Biology of an egg parasite of Callosobruchus maculatus (Fab.) (Coleoptera: Bruchidae)

Uscana mukerjii (Mani) (Chalcidoidea, Trichogrammatidae) parasitizes eggs of Callosobruchus maculatus. Mated adult U. mukerjii lived for 5.0 ± 0.8 and 4.7 ± 0.9 days (males and females, respectively) at 27 °C. The female copulated only once, whereas males did so up to 4 times. The maximum parasitization of host eggs took place within the first 24 hours of egg laying and declined thereafter. The parasite completed its development inside the host egg in 7.2 days at 27 °C and 60–63% r.h. and emerged after cutting a circular hole in the chorion of the host egg. Mated and unmated females laid 35.4 ± 1.4 and 36.0 ± 2.2 eggs in their life time of which 27.3 ± 1.8 and 23.2 ± 2.8, hatched respectively. Parasitized host eggs did not hatch and were ultimately destroyed. The degree of parasitization varied with the pulses on which the host eggs were laid. This egg parasite may be useful in controlling the populations of C. maculatus and thus help in reducing the damage caused.