Abstract

Amblyseius tsugawai is a phytoseiid species distributed in Asia. In the present study, laboratory experiments were conducted to investigate its preference to prey stages when feeding on Tetranychus urticae and Bemisia tabaci, to evaluate its development and reproduction, and to estimate its life table parameters on each of the two prey species. Our results indicate that A. tsugawai shows preference to larvae of T. urticae, and to eggs of B. tabaci. When the two preferred stages were provided together, A. tsugawai randomly selected its prey. No significant difference in developmental times of A. tsugawai was observed when reared on T. urticae (6.75 days) and B. tabaci (7.05 days). In contrast, cumulative fecundity of A. tsugawai was only 14.6% when reared on B. tabaci (4.6 eggs/female) than on T. urticae (31.5 eggs/female). Impact of prey for both females and males on reproduction were also observed. Comparing to the treatment when both parents were reared on T. urticae, A. tsugawai fecundity was reduced by ca. 48.2% when the male was reared on B. tabaci, and was reduced by 86.5% and 88.8% when the female or both parents were reared on B. tabaci, respectively. Amblyseius tsugawai is the first indigenous phytoseiid species of China to show a positive intrinsic rate of population increase (0.013) when reared on B. tabaci as the only prey. The potential of A. tsugawai in greenhouse whitefly control is discussed.