Role of hosts in the biology and life table development of Henosepilachna vigintioctopunctata (Fab.)

Abstract

Hadda beetle, Henosepilachna vigintioctopunctata (Fab.), a polyphagous pest of vegetables, is widely distributed throughout the world. Both grub and adult are common pest of solanaceous and cruciferous vegetables in West Bengal, India. In the present study, three host plant species viz., brinjal, Solanum melongena L. (cv Pusa purple long), potato, Solanum tuberosum L. (cv Chandramukhi) and bitter gourd, Momordica charantia (cv. Coimbatore long) were used to study their role in the biology and life table development of this insect. Oviposition period, fecundity, survival % of grub and longevity of adults were higher in brinjal, as compared to potato and bitter gourd due to their nutritional differences which influenced the insect growth and reproduction. The studies on variation of sex ratio indicated that, a greater number of female progenies were produced from the adults emerged out from brinjal followed by potato and bitter gourd. Consequently, total grub period on brinjal was shorter than on other two hosts. The net fecundity rate (Ro), intrinsic rate of increase (rm), gross reproductive rate (ð›´mx), generation time (Tc), doubling time (DT) and finite rate of increase (ðºm) were also higher in brinjal compared to potato and bitter gourd.