瓢虫柄腹姬小蜂各虫态低温贮存和寄生效应的研究

STUDIES ON THE COLD STORAGE AND FUNCTIONAL RESPONSE OF PEDIOBIUS FO VEOLA TUS (CRAWFORD) (HYMENOPTERA: EULOPHIDAE)

瓢虫柄腹姬小蜂Pediobius foveolatus(Crawford)不同虫态在5℃,8℃,11℃下,蜂卵和蜂幼不能贮存。蜂蛹在该温度范围内,随温度升高而羽化率上升,随贮存时间延长而羽化率下降。成蜂在8℃,11℃,14℃下贮存10 d,雌蜂的产卵能力、寄生幼虫数、寄生率与对照相比无显著差异。贮存18 d后,蜂的产卵能力明显下降,25 d后无寄生蜂羽出。随着寄主密度的提高,每头雌蜂对寄主的寄生数没有明显变化,在相同的寄主密度条件下,寄生蜂单雌寄生数有随其自身密度增加而下降的趋势,但变量分析的结果表明,在各密度下的每雌寄生数没有显著差异,随着两者密度的增加,相互干扰作用越明显,寄生作用率下降。

Cold storage at constant temperature of 5℃, 8℃, 11℃, the egg and the larvae of the parasite, Pediobius .foveolatus(Crawford), could not be stored. The results showed that the emergence rate of the pupa was correlated positively with the storage temperature, and correlated negatively with the length of storage duration. When the adults were stored at 8℃, 11℃ and 14℃ for 10 days, the capability of oviposition and parasitization were not significantly different from that of non-stored adult wasps in the control. Functional response of P. foveolatus to parasite density belonged to the model of watt. The results showed that the parasitical capability decreased with the increase in the parasite density, but no functional response to host density, when the numbers of parasite and host increased. The interference became significant, resulting in the decrease in the rate of parasitization.