An investigation was carried out to assess different foraging activities of Apis mellifera L. in the mustard ecosystem by placing six strong A. mellifera colonies along the borders of mustard fields in the Terai agroecological region of West Bengal during 2019 and 2020. During this period, foragers of A. mellifera had a foraging duration of 9.41 +/- 0.33 hours/day. Their activity was higher during mid-day than in the early morning and late evening hours. Temperature and bright sunshine hours strongly correlate with foraging duration and intensity. On the other hand, relative humidity and rainfall were negatively correlated with bee foraging. Foragers were found to spend maximum time on each flower at 11:00 - 13:00 hours, and their abundance was also high during this time interval. At initial hours of observation, i.e., at 07:00 - 09:00, foraging was minimal. The palynological assessment suggested that the foragers carry about 568,640 +/- 15426.52 pollen on their bodies during peak foraging time. Apart from the pollen of Brassica sp., some other pollen types belonging to Spilanthes sp., and species of Polygonaceae and Solanaceae were also recovered from pollen load. However, these non-Brassica pollen frequency was very low in the pollen spectrum. This study provides information to assist local beekeepers in effectively managing their colonies by correlating foraging activity with weather parameters, and it will also advise mustard growers on establishing a prudent pesticide application schedule that will protect foraging bees from pesticide exposure.

An experiment was conducted in the apiary of Uttar Banga Krishi Viswavidyalaya, Pundibari during 2019. For study, six strong Apis mellifera L. colonies of similar strength were used. A positive and significant correlation of temperature (maximum and minimum) and relative humidity (minimum) with the foraging duration was found. During the cooler months both foraging duration and foraging intensity was minimum and increased later on. Foraging activity was highly affected by rainfall. The mean foraging duration of foragers throughout the year was 11.85± 1.79 hrs/ day. The 25 th standard week was recorded with maximum foraging duration, viz. 14.22 hrs. Foraging intensity was low during initial hours but increased in later hours. Foraging intensity was very less in initial weeks and very high in 10 th to 25 th standard weeks at all the three intervals.

The present study was conducted during September, 2018 to August, 2020 on the seasonal incidence of Vespa tropica Linn. on Apis mellifera Linn. under terai agro-ecological region of West Bengal, India. Ten numbers of A. mellifera colonies of similar strength was placed in the apiary unit of Uttar Banga Krishi Viswavidyalaya, West Bengal, India in which no pest management strategies were carried out. Incidence of V. tropica was recorded higher during July to October peaking in the month of July (251.50±22.17 visits day-1) with annual average success rate of 57.23%±1.16%. From December to March little or no incidence was recorded. Minimum abundance of hornets was recorded at 07:00–09:00 hours. After that incidence started increasing with maximum incidence recorded at 13:00–15:00 hours i.e., 43.52±11.97 visits to the bee colonies day-1 during this time gap. Both maximum and minimum temperature and relative humidity showed significantly positive correlation with the incidence of V. tropica. However, rainfall was found to be detrimental for their incidence as it showed negative and non-significant correlation with their incidence. As V. tropica has been considered as a major enemy of honey bees, so the results obtained from the study can be used for designing integrated pest management strategies against this pest that will allow the beekeepers to focus on that particular time period when this pest is more abundant.

The assessment of botanical origin of honey in northern districts of West Bengal, viz. Coochbehar, Jalpaiguri and Alipurduar districts through melissopalynological analysis is the focus of this study. Ten different honey samples were analysed, from which 78 different pollen taxa representing 34 different plant families have been detected. Asteraceae, Brassicaceae and Fabaceae were the most frequently encountered families. Asteraceae had highest number of representative pollen types (14 types) followed by Fabaceae (11 types). Seven honey samples were recorded as unifloral honey and three were multifloral honey. Litchi chinensis was found as a predominant pollen in two samples, whereas Brassica sp., Canna indica, Leucas aspera, Mimosa pudica and Rosa sp. were the other predominant pollen taxa. In multifloral honey samples Brassica sp. was found to have a higher frequency. Honey samples collected from regions with close proximity during the same season showed a higher similarity index. All the honey samples were poor in honey dew elements (HDEs) having HDE/P ratio (P = total number of pollen grains) of 0.000 to 0.056. The absolute pollen count (APC) varied from 7500 to 696 000 pollen/10 g honey. High variation in pollen spectra with less preference to a particular bee forage in summer honey samples may indicate the onset of dearth period.

At the Uttar Banga Krishi Viswavidyalaya's teaching farm, field tests were conducted on brinjal during the rabi seasons of 2018–2019 and 2019–2020 to assess the field efficacy of seven biorationals and insecticides against Leucinodes orbonalis Guenee, which infests brinjal (Solanum melongena L.). Results showed that Chlorantraniliprole 18.5 SC, Flubendiamide 39.35 SC, and Novaluron 5.25% + Emamectin Benzoate 0.9% SC were the most successful treatments in terms of lowest shoot infestation (2.24-6.05%) and fruit infestation (number basis: 11.01-13.29% and weight basis: 11.94-15.75%). Bacillus thuringiensis var. kurstaki and Chlorantraniliprole 18.5 SC both produced the highest commercial fruit yields, ranging from 13.54 to 14.54 t/ha and 14.11 to 14.51 t/ha, respectively. Azadirachtin 50,000 ppm was found to be the least effective compound against brinjal shoot and fruit borer.

