The quality assessment of Neoseiulus californicus (Phytoseiidae) reared on thorn apple pollen for 40 generations

Abstract

ABSTRACT The predatory mite Neoseiulus californicus (McGregor) is an important biological control agent used to control some phytophagous mites. Developmental times, survival, and fecundity of this predator were assessed when fed on thorn apple (Datura stramonium L.) pollen grains over 40 sequential generations from G1 (reared on pollen in first generation) to G40 (reared on pollen for 40 generations). The predatory mites were obtained from a colony maintained for five generations on the two-spotted spider mite (TSSM) (Tetranychus urticae Koch) as prey. The predation capacity of the predatory mite on two-spotted spider mite was assessed in G1TSSM (without rearing on pollen) and G40TSSM (reared on pollen for 40 generations before transfer on T. urticae). The total developmental time of N. californicus varied among different generations, but there was no regular trend in the performance of the predatory mite reared over generations despite differences in population growth parameters. The intrinsic rate of increase (r) ranged from 0.156 day–1 in G2 to 0.229 day–1 in G20. The net predation rate (C 0), stable predation rate (), finite predation rate (), and transformation rate (Qp) of N. californicus on nymphal stages of the two-spotted spider mite showed no significant difference in G1TSSM and G40TSSM period. So, the quality of N. californicus reared on thorn apple pollen after 40 generations remained constant; indicating this pollen can be used as a suitable and cost-effective food source for the long-term rearing of N. californicus.