Effects of Prey Species and Host Plants on Development and Life History of Stethorus gilvifrons (Coleoptera: Coccinellidae)

Stethorus gilvifrons (Mulstant) is an important voracious predator of the spider mites, which consumes all the life stages of spider mites. In this study, the effects of prey species and host plants on development and life table parameters of S. gilvifrons were studied. To this end, preimaginal development, survival, adult longevity and fecundity of S. gilvifrons fed on Tetranychus urticae Koch (on maize and cowpea) and Eutetranychus orientalis Klein (on castor bean plants) were studied. Experiments were conducted based on two-sex life table procedure under laboratory conditions at 27 +/- 1 degrees C, 60-70% RH and 16:8 hours L:D. The shortest developmental time and female longevity were recorded on maize and cowpea, respectively, and the longest was on castor bean. While the lowest values of fecundity, net Reproductive rate (R-0) and intrinsic rate of increase (r) were estimated at 107.65 +/- 11.49 offspring, 20.63 +/- 4.41 offspring and 0.1001 +/- 0.0072 d(-1) on castor bean, respectively, the highest values of the mentioned parameters were 158.67 +/- 20.18 offspring, 43.63 +/- 8.47 offspring, and 0.1448 +/- 0.0069 d(-1) on maize, respectively. The results proved the significant effects of the host plants and prey species on developmental time and demographic parameters of S. gilvifrons. The obtained results could be useful for mass rearing of S. gilvifrons and for better understanding of its population dynamics in relation to the prey species and host plants.