Abstract Insecticidal neonicotinoid seed treatments are a common agricultural insect pest management strategy; however, effects on nontarget pests and omnivorous arthropods are understudied. We used a series of experiments to evaluate impacts of the neonicotinoid seed treatment thiamethoxam on densities of herbivorous twospotted spider mites (Tetranychus urticae Koch [Acari:Tetranychidae]) and feeding behavior of western flower thrips (Frankliniella occidentalis Pergande [Thysanoptera: Thripidae]), an omnivore that feeds on spider mite eggs but is also a significant plant pest. Spider mite densities were higher on neonicotinoid-treated soybeans, but only when mites were not spatially confined.We then examined how availability of thiamethoxam-treated food items (i.e., eggs from spider mites reared on treated soybeans, soybean leaf discs, or a combination of the two), and previous exposure to thiamethoxam-treated soybean impacted thrips feeding. Regardless of the presence of leaf tissue, thrips consumed fewer spider mite eggs laid by females reared on treated soybeans, suggesting spider mite eggs can serve as poisoned prey. Overall, thrips consumed less treated soybean leaf tissue, and thrips on treated leaf discs had a lower percentage of herbivorous feeding events and consumed more nontreated spider mite eggs, indicating a dietary shift from herbivory to predation. The neonicotinoid status of spider mite eggs and prior exposure of thrips also caused shifts in the number and size of leaf scars, likely as a result of altered foraging behavior and/or movement. Shifts between herbivory and predation have implications for thrips damage, virus transmission, and pest management, especially in systems with mixtures of nontreated and neonicotinoid-treated plants.

中文翻译：

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新烟碱类种子处理对大豆非目标草食动物（双斑蜘蛛）和共生杂食动物（西花蓟马）饮食转换的影响


摘要 新烟碱类杀虫剂种子处理是一种常见的农业害虫防治策略。然而，对非目标害虫和杂食性节肢动物的影响尚未得到充分研究。我们使用了一系列实验来评估新烟碱类种子处理剂噻虫嗪对草食性双斑叶螨（二斑叶螨 [蜱螨科：叶螨科]）密度和西花蓟马（西花蓟马 [缨翅目：蓟马科]）摄食行为的影响，一种杂食动物，以蜘蛛螨卵为食，但也是一种重要的植物害虫。经过新烟碱类杀虫剂处理的大豆上的叶螨密度较高，但前提是螨虫不受空间限制。然后，我们研究了经过噻虫嗪处理的食品（即，在经过处理的大豆、大豆叶盘或组合上饲养的叶螨卵）的可用性。两者中的一个），并且之前接触过噻虫嗪处理的大豆影响了蓟马的摄食。无论是否存在叶组织，蓟马消耗的雌性叶螨卵在经过处理的大豆上饲养的数量较少，这表明叶螨卵可以作为有毒的猎物。总体而言，蓟马消耗的处理过的大豆叶组织较少，处理过的叶盘上的蓟马食草性取食事件的百分比较低，并且消耗了更多未经处理的蜘蛛螨卵，表明饮食从草食性转向捕食性。红蜘蛛卵的新烟碱状态和之前接触蓟马的情况也会导致叶疤数量和大小的变化，这可能是由于觅食行为和/或运动的改变造成的。食草性和捕食性之间的转变对蓟马损害、病毒传播和害虫管理具有影响，特别是在未经处理和新烟碱类处理植物混合的系统中。