混合蚜虫斑块对食蚜瘿蚊繁殖力的影响

食蚜瘿蚊是多种蚜虫的捕食性天敌.深入研究影响该虫繁殖力的关键性因子有助于改进规模化饲养以及提高该虫在生物防治中的应用效果.本文选用玉米蚜、禾谷缢管蚜和麦长管蚜作为寄主昆虫,通过设置猎物蚜虫斑块的3种混合方式(单一种群、两种或三种均匀混合种群),以及每种混合方式下的4个密度梯度(总虫量6～48头/株),研究混合蚜虫斑块对...

Effects of Mixed Aphid Patches on Fecundity of Aphidoletes aphidimyza (Diptera: Cecidomyiidae)

Aphidoletes aphidimyza (Rondani) is an important predatory natural enemy of many aphid species. Understanding the key factors influencing the predator's fecundity will contribute to the improvement of the mass production and application of A. aphidimyza in biological control. Here, we measured the fecundity of A. aphidimyza fed with three aphid species, Rhopalosiphum maidis Fitch, Rhopalosiphum padi Fitch, or Sitobion avenae Fabricius, individually or an equal mixture of 2 or 3 aphid species at 4 densities of 6 to 48 aphids/plant. The results showed that, regardless of individual species or in an equal mixture of 2 or 3 species, the lifetime fecundity of A. aphidimyza increased with the addition of aphid densities, significantly different between the 4 densities. The highest fecundity was observed at prey densities of 24 to 48 aphids/plant. When confined to the same prey density, A. aphidimyza deposited the fewest when provided with individual species of prey and the most when provided with a mixture of 3 species of prey. These results suggest that lifetime fecundity of A. aphidimyza is dependent on both density and species of prey. The higher density and more prey aphid species in a mixture are beneficial for high fecundity in A. aphidimyza.