食蚜瘿蚊捕食能力研究

食蚜瘿蚊Aphidoletes aphidimyza(Rondani)是多种蚜虫的重要天敌,在农业生产中具有重要的应用潜力。为研究食蚜瘿蚊幼虫对玉米蚜Rhopalosiphum maidis(Fitch)的搜寻和控害潜能及饥饿胁迫对其捕食行为的影响,在室内条件下研究了食蚜瘿蚊各龄期幼虫对玉米蚜的捕食量;3龄幼虫饥饿24 h后的捕食速度;各龄幼虫饥饿12 h后的爬行能力;各龄幼虫耐饥饿能力及3龄幼虫不同饥饿程度下的捕食功能反应。结果表明,食蚜瘿蚊3龄幼虫的捕食量最大,总共19.21头;2和3龄幼虫的爬行速度较快,田间觅食能力较强。不同饥饿程度的食蚜瘿蚊3龄幼虫对玉米蚜的捕食功能反应拟合HollingⅡ型功能反应模型,其捕食量均随蚜虫密度的增加而上升。综上所述,食蚜瘿蚊2龄末3龄初的幼虫具有较强的捕食和耐饥饿能力。

Predatory Capacity of Aphidoletes aphidimyza (Rondani)

Aphidoletes aphidimyza (Rondani),an important predator of many aphids,has important potential applications in agricultural production.To clarify the potential of A.aphidimyza larvae for control of Rhopalosiphum maidis (Fitch),the predatory amount,crawling ability and starvation tolerance of the predator were evaluated.The results showed that the predatory amount ofA.aphidimyza 3rd instars was 19.21,higher than that of the other instars.The crawling speed and field foraging ability ofA.aphidimyza 2nd and 3rd instars were stronger than the other instars.The functional responses of A.aphidimyza 3rd instars suffered from different degree ofstarvation to R.maidis could be fitted to Holling Ⅱ formula,and the predatory capacities enhanced with increasing prey density.The results indicate that the late 2nd instars and early 3rd instars,with strong predation and starvation tolerance capability,can offer better control against R.maidis.