Department of Entomology and Nematology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
Exp Appl Acarol. 2013 Oct;61(2):183-93. doi: 10.1007/s10493-013-9680-z. Epub 2013 Feb 28.
Pyrethroid insecticides are generally regarded as acutely toxic to predatory phytoseiid mites; however, persistence of hull split spray pyrethroid residues on almond trees and their effects on phytoseiids have not been quantified over time. Hull split, the separation of the almond hull along the suture, exposes the new crop nuts to infestation by Amyelois transitella (Walker) larvae, and is the preferred timing for insecticides applied for their control. Galendromus occidentalis (Nesbitt) is the most important phytoseiid biocontrol agent for web-spinning spider mites in California (USA) almond orchards, and the impact of bifenthrin and λ-cyhalothrin pyrethroid residue on their survival, fertility, and fecundity was determined. The total effects of direct contact with esfenvalerate, permethrin, bifenthrin and λ-cyhalothrin were also evaluated for comparison. The total effects (E) of direct contact treatments of the four pyrethroids ranged from 77.8 % for esfenvalerate to 98.8 % for bifenthrin. Both bifenthrin and λ-cyhalothrin twig residue would be considered harmful (IOBC class 4) following field application at hull split timing. Bifenthrin twig residue would be considered slightly harmful (IOBC class 2) for up to 3.5 months and harmless (IOBC class 1) after 6 months. λ-cyhalothrin residue would be considered moderately harmful (IOBC class 3) for up to 3.5 months following application and harmless (IOBC class 1) after 6 months. Bifenthrin and λ-cyhalothrin twig residue on treated trees significantly reduced G. occidentalis female survival for up to 6 months post-treatment, however total effects (E) classify these residues as harmless (IOBC class 1) after 6 months. Harmful effects of direct and residual exposure following application have implications for the use of these pyrethroids in an integrated mite management program for perennial crops.
拟除虫菊酯杀虫剂通常被认为对捕食性叶螨具有急性毒性；然而，杏仁树上的裂壳喷雾拟除虫菊酯残留及其对叶螨的影响并没有随着时间的推移而被量化。裂壳，即杏仁壳沿着缝合线的分离，使新收获的坚果容易受到 Amyelois transitella (Walker)幼虫的侵害，这也是应用杀虫剂控制它们的首选时机。加利福尼亚州（美国）杏仁果园中，捕食性植绥螨的最重要的叶螨生物防治剂是西方西方盲走螨 Galendromus occidentalis (Nesbitt)，双丙环虫酯和 λ-氯氟氰菊酯拟除虫菊酯残留对其生存、生育力和繁殖力的影响已被确定。还评估了直接接触 esfenvalerate、氯菊酯、双丙环虫酯和 λ-氯氟氰菊酯的总效应，以作比较。直接接触处理这四种拟除虫菊酯的总效应（E）范围从 esfenvalerate 的 77.8%到 bifenthrin 的 98.8%。双丙环虫酯和 λ-氯氟氰菊酯的嫩枝残留物在裂壳时进行田间施药后，都将被认为是有害的（IOBC 类别 4）。双丙环虫酯的嫩枝残留物在 3.5 个月内将被认为是轻微有害的（IOBC 类别 2），6 个月后将被认为是无害的（IOBC 类别 1）。施药后 3.5 个月内，λ-氯氟氰菊酯的嫩枝残留物将被认为是中度有害的（IOBC 类别 3），6 个月后将被认为是无害的（IOBC 类别 1）。处理过的树上的双丙环虫酯和 λ-氯氟氰菊酯嫩枝残留物显著降低了西方西方盲走螨的雌性存活率长达 6 个月，但在 6 个月后，总效应（E）将这些残留物归类为无害（IOBC 类别 1）。施药后直接和残留接触的有害影响对这些拟除虫菊酯在多年生作物综合螨类管理计划中的应用具有重要意义。
