Deciphering Host Preference and Resistance of Basmati Rice Varieties against Sitophilus oryzae (L.) (Coleoptera: Curculionidae)

Abstract

Sitophilus oryzaeis a significant and devastating pest of stored cereal grains such as rice, wheat, barley and maize, causes damage to about 10-80 % under prolonged suitable conditions. The research investigation on host preferences of Sitophilus oryzae in unhusked rice, husked rice, barley, wheat, maize, and eight basmati rice varieties. Parameters such as adult emergence (AE), median development period (MDP), growth index (GI), susceptibility index (SI), grain weight loss (%), and grain damage (%) were evaluated. Experiment revealed that the rate of adult emergence was higher in unhusked rice signifying the suitability of the host over maize followed by barley, wheat, and husked rice. Among all basmati rice varieties tested PB-1509 (SI=4.81) showed moderate resistance compared to other varieties. Positive significant correlations were observed among SI and adult emergence (r = 0.967), growth index (r = 0.968), grain weight loss (r = 0.945), and grain damage (r=0.841) but it showed a negative significant correlation with median developmental time (r = − 0.696) indicating that resistance mechanisms can prolong developmental periods, reduce pest generations, and limit damage. These findings emphasize the importance of incorporating resistance traits into breeding programs to enhance storage stability and minimize post-harvest losses in Basmati rice-growing regions.