Yee Wee L, Goughnour Robert B, Hood Glen R, Forbes Andrew A, Feder Jeffrey L
United States Department of Agriculture, Agricultural Research Service, Yakima Agricultural Research Laboratory, 5230 Konnowac Pass Rd., Wapato, WA 98951.
Washington State University Extension, 1919 NE 78th St., Vancouver, WA 98665.
Environ Entomol. 2015 Aug;44(4):1029-42. doi: 10.1093/ee/nvv097. Epub 2015 Jul 1.
The western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), is an endemic herbivore of bitter cherry, Prunus emarginata (Douglas ex Hooker) Eaton, but ∼100 years ago established on earlier-fruiting domesticated sweet cherry, Prunus avium (L.) L. Here, we determined if eclosion times of adult R. indifferens from sweet and bitter cherry differ according to the phenology of their respective host plants and if eclosion times of the host-specific parasitoid Diachasma muliebre (Muesebeck) (Hymenoptera: Braconidae) attacking bitter and sweet cherry flies differ according to the eclosion phenology of their fly hosts. Fly pupae from sweet and bitter cherry fruit were collected from sympatric and allopatric sites in Washington state, and chilled at 5°C. Because timing of eclosion in R. indifferens depends on chill duration, eclosion time in wasps could also vary with chill duration. To account for this, fly pupae were chilled for 1, 2, 2.5, 3, 4, 6, or 8 mo. Both flies and wasps eclosed earlier with longer chill durations. Eclosion times of sweet and bitter cherry flies from a sympatric site in central Washington did not differ. However, at allopatric sites in northwestern and central Washington, bitter cherry flies eclosed later than sweet and bitter cherry flies at the sympatric site. Correspondingly, D. muliebre parasitizing a more isolated bitter cherry fly population eclosed later than D. muliebre parasitizing earlier-emerging sweet and bitter cherry fly populations. These results provide evidence for D. muliebre rapidly responding to changes in host plant shifts by R. indifferens.
西部樱桃实蝇（Rhagoletis indifferens Curran，双翅目：实蝇科）是苦樱桃（Prunus emarginata (Douglas ex Hooker) Eaton）的一种地方性植食性昆虫，但约100年前它在更早结果的驯化甜樱桃（Prunus avium (L.) L.）上定殖。在此，我们确定了来自甜樱桃和苦樱桃的成年西部樱桃实蝇的羽化时间是否根据其各自寄主植物的物候而有所不同，以及攻击甜樱桃和苦樱桃实蝇的寄主特异性寄生蜂穆氏潜蝇茧蜂（Diachasma muliebre (Muesebeck)，膜翅目：茧蜂科）的羽化时间是否根据其果蝇寄主的羽化物候而有所不同。从华盛顿州的同域和异域地点收集甜樱桃和苦樱桃果实中的果蝇蛹，并在5°C下冷藏。由于西部樱桃实蝇的羽化时间取决于冷藏持续时间，寄生蜂的羽化时间也可能随冷藏持续时间而变化。为了考虑这一点，将果蝇蛹冷藏1、2、2.5、3、4、6或8个月。果蝇和寄生蜂的羽化时间都随着冷藏持续时间的延长而提前。来自华盛顿州中部同域地点的甜樱桃和苦樱桃实蝇的羽化时间没有差异。然而，在华盛顿州西北部和中部的异域地点，苦樱桃实蝇的羽化时间比同域地点的甜樱桃和苦樱桃实蝇晚。相应地，寄生在更孤立苦樱桃实蝇种群上的穆氏潜蝇茧蜂的羽化时间比寄生在较早羽化的甜樱桃和苦樱桃实蝇种群上的穆氏潜蝇茧蜂晚。这些结果为穆氏潜蝇茧蜂对西部樱桃实蝇寄主植物转移变化的快速响应提供了证据。
