Biology of cashew stem and root borer, Plocaederus ferrugineus L. on different hosts*

The cashew stem and root borer (CSRB) successfully completed its life cycle in three host plants, viz., cashew (Anacardium occidentale), drumstick (Moringa oleifera) and silk cotton (Ceiba pentandra) to the tune of 80.9%, 58.6% and 57.5% respectively. The female adult completed its life cycle in 252.2 ± 6.3 days in cashew, 215.2 ± 17.2 days in silk cotton and 205.0 ± 20.6 days in drumstick. Egg hatchability was observed to be highest in cashew (98%) followed by silk cotton (90%) and drumstick (85%). Mortality of the 1^st instar grub was the lowest (9.2%) in cashew followed by drumstick (12.2%) and silk cotton (15.2%). Six grub instars were observed. The rate of pupation, adult emergence and fecundity/female was higher on cashew than on drumstick and silk cotton.