ABSTRACT

Megaselia halterata (Wood) (Diptera: Phoridae) is a major pest of cultivated white button mushrooms, Agaricus bisporus (J.E.Lange) Emil J. Imbach (Agaricales: Agaricaceae), in the United States. The incidence and severity of M. halterata have been increasing in recent years, possibly due to the removal of certain chemical pesticides from tolerance by the EPA. Farmers’ demand for alternative control measures resulted in a label extension of the fungal biopesticide BotaniGard^® ES, which contains viable spores of Beauveria bassiana (GHA strain), for use in mushroom crops. Here we describe laboratory bioassays to evaluate the efficacy of the label recommended dose of the abovementioned commercial biopesticide for control of immature and adult stages of M. halterata. According to our results, eggs and larvae of M. halterata were not susceptible to infection by B. bassiana whereas pupae displayed a partial susceptibility with mortality reaching up to 65%. Concerning adults of M. halterata exposure for 60 min to a paper surface sprayed with the registered label application rate of BotaniGard^® ES led to 100% mortality within a period of 16 days and a mean survival time of 8.13 days, which differed significantly from the control batch, but unlikely to result in meaningful control of phorid populations in the field. Further studies should be examined to increase efficacy of the formulated product against immature and adult stages of M. halterata.

摘要

Megaseliahalterata (Wood) (Diptera: Phoridae) 是美国栽培的白蘑菇双孢蘑菇(JELange) Emil J. Imbach (Agaricales: Agaricaceae) 的主要害虫。M.halterata的发病率和严重程度近年来一直在增加，这可能是由于 EPA 取消了某些化学农药的耐受性。农民对替代控制措施的需求导致真菌生物农药 BotaniGard ^® ES的标签扩展，其中包含白僵菌的活孢子（GHA 菌株），用于蘑菇作物。在这里，我们描述了实验室生物测定，以评估上述商业生物杀虫剂的标签推荐剂量对控制未成熟和成虫阶段的M.halterata 的功效。根据我们的研究结果，M.halterata 的卵和幼虫不易被B. bassiana感染，而蛹表现出部分易感性，死亡率高达 65%。关于M.halterata 成虫暴露于喷有 BotaniGard ^®注册标签应用率的纸表面 60 分钟ES 在 16 天的时间内导致 100% 的死亡率和 8.13 天的平均存活时间，这与对照批次有显着差异，但不太可能对田间的 phorid 种群进行有意义的控制。应检查进一步的研究，以提高配制产品对M.halterata未成熟和成虫阶段的功效。