Yadav, S.S.Rohit Kumar2019-03-272019-03-272018http://krishikosh.egranth.ac.in/handle/1/5810099572The studies on rice weevil, Sitophilus oryzae (L.) with reference to biology on wheat variety WH1105, screening of 15 different varieties of wheat and management through seed protectants were carried out at Storage Entomology Laboratory, Department of Entomology, CCS HAU, Hisar during 2017. Studies on biology of S. oryzae revealed that the eggs of this species were spherical with one end pointed and another rounded, translucent and white in colour and laid singly. The average incubation period of eggs was 5.14 days. There were four larval instars and grubs were apodous, stout, short and yellowish-white in colour with brown-coloured head and pupa was soft, exarate and white to yellowish-white in colour. The average larval and pupal period varied from 28.20 to 32.20 days and an average of 29.72 days under laboratory conditions. Adult male and female lived for 32.28 and 38.46 days, respectively. The average total life cycle of S. oryzae was observed as 34.88 days. The average fecundity was recorded as 189.90 eggs per female. The oviposition period was observed as 24.80 days. Average male and female ratio was recorded as 1:1.19 indicating little dominance of female over male population. Studies on varietal screening revealed that none of the wheat variety found free from infestation of S. oryzae. However, varieties WH283, WH711, DBW17, WH1080, and WH157 were found moderately preferred. Varieties WH-2967, WH542, WH1025 and were found less preferred. Varieties WH1105, WH1124, WH1142, and C306 were least preferred and WH147 was found to be most preferred as the number of eggs, number of adults emerged, grain damage and weight loss was maximum followed by DPW62150 and PBW343. Studies on efficacy of seed protectants revealed that all the seed protectants resulted in significant difference in their effectiveness against S. oryzae. However, neem seed kernel powder, neem oil and custard apple seed powder were found very effective in controlling rice weevils followed by mustard oil, groundnut oil, mustard oil + turmeric powder and groundnut oil + turmeric powder whereas saw dust was found least effective as seed protectant followed by turmeric powder. No adverse effect of these seed protectants was observed on the germination of wheat seed at different intervals whereas the germination was observed to be maximum in the treatment of neem seed kernel powder and neem oil.ennullThesis