Studies on developmental biology of lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera, Bostrichidae) at different seasons on paddy

Abstract

Developmental biology of Rhyzopertha dominica (F.) (Coleoptera, Bostrichidae) was conducted using the paddy variety RNR-15048 across three seasons: the rainy season, winter season and summer season. The results indicated that the highest and lowest fecundity was observed during the rainy season and summer seasons 200-220 eggs and 46-57 eggs per female, respectively. The longest egg period was found in winter with a mean of 7.80±0.77 days, while the shortest duration was observed with a mean of 4.53±1.33days in summer. The grub and pupal period were longest in winter with an average of 75.33±7.00 days, and shortest in summer with an average 35.23±1.74days. The data showed that adult male lesser grain borers take about 69-74 days for egg laying to adult emergence in the winter, and 31-37 days in summer, while adult females require long time of 81-93 days in winter, and 33-39 days in summer.