The western flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) causes bronzing to strawberry fruit. Management of insecticide-resistant strains relies on the integration of predators with carefully timed use of the few insecticides available. Effective management requires better understanding of economic injury levels (EILs) and the factors that affect them. The densities of F. occidentalis and the predatory mite Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) were manipulated in field experiments. All stages of flower and fruit were susceptible to thrips damage, but larvae caused nearly twice as much damage as adults per individual. The EIL was about four adult thrips per flower in the absence of predators, but increased to over eight at densities of N. cucumeris typical of good establishment in crops. The EIL could be increased by about 0.7 adult thrips per flower for every N. cucumeris per flower. The results were supported by measurements of EILs in commercial crops.

中文翻译：

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捕食性螨将草莓中富兰克氏菌的经济伤害水平提高了一倍。

西方花蓟马（Frankliniella occidentalis（Pergande）（Thysanoptera：Thripidae））使草莓果实烫金。抗杀虫剂菌株的管理依赖于捕食者的整合，并谨慎地定时使用几种可用的杀虫剂。有效的管理要求更好地了解经济损害水平（EIL）及其影响因素。西花蓟马和捕食性螨黄瓜新孢子虫（Neoseiulus cucumeris）的密度（Oudemans）（Acari：Phytoseiidae）在野外实验中被操纵。花和果实的所有阶段都容易受到蓟马的伤害，但是幼虫造成的伤害几乎是成年人的两倍。在没有捕食者的情况下，每朵花的EIL大约为4个成虫蓟马，但在典型的农作物中具有良好结实的黄瓜N.密度下，EIL增加到8个以上。每朵黄瓜枯草芽孢杆菌每株花朵的EIL可以增加约0.7个成虫蓟马。该结果得到商业作物中EIL的测量的支持。