ABSTRACT

The squash bug, Anasa tristis (De Geer) is a serious pest of cucurbit crops. The egg parasitoid, Gryon pennsylvanicum (Ashmead), is the primary parasitoid of the squash bug and has been considered as a biological control agent. In the present study, we conducted both laboratory and greenhouse bioassays to determine the effects of kairomones emitted by A. tristis on the host searching behaviour of G. pennsylvanicum. Chemicals were extracted from A. tristis eggs, unmated females and males, and mated females and males. The percentage of females responding to extracts was significantly higher for egg extracts than the other extracts tested. In greenhouse tests, percent parasitism of egg masses baited with extract-treated lures was significantly higher than for those treated with solvent-treated control lures for all six extracts tested: ethanol and hexane extracts of eggs, mated females and mated males. Further research on kairomones of A. tristis may result in the development of synthetic lures that could be used in squash fields to increase parasitism by G. pennsylvanicum. The promising results from this study highlights the potential application of kairomones in enhancing the efficacy and effectiveness of biological control programmes and should be of interest to growers and pest control professionals.

摘要

南瓜虫Anasa tristis (De Geer) 是葫芦科作物的严重害虫。卵寄生物Gryon pennsylvanicum (Ashmead) 是壁球虫的主要寄生物，被认为是一种生物防治剂。在本研究中，我们进行了实验室和温室生物测定，以确定A. tristis释放的 kairomones对G. pennsylvanicum宿主搜索行为的影响。从A. tristis中提取化学品卵，未交配的雌性和雄性，以及交配的雌性和雄性。对于鸡蛋提取物，雌性对提取物的反应百分比显着高于其他测试提取物。在温室试验中，对于所有六种测试提取物：用乙醇和己烷提取的鸡蛋、交配雌性和交配雄性，用提取物处理过的诱饵诱饵的卵块的寄生百分比显着高于用溶剂处理过的对照诱饵处理的那些。对A. tristis 的kairomones 的进一步研究可能会导致开发可用于壁球地以增加G. pennsylvanicum寄生的合成诱饵. 这项研究的有希望的结果突出了 kairomones 在提高生物防治计划的功效和有效性方面的潜在应用，应该引起种植者和害虫防治专业人员的兴趣。