Instituto de Ciencias Agrarias (ICA). Consejo Superior de Investigaciones Científicas (CSIC). Calle Serrano 115dpdo, Madrid, Spain.
Departamento de Producción Agraria, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas (ETSIAAB), Universidad Politécnica de Madrid (UPM), Madrid, Spain.
Pest Manag Sci. 2022 Nov;78(11):4841-4849. doi: 10.1002/ps.7105. Epub 2022 Aug 17.
Insecticides are essential, though controversial tools in modern pest management. Insecticides can slow the spread of key vector-borne plant pathogens, but often lead to inconsistent results given that insecticide use is generally focused on acute toxicity under no-choice conditions. Here, we analysed the lethal (survival) and sublethal (feeding behaviour) effects of six commercial products (acetamiprid, deltamethrin, spinosad, sulfoxaflor, pyrethrin and kaolin) on Philaenus spumarius, vector of the bacterium Xylella fastidiosa. Furthermore, we assessed the impact of insecticides displaying different degrees of acute toxicity against spittlebugs (highest to lowest: acetamiprid, pyrethrin and kaolin) on the transmission of X. fastidiosa by P. spumarius under both free-choice and no-choice conditions.
Deltamethrin, acetamiprid and to a limited extent pyrethrin significantly altered the feeding behaviour of P. spumarius. Deltamethrin and acetamiprid were highly toxic against P. spumarius, but the mortality induced by exposure to pyrethrin was limited overall. By contrast, spinosad, sulfoxaflor and kaolin did not significantly impact P. spumarius feeding behaviour or survival. Under no-choice conditions, both pyrethrin and acetamiprid reduced the X. fastidiosa inoculation rate compared with kaolin and the control. On the other hand, pyrethrin reduced transmission, but acetamiprid failed to significantly affect bacterial inoculation under free-choice conditions.
Pyrethrin was the only compound able to reduce X. fastidiosa transmission under both free-choice and no-choice conditions. Xylella fastidiosa management strategy based exclusively on the evaluation of insecticide acute toxicity under no-choice conditions would most likely fail to prevent, or slow, bacterial spread. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
杀虫剂是现代病虫害管理中必不可少但有争议的工具。杀虫剂可以减缓关键媒介传播的植物病原体的传播，但由于杀虫剂的使用通常集中在无选择条件下的急性毒性上，因此往往导致结果不一致。在这里，我们分析了六种商业产品（乙酰甲胺磷、溴氰菊酯、多杀菌素、螺虫乙酯、除虫菊素和高岭土）对传病介体沫蝉（Philaenus spumarius）的致死（存活）和亚致死（取食行为）效应。此外，我们评估了显示不同程度急性毒性的杀虫剂（从高到低：乙酰甲胺磷、除虫菊素和高岭土）对沫蝉在自由选择和非选择条件下传播黄单胞菌的影响。
溴氰菊酯、乙酰甲胺磷和在一定程度上除虫菊素显著改变了沫蝉的取食行为。溴氰菊酯和乙酰甲胺磷对沫蝉具有高毒性，但除虫菊素引起的死亡率总体上有限。相比之下，多杀菌素、螺虫乙酯和高岭土对沫蝉的取食行为或存活没有显著影响。在非选择条件下，除虫菊素和乙酰甲胺磷都降低了黄单胞菌的接种率，而与高岭土和对照相比。另一方面，除虫菊素降低了传病率，但在自由选择条件下，乙酰甲胺磷未能显著影响细菌接种。
除虫菊素是唯一一种能够在自由选择和非选择条件下降低黄单胞菌传播的化合物。基于无选择条件下杀虫剂急性毒性评估的黄单胞菌管理策略很可能无法阻止或减缓细菌的传播。
