Hover flies (Diptera: Syrphidae) are an important group of insects that provide a multitude of key ecosystem services including pollination and biological control, yet many of their major life history traits are not understood. Some Palearctic hover fly species are known to migrate in response to changing seasonal conditions, yet this behavior is almost entirely unrecognized in Nearctic species. At least one species, Eupeodes americanus, is partially migratory during autumn while Allograpta obliqua may be non-migratory, but it is unknown where these insects originate and how far they may travel. We examined natal origins of two Nearctic hover fly species, A. obliqua and E. americanus, using stable hydrogen isotope (δ²H) measurements of metabolically inactive tissues (wings and legs) to derive a hover fly δ²H isoscape. While A. obliqua was mostly of local origin, several E. americanus were sourced from northern latitudes in the Midwestern United States and Canada, representing travel distance of up to 3000 km likely using seasonally favorable air currents. This phenomenon is expected to have major ecological and economic ramifications, especially in the realm of plant pollination ecology and biological control.

中文翻译：

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深入了解迁徙性近北极悬停蝇（双翅目：食蚜蝇科）的出生起源：来自稳定同位素 (δ2H) 分配分析的新证据

悬停蝇（双翅目：食蚜蝇科）是一类重要的昆虫，提供多种关键的生态系统服务，包括授粉和生物控制，但它们的许多主要生活史特征尚不清楚。已知一些古北区悬停蝇物种会根据不断变化的季节条件进行迁移，但这种行为在新北区物种中几乎完全未被识别。至少有一个物种，Eupeodes americanus，在秋季部分迁徙，而Allograpta obliqua可能是非迁徙的，但不知道这些昆虫起源于何处以及它们可能迁徙多远。我们使用稳定的氢同位素( δ ²H) 测量代谢不活跃的组织（翅膀和腿）以获得悬停飞行的 δ ² H 等值图。虽然A. obliqua主要起源于当地，但一些E. americanus来自美国中西部和加拿大的北纬地区，代表旅行距离可达 3000 公里，可能使用季节性有利的气流。预计这种现象将产生重大的生态和经济影响，特别是在植物授粉生态学和生物控制领域。