Studies On Rejuvenescence Of Chouioia Cunea Yang

Chouioia cunea Yang is important wasp as biological control agents which has been commercially applied to against Hyphantria cunea(Drury). But rearing wasps with the same host for several generations, the vitality of the population was declined which reduced control efficiency on H.cunea. This paper studied the rejuvenescence of C. cunea by screening of strong wasps, supplementing nutrition , alternating hosts and breeding resistance wasps , which provide theoretical foundation and technical support for solving the degradation problem in production. The results were summarized as follows:1. The main biological characteristics of C. cunea offspring were researched after the vertical and horizontal treatment of wasps. The developmental duration, numbers, longevity, sex ratio and the parasitism rate of C. cunea offspring were determined. The longevity of wasps treated with vertical 150 cm and horizontal was 2 days longer than control groups.The number, sex ratio and the parasitism rate of wasps treated with vertical 150 cm and horizontal 150 cm reached 5082.5, 5184.6, 42.56:1, 52.90:1, 93.34%, 96.67% respectively. It indicated that wasps activities could be increased by treating with vertical150 cm and horizontal150cm .2. The longevity of wasps fed with10% fructose, 10% sucrose, 10% glucose,10% honey, was extended. The longevity of wasps fed with10% fructose was 2.13 days longer than those fed with water. The longevity and number of C. cunea offspring were both improved by 10% fructose and 10% glucose, the effect of 10% fructose on wasps was best.3. Using natural host, Porthesia xanthocampa , Bombyx mori, Hyphantria cunea and Prodenia litura, reproduced by one generation, the results showed that the parasitism rate and the sex ratio of wasps raised by 27.33%~35% and 32.38%~73.23% respectively.4. The CarE, GST and O-demethylase activities of wasps treated with cypermethrin and avermecti were improved significantly , but only the CarE and GST activities, the CarE activities were improved significantly treated with chlorbenzuron and matrine·nicotine respectively. It stated that the effect of cypermethrin and avermecti were best.