浅黄恩蚜小蜂与丽蚜小蜂的种间竞争及其对粉虱控制作用的影响

【目的】明确浅黄恩蚜小蜂（Encarsia sophia）与丽蚜小蜂（E. formosa）的种间竞争及其对粉虱控制作用的影响。【方法】以番茄为寄主植物，温室白粉虱为寄主昆虫，浅黄恩蚜小蜂与丽蚜小蜂以10 : 0、8 : 2、5 : 5、2 : 8及0 : 10进行混合释放，每20 d抽样1次，调查浅黄恩蚜小蜂、丽蚜小蜂及粉虱的种群动态变化。【结果】2种寄生蜂以不同比例混合释放60 d后，丽蚜小蜂在寄生蜂中的百分率始终保持在50%左右；不同比例混合释放或单独释放，均能将粉虱种群数量控制在较低的水平，特别是5 ES﹕5 EF混合释放后，通过寄生和取食杀死粉虱的百分率始终高于83%，对温室白粉虱表现出长期稳定的控制效果。【结论】在温室白粉虱作为重要寄主时，浅黄恩蚜小蜂并不能竞争取代丽蚜小蜂，浅黄恩蚜小蜂的存在没有干扰粉虱的防治效果。

Interspecific Competition Between Encarsia sophia and E. formosa and Their Impacts on Suppression of Trialeurodes vaporariorum

【Objective】The objective of this study is to determine the potential of Encarsia sophia, a heteronomous hyperparasitoid, replacing primary parasitoids that share the same hosts and disrupting whitefly suppression in combination with primary parasitoids E. formosa. 【Method】 In this study, E. sophia and the primary parasitoid, E. formosa were released at ratios of 10﹕0, 8﹕2 , 5﹕5, 2﹕8 and 0﹕10 for controlling the greenhouse whitefly, Trialeurodes vaporariorum, on tomato. After releasing, the population dynamics of E. sophia, E. formosa and T. vaporariorum were investigated every 20 d.【Result】The percentage of E. formosa in total parasitoids was always kept about 50% sixty days after both parasitoids were released at different ratios. Releases of any one parasitoid species only or both of the parasitoids at different ratios provided low levels of whitefly population. Especially, the population of T. vaporariorum was always effectively suppressed with more than 83% whiteflies killed by parasitism and host feeding after E. sophia and E. formosa were released at a ratio of 5﹕5.【Conclusion】The heteronomous hyperparasitoid (E. sophia) can’t replace the primary parasitoid (E. formosa) on T. vaporariorum. The competitive interactions between the two parasitoid species do not reduce the efficiency of whitefly suppression.