海氏桨角蚜小蜂新疆种群形态特征及其与烟粉虱的时空动态比较

为了解烟粉虱的寄生蜂海氏桨角蚜小蜂的特征、发生规律,观察了其新疆种群的形态特征,于2012年在田间比较了该寄生蜂在棉花、甜瓜、茄子和辣椒上与烟粉虱的时空动态。结果表明,在辣椒上海氏桨角蚜小蜂成虫发生期最早,7月5日始见成虫;在4种作物上海氏桨角蚜小蜂和烟粉虱成虫分别在茄子和甜瓜上的发生数量最多,单叶虫口数量最高分别为16.12和66.47头;除辣椒外,在其它作物上成蜂的发生期比烟粉虱成虫约晚20 d,而被寄生的烟粉虱若虫与未被寄生的若虫时空动态较吻合;烟粉虱和海氏桨角蚜小蜂在植株上的成虫数量均表现出明显的上部中部下部的分布特征。研究表明,与烟粉虱比较,海氏桨角蚜小蜂新疆种群的时空动态表现出明显的滞后性和跟随效应,且其可能对寄主植物有一定的选择性。

The morphological characteristic observation of Eretmocerus hayati and the comparison of its temporal and spatial dynamic with Bemisia tabaci

To clarify the characteristics and occurrence of Eretmocerus hayati, the parasitoid of Bemisia tabaci, the morphological characteristics of E. hayati were observed in the laboratory, and the population temporal and spatial dynamics of B. tabaci and E. hayati populations on Gossypium hirsutum L., Cucumis melo L., Solanum melongena L. and Capsicum annuum L. were investigated and compared in the field in 2012. The results showed that the occurrence period of E. hayati on C. annuum was earlier than on the other plants, and adults emerged on July 5th. On the four crops, the numbers of E. hayati adults and B. tabaci adults were the highest on S. melongena and C. melo with the number of 16.12 and 66.47 individuals/leaf, respectively. E. hayati adults occurred 20 d later than B. tabaci adults, however, the temporal and spatial dynamics of B. tabaci nymphs and the nymphs parasitized by E. hayati were quite coincident. The numbers of E. hayati adults and B. tabaci adults were larger on the upper parts of the plant than on the middle and lower parts. The results indicated that, compared with B. tabaci population, the temporal and spatial dynamics of E. hayati populations showed distinct lag and following effect, and the wasp probably showed a certain degree of selectivity to host plants.