Different preys affecting biology and life table parameters of Exochomus nigripennis (Erichson) (Col.: Coccinellidae): prospects for augmentative biological control of sucking pests

The development and reproductive capacities of the ladybird, Exochomus nigripennis (Erichson) (Col.: Coccinellidae), were conducted in the laboratory conditions on three preys. The differences in immature developmental periods on various preys tested were significant, being longest on A. pistaciae and shortest on Ephestia kuehniella eggs. Male and female adults fed on Agonoscena pistaciae lived longer than the predators fed other preys. Also, the oviposition period was at the longest level for females reared on E. kuehniella eggs and at the shortest level for A. pistaciae. Significantly, more eggs were oviposited on A. pistaciae than on E. kuehniella eggs and Gossyparia spuria. The highest and lowest net reproductive rate (R-0) values were for the predators fed on A. pistaciae and E. kuehniella eggs, respectively. The E. nigripennis fed on E. kuehniella eggs had the highest value of the intrinsic rate of increase (r(m)). In contrast, the lowest r(m) value was obtained when predators fed on A. pistaciae. Similarly, the finite rate of increase (lambda) was highest on E. kuehniella eggs and lowest on A. pistaciae. The mean population generation time ranged from 42.5 days on E. kuehniella eggs to 59.6 days on A. pistaciae. Our findings suggest that E. nigripennis can be highly efficient for controlling A. pistaciae. Also, E. kuehniella eggs could be more useful for mass rearing of E. nigripennis to use in integrated pest management program of sucking pests.