Raw data and code for the paper: Do Nearctic hover flies (Diptera: Syrphidae) engage in long-distance migration? An assessment of evidence and mechanisms

This dataset is for the publication "Do Nearctic hover flies (Diptera: Syrphidae) engage in long-distance migration? An assessment of evidence and mechanisms." It consists of 11 Excel spreadsheets and 4 R scripts which correspond to the analyses which were conducted. Paper abstract: Long-distance insect migration is poorly understood despite its tremendous ecological and economic importance. As a group, Nearctic hover flies (Diptera: Syrphidae: Syrphinae), which are crucial pollinators as adults and biological control agents as larvae, are almost entirely unrecognized as migratory despite examples of highly migratory behavior among several Palearctic species. Here, we examined evidence and mechanisms of migration for four hover fly species (Allograpta obliqua, Eupeodes americanus, Syrphus rectus, and Syrphus ribesii) common throughout eastern North America using stable hydrogen isotope (δ2H) measurements of chitinous tissue, morphological assessments, abundance estimations, and cold-tolerance assays. While further studies are needed, non-local isotopic values obtained from hover fly specimens collected in central Illinois support the existence of long-distance fall migratory behavior in Eu. americanus, and to a lesser extent S. ribesii and S. rectus. Elevated abundance of Eu. americanus during the expected autumn migratory period further supports the existence of such behavior. Moreover, high phenotypic plasticity of morphology associated with dispersal coupled with significant differences between local and non-local specimens suggest that Eu. americanus exhibits a unique suite of morphological traits that decrease costs associated with long-distance flight. Finally, compared to the ostensibly non-migratory A. obliqua, Eu. americanus was less cold tolerant, a factor that may be associated with migratory behavior. Collectively, our findings imply that fall migration occurs in Nearctic hover flies, but we consider methodological limitations of our study in addition to potential ecological and economic consequences of these novel findings.

本数据集旨在为发表于《北美洲悬停蝇（双翅目：花蝇科）是否参与长途迁徙？证据与机制评估》一文的科研工作提供支持。数据集包含11个Excel电子表格和4个R语言脚本，对应于所进行的分析研究。论文摘要：尽管长途昆虫迁徙在生态和经济上具有极其重要的意义，但其机制仍鲜为人知。作为一群至关重要的授粉者（成虫阶段）和生物防治剂（幼虫阶段）的北美洲悬停蝇（双翅目：花蝇科：花蝇亚科），尽管在多个古北区的物种中发现了高度迁徙的行为例子，但它们几乎未被认定为迁徙生物。在本研究中，我们通过稳定氢同位素（δ2H）测量壳质组织、形态学评估、丰度估计和耐寒性试验，对东北美地区常见的四种悬停蝇（Allograpta obliqua、Eupeodes americanus、Syrphus rectus和Syrphus ribesii）的迁徙证据和机制进行了考察。尽管需要进一步研究，但来自伊利诺伊州中部的悬停蝇标本的非本地同位素值支持了Eu. americanus存在长途秋季迁徙行为的可能性，在S. ribesii和S. rectus中也有一定程度的存在。在预期的秋季迁徙期间，Eu. americanus的丰度增加进一步支持了这种行为的存在。此外，与散布相关的形态学表型可塑性的提高以及本地与非本地标本之间的显著差异表明，Eu. americanus展现出一系列独特的形态学特征，这些特征降低了长途飞行的成本。最后，与看似非迁徙的A. obliqua相比，Eu. americanus的耐寒性较低，这可能与迁徙行为有关。总体而言，我们的研究结果表明，在北美洲悬停蝇中确实存在秋季迁徙，但我们同时考虑了研究方法上的局限性以及这些新颖发现可能带来的生态和经济影响。