寄主密度对玉米螟赤眼蜂寄生及繁衍能力的影响

Effect of Host Density on Parasitism and Reproduction in Trichogramma ostriniae

[目的]探讨寄主密度对玉米螟赤眼蜂寄生及繁衍能力的影响,为玉米螟赤眼蜂饲养技术的优化改良及其田间释放提供参考。[方法]采用卡方检验及回归分析对不同寄主密度下单头玉米螟赤眼蜂的寄生卵数、产卵数、产雌数、出蜂率和单卵出蜂数进行了研究。[结果]玉米螟赤眼蜂寄生卵数、产卵数及产雌数不会随着接卵量的增加而同等倍数的增长,寄主密度阈值为90粒/管;单卵出蜂数随着寄主密度增大而减少,当玉米螟赤眼蜂与接卵量之比为1∶160时可减少过寄生现象产生;寄主密度对玉米螟赤眼蜂的出蜂率无显著性影响。[结论]寄主密度能不同程度地影响玉米螟赤眼蜂的寄生、产卵及出蜂情况,在进行玉米螟赤眼蜂室内繁育及田间控害操作时需要特别留意寄主密度的选择,以增强其寄生及繁衍能力。

[Objective] The aim was to figure out the effect of host density on parasitism and reproduction in T.ostriniae,provide reference for optimization and field release of T.ostriniae breeding technology.[Method]Chi-squre test and regression analysis were used to study parasite count,eggs laid count,female offspring count,emergence rate and emergence count per host egg under different host density in T.ostriniae.[Result] The results showed that parasite count,eggs laid count and female offspring count could not increase in proportion with the raising host density,and the host density threshold was 90.Emergence count per host egg decreased with the raising host density,and the optimal proportion between the number of parasite and host was 1∶ 160 for reducing super parasitism.Host density had no significant effect on emergence rate in T.ostriniae.[Conclusion]Host density could affect parasitism,laying and emergence in T.ostriniae.Therefore,the choice of host density was particular important for enhancing parasitism and reproduction during rearing indoors or releasing outdoors in T.ostriniae.