Fernández-Grandon G Mandela, Harte Steven J, Ewany Jaspher, Bray Daniel, Stevenson Philip C
Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK.
Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, UK.
Plants (Basel). 2020 Feb 1;9(2):173. doi: 10.3390/plants9020173.
Sustainable agricultural intensification employs alternatives to synthetic insecticides for pest management, but these are not always a direct replacement. Botanical insecticides, for example, have rapid knockdown but are highly labile and while biological pesticides are more persistent, they are slow acting. To mitigate these shortcomings, we combined the entomopathogenic fungus (EPF) with pyrethrum and evaluated their efficacy against the bean aphid, . To ascertain higher trophic effects, we presented these treatments to the parasitoid, on an aphid infested plant in a Y-tube olfactometer and measured their preferences. Aphid mortality was significantly higher than controls when exposed to EPF or pyrethrum but was greater still when exposed to a combination of both treatments, indicating an additive effect. This highlights the potential for applications of pyrethrum at lower doses, or the use of less refined products with lower production costs to achieve control. While parasitoids were deterred by aphid infested plants treated with EPF, no preference was observed with the combination pesticide, which provides insight into the importance that both application technique and timing may play in the success of this new technology. These results indicate the potential for biorational pesticides that combine botanicals with EPF.
可持续农业集约化采用合成杀虫剂替代品进行害虫管理，但这些替代品并不总是能直接替代。例如，植物源杀虫剂击倒速度快，但极不稳定，而生物农药虽然更持久，但作用缓慢。为了弥补这些缺点，我们将昆虫病原真菌（EPF）与除虫菊相结合，并评估了它们对豆蚜的防治效果。为了确定更高营养级的影响，我们在Y型嗅觉仪中，将这些处理方法应用于蚜虫侵染的植物上的寄生蜂，并测量它们的偏好。当暴露于EPF或除虫菊时，蚜虫死亡率显著高于对照组，但当同时暴露于两种处理时，死亡率更高，表明存在相加效应。这突出了以较低剂量使用除虫菊或使用生产成本较低的粗加工产品来实现防治的潜力。虽然寄生蜂会被用EPF处理过的蚜虫侵染植物所排斥，但对于组合农药没有观察到偏好，这为应用技术和时机在这项新技术成功中可能发挥的重要性提供了见解。这些结果表明了将植物源物质与EPF相结合的生物合理农药的潜力。
