两种蚜小蜂对烟粉虱寄主的产卵选择性（英文）

双斑恩蚜小蜂和桨角蚜小蜂是华南地区烟粉虱的两种优势种寄生蜂。本文研究了两种寄生蜂对不同龄期烟粉虱寄主的产卵选择特性。结果表明: 两种寄生蜂均可寄生烟粉虱的1～4龄若虫。当只有1个龄期的烟粉虱若虫存在时，双斑恩蚜小蜂更多地寄生3龄和4龄若虫，较少寄生1龄和2龄若虫；而桨角蚜小蜂则更多地寄生3龄和2龄若虫，较少寄生1龄和4龄若虫。在4个龄期若虫同时存在时，双斑恩蚜小蜂会明显增加对3龄和4龄若虫的产卵寄生，降低对1龄和2龄若虫的寄生；而桨角蚜小蜂则增加对2龄和3龄若虫的寄生，减少对1龄和4龄若虫的寄生。寄主植物的差异不影响这二种蚜小蜂对各龄期烟粉虱若虫的产卵选择倾向。结果提示，烟粉虱若虫3龄和4龄是双斑恩蚜小蜂最适宜的寄主，而桨角蚜小蜂最适宜的寄主是烟粉虱2龄和3龄若虫。

Oviposition preference of Encarsia bimaculata and Eretmocerus sp. nr. furuhashii (Hymenoptera: Aphelinidae), two parasitoids of Bemisia tabaci (Hemiptera: Aleyrodidae)

Encarsia bimaculata and Eretmocerus sp. nr. furuhashii are two dominant species of parasitoid parasitizing Bemisia tabaci in South China. Oviposition preference of the two species was studied in the laboratory. The results indicated that both the two species of wasps could parasitize all nymphal stages of B. tabaci. When given a single instar nymphs of B. tabaci, E. bimaculata lay more eggs on the 3rd and 4th instar nymphs than on the 1st and 2nd instars, while Er. sp. nr. furuhashii lay more eggs on the 3rd and 2nd instars than on the 1st and 4th instars. When given all four B. tabaci instars simultaneously, E. bimaculata decreased the parasitization on the 1 st and 2nd instar nymphs but increased the parasitization on the 3rd and 4th instar immatures; whereas Er. sp. nr. furuhashii increased its parasitization on the 2nd and 3rd instars but reduced oviposition on the 1st and 4th instars. Host plants showed no influence on the oviposition trends of the two wasps. The results suggested that the 3rd and 4th instar nymphs of B. tabaci were the most suitable hosts for E. bimaculata while the 2nd and 3rd instars were the more suitable for Er. sp. hr. furuhashii.