切割潜蝇茧蜂对桔小实蝇幼虫功能反应研究

The Functional Response and Disturbance Response of Larvae of Psyttalia incisi (Silvestri) to Oriental Fruit Flies

在切割潜蝇茧蜂对桔小实蝇幼虫寄生的过程中,供试寄主幼虫密度对切割潜蝇茧蜂的寄生作用有明显的影响。当供试寄主幼虫处于低密度(<30头/果片)时,被寄生的幼虫数随自身密度的增加而增加;当幼虫密度≥30头/果片时,被寄生的幼虫数量增幅急剧变小而接近极限水平,与切割潜蝇茧蜂的生殖极限有关。采用HollingⅡ模型进行拟合,其功能反应模型为Na=0.560 8Nt/(1+0.011 89Nt);切割潜蝇茧蜂自身的密度对寄生作用也有一定程度的影响,符合Hassell-Varley模型a=2.073Pt-1.824 4,表明切割潜蝇茧蜂的发现域随着自身密度的增加而逐渐变小,寄生蜂个体间的相互干扰效应降低了寄生效能。

The density of the host larvae -oriental fruit fly affected the parasitic effect of P. incisi significantly, which accorded with the Holling Ⅱ Equation：N = 0. 560 8N1/（ 1 ＋ 0.011 89N1）. The more host larvae provided, the more larvae were parasitized, hut the increasing extent was getting smaller when the host density was no more than thirty per slice of guava, while the increasing extent was getting much smaller when the host density was more than thirty per slice of guava. What＇ s more, the density of P. incisi also affected the parasitic effect which accorded with Hassell - Varley Equation a = 2. 073P,-＇s244. The more P. incisi provid- ed, the less larvae were searched by parasitoids because of some interference acts of individuals.