Suitability of webworm Loxostege sticticalis L. (Lepidoptera: Crambidae) eggs for consumption by immature and adults of the predatory mite Neoseiulus pseudolongispinosus (Xin, Liang and Ke) (Acarina: Phytoseiidae)

摘要

The genus Loxostege has a worldwide distribution and includes an economically important group of insect pests of different crops. The effectiveness of predator Neoseiulus pseudolongispinosus (Xin, Liang and Ke) as a potential bio-control agent of webworm Loxostege sticticalis L., was investigated by measuring rates of prey consumption and destruction by the different life stages of mite, duration and viability of immature, pre-oviposition and oviposition periods, total oviposition capacity, and longevity of adults. When eggs food was offered in similar amounts, there were variations in consumption tendency among the different life stages of predator. Mean development period was shortest for egg-fed larvae, whereas, longest in deutonymph followed by egg and protonymph, and total life cycle was completed in a mean of 12.75 days for male or female. A mean pre-oviposition period of 4.28 days was recorded in female and period of oviposition lasted for 8.71 days. The mean number of eggs recorded was 1.42 day-1 female-1. Mortality was recorded in all life stages and percent viability was best in egg stage, adult females and males, and slightly less in larvae, protonymphs and deutonymphs. Further, predatory activity of mites, such as their feeding habits, number of eggs damaged, how they were damaged and oviposition were observed. It is concluded that N. pseudolongispinosus can be successfully reared on L. sticticalis eggs, which proved a good food for adults and nymphs. Laboratory data indicated that this predatory mite has the potential to act as a biological control agent of L. sticticalis in crops.