Everglades Research and Education Center, University of Florida Institute of Food and Agricultural Sciences, 3200 East Palm Beach Road, Belle Glade, FL 33430, USA.
West Florida Research and Education Center, University of Florida Institute of Food and Agricultural Sciences, 4253 Experiment Drive, Highway 182, Jay, FL 32565, USA.
J Econ Entomol. 2022 Oct 12;115(5):1685-1692. doi: 10.1093/jee/toac125.
Picture-winged flies (Diptera: Ulidiidae) are the most damaging insect pests of sweet corn (Zea mays L.) produced in Florida for the fresh market. Management of these pests, referred to as corn silk flies, relies on frequent pyrethroid applications targeting adults. In response to the need for an insecticide resistance management (IRM) program for corn silk flies in this highly intensive crop system, glass vial bioassays were conducted to determine the susceptibility of 12 corn silk fly populations to the pyrethroid beta-cyfluthrin. Two Euxesta eluta Loew and nine Euxesta stigmatias Loew populations were obtained by collecting infested ears in commercial and experimental fields in 2020 and 2021. One E. eluta laboratory colony was used as a susceptible reference population. The E. eluta reference colony was the most susceptible population, with an LC50 value of 0.01 µg/vial. The E. stigmatias field populations were generally less susceptible to beta-cyfluthrin than the E. eluta field populations, with the highest LC50 values attaining 3.51 µg/vial and 0.19 µg/vial, respectively. In addition, the five E. stigmatias populations from commercial sweet corn fields were as much as 17.6 times less susceptible than the four E. stigmatias populations from nontreated fields. Results suggest that E. stigmatias is less susceptible to pyrethroids than E. eluta. Results also suggest that corn silk flies in commercial sweet corn fields are selected for reduced pyrethroid susceptibility throughout the growing season. This study successfully used the glass vial bioassay method for corn silk flies, providing a new tool to initiate an IRM program.
图片翅蝇（双翅目：Ulidiidae）是佛罗里达州为新鲜市场生产的甜玉米（Zea mays L.）最具破坏性的虫害之一。这些被称为玉米丝蝇的害虫的管理依赖于针对成虫的频繁拟除虫菊酯应用。为了应对在这种高度集约化的作物系统中对玉米丝蝇进行杀虫剂抗性管理（IRM）计划的需要，进行了玻璃管生物测定，以确定 12 种玉米丝蝇种群对拟除虫菊酯 beta-氯氟氰菊酯的敏感性。2020 年和 2021 年，通过在商业和实验田收集受感染的耳朵，获得了 2 个 Euxesta eluta Loew 和 9 个 Euxesta stigmatias Loew 种群。一个 E. eluta 实验室品系被用作敏感参考种群。E. eluta 参考种群是最敏感的种群，LC50 值为 0.01 µg/管。E. stigmatias 田间种群对 beta-氯氟氰菊酯的敏感性通常低于 E. eluta 田间种群，最高 LC50 值分别达到 3.51 µg/管和 0.19 µg/管。此外，来自商业甜玉米田的 5 个 E. stigmatias 种群比来自未处理田地的 4 个 E. stigmatias 种群的敏感性低 17.6 倍。结果表明，E. stigmatias 对拟除虫菊酯的敏感性低于 E. eluta。结果还表明，商业甜玉米田中的玉米丝蝇在整个生长季节都因对拟除虫菊酯的敏感性降低而受到选择。本研究成功地使用了玉米丝蝇的玻璃管生物测定方法，为启动 IRM 计划提供了一种新工具。
