Biology and Management Of Lesser Grain Borer Rhyzopertha Dominica fabricius Coleoptera Bostrichidae

Abstract

Delineate the Biology and management of Lesser grain borer, Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae)quotlaboratory experiments were conducted at the Department of Entomology, MSSSoA, Centurion University of Technology and Management, Parlakhemundi, Gajapati, Odisha during 2021-2023. The lesser grain borer (LGB), Rhyzopertha dominica (Fabricius), a major pest in storage could complete its life cycle on paddy variety RNR-1504 and wheat variety KW-51 across a year in Odisha. On paddy the mean number of adults emerged in one generation in the rainy, winter, and summer seasons were 277, 158, and 75 with Female: Male ratio of 1.27:1; 1.08:1 and 0.72:1 respectively while the corresponding figures on wheat were 265, 154, newlineand 111 exhibiting sex ratio of 1.38:1, 1.17:1 and 0.93:1 respectively. Irrespective of season, females LGB lived for a longer period than male on both paddy and wheat. Screening of 20 paddy varieties revealed that the susceptibility index ranged from 1.94 to 9.08. Three varieties viz. CR Dhan 206, Sneha, and CR Dhan 201 scoring less than newline3.0 are categorized as resistant while sixteen varieties were moderately resistant and one variety was found to be susceptible. The growth index of the resistant varieties, Sneha, CR Dhan 206, and CR Dhan 201 were 0.05, 0.08, and 0.08 respectively. The biological attributes like population build-up, grain damage, weight loss, and orientation in the free choice test were minimum in the resistant varieties. In paddy, grain hardiness varied from 83.67 to 128.00 N and conferred resistance to the variety. The carbohydrate, protein, and phenol content of paddy varieties ranged from 64.32 to 78.03 per cent, 6.17 to 9.33 per cent, and 1.17 to 0.157 mg/g respectively. The correlation matrix showed that the susceptibility index had strong positive correlations with carbohydrate (r = 0.691**) and protein (r = 0.599**) and a strong negative correlation with phenol content (r = -0.762**). In wheat, based on the susceptibility index two varieties, viz., DBW303 (1.96