USDA-ARS, Temperate Tree Fruit and Vegetable Research Unit, 5230 Konnowac Pass Road, Wapato, WA 98951, USA.
Washington State University Extension, 404 W. Clark Avenue, Pasco, WA 99301, USA.
Environ Entomol. 2024 Aug 17;53(4):677-686. doi: 10.1093/ee/nvae048.
Pear psylla, Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae), occurs as 2 seasonal morphotypes. Summerforms occur on pear (Pyrus communis L.; Rosales: Rosaceae) where they are a significant pest. The larger and darker winterform morphotype develops in response to shortening daylengths and begins winter in reproductive diapause characterized by the absence of ovarian development. Diapausing winterforms often leave pear to overwinter on coniferous shelter plants and then return to pear in late winter and early spring to begin depositing the eggs that produce the first summerform generation. Cacopsylla pyricola adults are attracted to the color of foliage most of the year, but little is known about the role of plant volatiles in host finding and in seasonal dispersal between host and shelter plants by the psyllid. We used a Y-tube olfactometer and choice assays to investigate the response by C. pyricola adults to volatiles emitted by pear and an evergreen tree (cypress) often used as a shelter plant by wintering C. pyricola. Attraction to pear and cypress volatiles varied by season, tree phenology, and psyllid physiology. Cacopsylla pyricola were attracted to cypress volatiles and preferred to settle on cypress shoots during winter and early spring but then shifted to a marked preference for the pear developmental host in late spring and summer. Female C. pyricola exhibited stronger responses to pear volatiles than did males. Our study is the first to show that plant volatiles have a role in host finding by C. pyricola and provides a foundation for research on chemical ecology and management of C. pyricola.
梨木虱，栗臀叶蝉（ Foerster ）（半翅目：叶蝉科），有 2 种季节性形态型。夏季型出现在梨树上（ Pyrus communis L.；蔷薇目：蔷薇科），在那里它们是一种重要的害虫。较大和较暗的冬季型形态型是由于短日照而发育的，并以缺乏卵巢发育为特征进入生殖滞育期。滞育的冬季型经常离开梨树到针叶 shelter 植物上越冬，然后在冬末和早春返回梨树，开始产卵，这些卵产生第一代夏季型。栗臀叶蝉成虫一年中的大部分时间都被树叶的颜色所吸引，但对植物挥发物在宿主寻找和叶蝉在宿主和 shelter 植物之间季节性扩散中的作用知之甚少。我们使用 Y 型嗅觉仪和选择测定法来研究 C. pyricola 成虫对梨和常被用作冬季 C. pyricola shelter 植物的常绿树（柏树）释放的挥发物的反应。对梨和柏树叶挥发物的吸引力因季节、树木物候和叶蝉生理而异。Cacopsylla pyricola 在冬季和早春对柏树叶挥发物有吸引力，并倾向于在柏树上定居，但随后在春末和夏季转向对梨发育宿主的明显偏好。雌 C. pyricola 对梨挥发物的反应比雄 C. pyricola 更强。我们的研究首次表明，植物挥发物在 C. pyricola 的宿主寻找中起作用，并为 C. pyricola 的化学生态学和管理研究提供了基础。