Boro paddy is an important crop in Northern districts of West Bengal, but the crop have to pass through various biotic and abiotic stresses among which insect pest is one of the most important limiting factors. For protecting the crops farmers usually rely upon chemical pesticides that gradually hamper non-target organisms, increase cost of production etc. Among the non-pesticidal alternate technologies, indigenous technology may play pivotal role in bringing sustainability in agriculture. A number of indigenous knowledge based pest management module for boro paddy have been formulated and tested in the agro-ecosystem under consideration during boro season of 2015 and 2016. Inspiring results obtained in field trial from two years of study. Insect pest population observed lowest in chemical based pest management module but natural enemy complex found drastically low. Hence, considering the ill effects of pesticidal application in agro- ecosystem and increasing cost of production, the indigenous technical knowledge based pest management technology may be accommodated as one of the most viable as well as effective tools of IPM in boro paddy.

Efficacy of different wooden blocks as dispenser block of methyl eugenol (Male Annihilation Technique) for attraction of Bactrocera species has been studies. Self-made transparent rectangular PET plastic jars around 1 litter capacity and having four circular holes of 1 cm in diameter on four sides of the jar just below the shoulder of the bottle (i.e. 1/ 3rd from top) openings for the entry of flies. The pooled data of mean weekly catch was recorded highest in plywood dispenser block (13.40 flies/trap/week) followed by mango (13.37 flies/trap/week) and neem (12.67 flies/trap/week) and lowest in babul dispenser block (10.97 flies/trap/week) followed by sissoo (11.28 flies/trap/week) in 7th DAI. The mean persistence period was highest in plywood dispenser block, while lowest in sissoo dispenser block When overall mean values of trap-catch were considered from DAI, highest efficacy was noted by plywood (7.61 flies/trap/week) followed by mango (7.48 flies/trap/week) and neem dispenser block (7.29 flies/trap/week) whereas lowest catch was observed in sissoo (5.67 flies/trap/week) followed by babul dispenser bock (6.06 flies/trap/week). The results also suggested that more number of flies’ species were annihilated in second year of experimentation than first year.

An experiment was conducted to evaluate the efficacy of different food bait prepared from ripened fruit pulps for attraction of Bactrocera species at Pundibari, cochlear, West Bengal during the year 2017 and 2018 at farmer field. Self-made transparent rectangular PET plastic jars around 1 liter capacity and having four circular holes of 1 cm in diameter on four sides of the jar just below the shoulder of the bottle (i.e. 1/ 3rd from top) openings for the entry of flies. The mean values of fly capture of two years pooled data (2017 and 2018) has revealed that statistically highest efficacy of mean number (7.88 flies/trap/day) of flies was captured in T2 (Grape pulp+ 0.5 ml Spinosad 45% SC) and lowest mean number of flies was captured in T5 (Papaya pulp + 0.5 ml Spinosad 45% SC) trap (2.75 flies/trap/day) at 1st DAI. When overall mean values of trap-catch were considered, highest efficacy was noted by using T2 (Grape pulp+ 0.5 ml Spinosad 45% SC) (3.00 flies/trap/day) as bait material followed by T1 (Banana pulp+ 0.5 ml Spinosad 45% SC) (2.47 flies/trap/day), however, two bait material had statistically superior among all the treatments. On the contrary, T5 (Papaya pulp + 0.5 ml Spinosad 45% SC) trap (0.91 flies/trap/day) followed by T6 (Pineapple pulp + 0.5 ml Spinosad 45% SC) trap (1.38 flies/trap/day) recorded the lowest number of flies trapped. These results showed that the efficacy of all the bait materials gradually decreased over time, i.e. at days after preparation and placement of baits. This gradual decrease in the efficacy of the baits may be due to evaporation, drying and other environmental factors. Among the species diversity, only three species were identified B. cucurbitae, B. dorsalis and B. correcta. The dominant species was noted B. cucurbitae range from (48.28%-52.08%) followed by B. dorsalis (40.91%- 44.62%) and B. correcta (4.62%- 11.46%).

