Biology and management of mealybug, Paracoccus marginatus Williams and Granara de Willink on Jatropha curcas L.

Abstract

Jatropha cultivation is gaining importance as potential source of biofuel. Recently Paracoccus marginatus has been found to cause serious damage on Jatropha. Studies on the biology and management of P. marginatus at GKVK, Bangalore revealed that the females had three nymphal instars without any pupal stage, while the male had three nymphal instars besides, pre-pupal and pupal stages. The total nymphal period for female ranged from 14 to 21 days, (mean- 17.32±1.6 days) while for male the range was 16 to 23 days, (mean- 18.9±1.3 days). Bisexual and parthenogenetic modes of reproduction were observed. The fecundity of the female mealybug ranged from 248 to 967, with an average of 618.9±19 eggs. Evaluation of insecticides revealed that during first spray and second spray, mean per cent reduction of mealy bug population was highest in profenophos 0.05% (68.05 and 79.35) followed by buprofezin 0.025% (63.61 and 72.69). Least per cent reduction of mealy bug was observed in the NSKE 5% (17.94 and 25.77) treatment.