Vargas Roger I, Long Jay, Miller Neil W, Delate Kathleen, Jackson Charles G, Uchida Grant K, Bautista Renato C, Harris Ernie J
U.S. Pacific Basin Agricultural Research Center, USDA-ARS, P.O. Box 4459, Hilo, HI 96720, USA.
J Econ Entomol. 2004 Oct;97(5):1531-9. doi: 10.1603/0022-0493-97.5.1531.
Ivy gourd, Coccinia grandis (L.) Voigt, patches throughout Kailua-Kona, Hawaii Island, HI, were identified as persistent sources of melon fly, Bactrocera cucurbitae (Coquillett). These patches had a low incidence of Psyttalia fletcheri (Silvestri), its major braconid parasitoid natural enemy in Hawaii, and were used to evaluate augmentative releases of P. fletcheri against melon fly. In field cage studies of releases, numbers of melon flies emerging from ivy gourd fruit placed inside treatment cages were reduced up to 21-fold, and numbers of parasitoids were increased 11-fold. In open field releases of P. fletcheri into ivy gourd patches, parasitization rates were increased 4.7 times in release plots compared with those in control plots. However, there was no significant reduction in emergence of melon flies from fruit. In subsequent cage tests with sterile melon flies and P. fletcheri, combinations of sterile flies and P. fletcheri produced the greatest reduction (9-fold) in melon fly emergence from zucchini, Cucurbita pepo L. Reductions obtained with sterile flies alone or in combination with parasitoids were significantly greater than those in the control, whereas those for parasitoids alone were not. Although these results suggest that the effects of sterile flies were greater than those for parasitoids, from a multitactic melon fly management strategy, sterile flies would complement the effects of P. fletcheri. Cost and sustainability of these nonchemical approaches will be examined further in an ongoing areawide pest management program for melon fly in Hawaii.
夏威夷岛凯卢阿 - 科纳各地的蛇瓜（Coccinia grandis (L.) Voigt）地块被确定为瓜实蝇（Bactrocera cucurbitae (Coquillett)）的持续来源。这些地块中夏威夷瓜实蝇的主要茧蜂寄生天敌弗莱氏浆角蚜小蜂（Psyttalia fletcheri (Silvestri)）的发生率较低，并被用于评估对瓜实蝇进行弗莱氏浆角蚜小蜂的增殖释放效果。在释放的田间网笼试验中，放置在处理笼内的蛇瓜果实中羽化出的瓜实蝇数量减少了多达21倍，寄生蜂数量增加了11倍。在将弗莱氏浆角蚜小蜂释放到蛇瓜地块的田间试验中，与对照地块相比，释放地块的寄生率提高了4.7倍。然而，果实中瓜实蝇的羽化率没有显著降低。在随后用无菌瓜实蝇和弗莱氏浆角蚜小蜂进行的网笼试验中，无菌瓜实蝇和弗莱氏浆角蚜小蜂的组合使西葫芦（Cucurbita pepo L.）中瓜实蝇的羽化率降低幅度最大（9倍）。单独使用无菌瓜实蝇或与寄生蜂组合使用时获得的降低幅度显著大于对照，但单独使用寄生蜂时则不然。尽管这些结果表明无菌瓜实蝇的效果大于寄生蜂，但从瓜实蝇多策略管理策略来看，无菌瓜实蝇将补充弗莱氏浆角蚜小蜂的效果。在夏威夷正在进行的瓜实蝇区域害虫管理计划中，将进一步研究这些非化学方法的成本和可持续性。