Fruit flies (Diptera: Tephtritidae) are one of the most important insect pests to fruits worldwide. In West Bengal, fruit flies have inflicted considerable yield losses especially in mangos (Mangifera indica L.). However, there has been no recent assessment of the associated economic damage impact despite the outcries from the farming communities. The objective of this study was to determination of intensity of infestation by fruit flies in important fruits of mango, to guide the development and improvement of fruit fly control measures in the mango orchard especially northern part of West Bengal. A survey was conducted in the major mango producing areas of the northern part of West Bengal. The fruits were collected from different location of Cooch Behar, Alipurduar, Jalpaiguri and plains of Darjeeling district. From each locations altogether one hundred (100) fruits were collected randomly at three times i.e. early, mid and late stage of the crop during 2014 and 2015. During 2014, results showed that highest fruit infestation on mango (16.33%) by fruit flies was recorded from Chilkir hat (26053′N, 89019′E) and lowest (7.33%) infestation was noted from Matigara (26072′N, 88038′E). However, in the next year i.e. during 2015, the fruit infestation was recorded higher (15.00%) from Naksalbari (26070′N, 88042′E) and lower (7.33%) was recordedfrom Pundibari (26041′N, 89038′E). Pooled mean of both the years of study revealed highest average infested fruit (13.67%) at Chilkir hat localities while lowest (7.83%) at Pundibari on number basis. It was common to experience 100% fruit losses across the agro-ecological zones in the absence of control measures. The situation was increasingly severest with exotic commercial varieties.

Development of an appropriate forewarning system considerably helps to identify the point of time when growth rate of growth of the gundhi bug is at its peak to ensure most effective use of protection measures against gundhi bug infestation. Along with this, it also helps to reduce unnecessary application of insecticides as well as environmental pollution. Hence, in the current study, an attempt has been made to identify the optimum time point of insecticidal spraying. Based on different model selection criteria, cubic model is observed to be the best fit. Optimum time of spraying insecticides against gundhi bug is found to be at 2 DAT.

Recognising the pattern of pest infestation helps greatly to understand the changes in the population dynamics due to several biological, environmental and climatological factors. As data are count in nature, suitable choice of distribution as well as linear or non-linear growth models are obvious to capture the variability present the population. If data are not properly fitted, integrity of scientific inference will be at stake. Hence, in the present study, an attempt has been made to fit appropriate discrete distributions along with the usual linear and non-linear modular approach. Among all the fitted discrete distributions, binomial distribution fits the best, having the minimum Kolmogorov-Smirnov test statistic value and based on different model selection criteria, exponential model is found to be the best fit.

Pumpkin (Cucurbita moschata var Duch. Ex Poir.) is one of the most important cucurbitaceous vegetable crops grown worldwide. Young leaves, flowers, immature and mature fruits of pumpkin are used as vegetable. This cucurbitaceous vegetable suffers severe insect-pest attack due to favourable conditions available for their multiplication and development. The fruit fly, Bactrocera cucurbitae (Coq.) (Diptera: Tephritidae) attacks fruits of the crop and is one of the most important biotic limiting factors. The extent of losses caused by the pest varies from 30-100% depending on cucurbit species and season (Waterhouse, 1993; Dhillon et al., 2005a). Effective management of this dreaded pest is difficult due to its concealed feeding habit and typical life history. Efforts in fruit fly management were focused mainly on mature adult including bagging of fruits, field sanitation, bait traps, cuelure and sterile insect technique (SIT) (Hendrichs et al., 2002), spray of protein baits with toxicants, growing fruit flyresistant genotypes, augmentative releases of biological control agents, and soft International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 10 (2017) pp. 2023-2031 Journal homepage: http://www.ijcmas.com

Twenty pumpkin cultivars collected from different sources from all over India have been evaluated against the infestation of melon fly Bactrocera cucurbitae (Coq.) under terai agro-ecological conditions ofWest Bengal. The cultivars responded variously against melon fly infestation. Intensity of infestation significantly varied from 50 %to 100 % among the test cultivars. Maximum infestation was recorded on cultivar Pumpkin collection, Eluru, followed by Gagan Sardara Para-1, Tripura and Barahmasi, Varanasi, Uttar Pradesh. Minimum percent fruit infestation was observed in cultivars Baidyabati, Debgiri seed, Kolkata, followed by Pumpkin collection, Gagan Sardar Para-2, Tripura, followed by Pumpkin collection, Pasighat-1, Arunachal Pradesh. The variation in melon fly infestation among the cultivars might be due to bio-physical/ biochemical parameters of the fruit.

The predator, Menochilus sexmaculatus (Fb.) in terai region of West Bengal was found active throughout the year and highest population was recorded (9.0/plant) on 13th standard week. Population of Menochilus sexmaculatus (Fb.) showed negative correlation with temperature, relative humidity and rainfall. Field evaluation revealed that the insecticides from biological origin were relatively less harmful to the predator than synthetic insecticides. The pathogen Bacillus thuringiensis ver. kurstaki (Berliner) was less harmful and caused lower killing of the predator (36.58% killing), whereas the synthetic insecticide, DDVP caused higher killing (60.32% killing).

Highest population of flea beetle was recorded (7.16 flea beetles/plant) in 20th standard week. Population of flea beetle showed significant positive correlation with average temperature and non significant negative correlation with average relative humidity and weekly rainfall. Field evaluation of pesticides revealed that DDVP was found relatively more effective against flea beetle on brinjal (33.43% control), followed by avermectin (30.34% control) and neem (30–28% control).