Shankar, UmaHussain, Shailla2021-03-232021-03-232021-03Preferred for your work. Shailla Hussain. 2021. Seasonal Abundance and Management of Major Insect Pests of Linseed (Linum Usitattisimum L.). M.Sc. thesis, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, India.36660https://krishikosh.egranth.ac.in/handle/1/5810162797The thesis embodies the results of experimentation made on Seasonal Abundance and Management of Major Insect Pests of Linseed (Linum usitattisimum L.) carried out during cropping seasons of 2019-20 at Chatha Farm, SKUAST- Jammu. Studies revealed that linseed bud fly, Dasineura lini and pod borer, Helicoverpa armigera were found as the major pests, causing significant damage in different crop growth stages of linseed. The data on damage percentage of bud fly was observed in 6th SW with an initial damage of 1.71(%) and 28.28 (%) in 19th SW and thus constituting the peak. A highly significant positive correlation existed between weekly mean maximum and minimum temperature (0.928** and 0.959**) and per cent damage by bud fly, highly significant negative correlation with relative humidity morning (–0.947**) and significant correlation with evening relative humidity (– 0.649*). The correlation study of abiotic factors on delta trap catches showed that highly significant positive correlation existed between weekly mean maximum and minimum temperature (0.931** and 0.940**) with bud fly catches and highly significant and negative correlation with relative humidity morning and evening (– 0.973** and –0.698**), respectively. The overall impact of weather factors on population buildup of bud fly on linseed was 95.40 and 97.20 per cent, respectively. The incidence of H. armigera was observed during the 6th SW at the bud initiation stage with an initial population of 0.2 larvae/ m row length. Some aberration in moths catches in traps was noticed during 9th SW and 11th SW with mean of 12.33 and 16.67 adult moths. The correlation studies revealed that the highly significant positive correlation existed between weekly mean maximum temperature (0.688**) and pod borer larval density, highly significant negative correlation with relative humidity morning (– 0.696**) and a significant correlation with evening relative humidity (– 0.539*). The overall impact of weather factors on larval population and pheromone trap catches of adults pod borer on linseed was 61.80 and 93.50 per cent, respectively. During the experimentation, beneficial fauna (especially predators and parasitoids insects) activities were observed Coccinellid beetles (Coccinella septempunctata and C. sexmaculata); Rove beetle; Damsel fly; Dragon fly, Tachinid fly, and lynx spider (Oxyopes sp.) a larval endo-parasitoid, Campoletis chlorideae Uchida and naturally infected H. armigera larvae with the virus (HaNPV). Among the different modules tested against linseed bud fly, Module-II was found to be superior in reducing the damage percentage of bud fly and grain yield of linseed was also recorded highest in module II with 9.85 q/ha. Similarly, module III was found to be the best and superior treatment in reducing the larval pest population of H. armigera. In case of yield attributes against H. armigera, all the modules showed significantly different results i.e. Module III (9.64 q/ha) accounted maximum linseed yield than other modules II (8.17 q/ha), I (6.53 q/ha), IV (4.97 q/ha) and V (4.32 q/ha), respectively after harvest.EnglishThesis