75.71 per cent. The variation in the mean predation rate was from 74.89 to 79.28 per cent. The results of the study of genetic variability of E. furcellata in Kumaon region reveal that the strain of the predatory bug from high hills was found to be particularly distant (07% similarity) from the strains belonging to mid hills, valley region and tarai region. Hence, it was concluded that E. furcellata is widely distributed in Kumaon region and feeds on a wide range of hosts. There was no significant change in the biology and predatory efficiency of the predator with change in geographical and climatic conditions of the habitat, even in genetically diverse strains. This suggests that the predator has adapted itself (genetic diversity) to survive the extreme climatic conditions but has still maintained its biological attributes. So, the use of local strains of the predators in the biological control programs is recommended.ThesisItem Open Access Studies on insect pollinators and their impact on yield parameters in pigeon pea, Cajanus cajan (L.) Millspaugh at Pantnagar(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-06) Banik, Supratik; Khan, M.S.The field experiment was conducted during kharif season of 2017-18 at experimental site of Normon E Borlaug Crop Research Centre (NEBCRC) of G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand to study the diversity, abundance and pollination efficiency of insect pollinators, effect of commonly used insecticides on their abundance and impact of insect pollination on yield parameters in pigeon pea crop. Twenty five different species of flower visitors belonging to 14 families and 6 orders were found visiting flowers in pigeon pea field. Among them 10 bee species from the families Megachilidae, Apidae and Halictidae were identified as potential pollinators from their abundance. The megachilid bees dominated over others (Apidae and Halictidae) in their abundance in five of the six varieties studied. The varieties UPAS-120, PA-3, PA-421 had highest abundance of Megachile disjuncta while the varieties PA-406 and PA-441 had maximum abundance of M. bicolor. In the variety PA-291, the honey bee Apis dorsata was the most frequent flower visitor. The prevailing abiotic factors (Temperature and RH) had positive but non-significant correlation with abundance of most insect pollinators. Most insect pollinators preferred varieties PA-441, PA-421 and UPAS-120 over others for their visitation. There was significant positive correlation of abundance of insect pollinators with nectar volume (r = 0.989) and sugar concentration (r = 0.991). Among the pollinators of pigeon pea, M. disjuncta was the most efficient pollinator followed by Xylocopa latipes and M. bicolor. The six insecticides (Quinalphos 25% EC higher and lower dosage, Lufenuron 5.4% EC, Deltamethrin 2.8% EC, Emamectin benzoate 5% WG and Indoxacarb 15.8% EC) evaluated for their effect on the visitation of insect pollinators were found to have variable repellency effect on different pollinators and also the insect pollinators showed differential response to individual insecticide. The insecticide Indoxacarb 15.8% EC @50 g a.i/ha and Deltamethrin 2.82% EC @12.5 g a.i/ha had relatively lower repellency affect on most insect pollinators. Significantly higher values for yield parameters (pods/plant, pod length, seeds/pod and seed index) in variety UPAS-120 were obtained in insect pollinated plants over self-pollinated.ThesisItem Open Access Studies on dissipation kinetics and risk assessment of imidacloprid residues and bioefficacy of some insecticides against Hemipteran pest in okra(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-06) Joshi, Sneha; Srivastava, R.M.In the present study field investigations were carried out at Vegetable Research Centre, G.B. Pant University of Agriculture and Technology, Pantnagar during spring and rainy season of 2017, respectively. Three species of hemipteran insect pest viz., leafhopper (Amrasca biguttula biguttula Ishida), Whitefly (Bamisia tabaci Genn.), Aphid (Aphis gossypii Glover) were observed to attack the okra crop during both spring and rainy season 2017. Among all the insecticidal treatment, imidacloprid 17.8 SL @ 100ml/ha followed by acetamiprid 20 SP @ 75 gm/ha was found to be highly effective against aphid and leafhopper population and thiamethoxam 25% WG @ 100 gm/ha was found most effective to suppress whitefly population. Yield was recorded maximum in acetamiprid 20 SP@ 75gm/ha treated plots. Yield of okra in rainy season (15.17/ha) was more than spring season (13.04 T/ha). Seasonal incidence of all the pest under study was observed from 13th standard meteorological week to 25th standard meteorological week of 2017. Maximum mean population of leafhopper (16.10 leafhopper/3 leaves) and whitefly (15.31 whiteflies/3 leaves) was recorded during 21st SMW of 2017.And peak population of aphid (31.52 aphids/3 leaves) was observed during 21st SMW of 2017 in spring season. During rainy season of 2017, seasonal incidence of all the pest species under study was studied from 32nd standard meteorological week to 43rd standard meteorological week of 2017. Maximum mean populations of leafhopper (12.12 leafhopper/3 leaves), whitefly (12.85 whiteflies/3 leaves) and aphid (20.98 aphids/3 leaves) were recorded during 40th SMW of 2017. Residue of imidacloprid was dissipated to more than 80 % after 3 days of spraying and it was found to be below detectable limit at 7 and 10 days. Half life period for imidacloprid at tarai region of north western Himalaya was estimated to be 2.094 days at recommended dose. As the RQ (Risk Quotient) value was found to be less than 1 after 3 day (0.85).Hence, 3 days waiting period have been suggested for imidacloprid in okra crop in agroclimatic region of tarai during rainy season.