Effects of insecticide and acaricide mixtures on Diaphorina citri control

Abstract Pesticide mixtures are commonly used to reduce production costs in agriculture. However, the consequences of such practice towards target organisms are still unknown in most cases. Therefore, this study aimed to evaluate the effects of combinations of insecticides and one worldwide used acaricide on the control of Diaphorina citri (Asian citrus psyllid). All insecticides alone (lambda-cyhalothrin+thiamethoxam, phosmet, and imidacloprid) and in combination with spirodiclofen were efficient in controlling D. citri (> 80%). No significant effects were found for combinations of lambda-cyhalothrin+thiamethoxam and phosmet insecticides with spirodiclofen. Conversely, imidacloprid caused an antagonistic effect on the control of D. citri when mixed with the acaricide. After all, spirodiclofen had no effect on the pH and electrical conductivity of insecticidal spray solutions. Spirodiclofen mixtures with lambda-cyhalothrin+thiamethoxam and phosmet had no effect on D. citri control, but combinations with imidacloprid interfered with it.摘要 农药混配是农业生产中普遍采用的降低生产成本的方式。然而，该施药方式对靶标生物的影响在绝大多数情况下仍未明确。为此，本研究旨在评估多种杀虫剂与一种全球广泛使用的杀螨剂（acaricide）复配后，对柑橘木虱（Diaphorina citri，Asian citrus psyllid）的防治效果。所有受试杀虫剂单用（氯氟氰菊酯+噻虫嗪（lambda-cyhalothrin+thiamethoxam）、亚胺硫磷（phosmet）、吡虫啉（imidacloprid））以及其与螺螨酯（spirodiclofen）复配的制剂，对柑橘木虱（D. citri）的防效均超过80%。其中，氯氟氰菊酯+噻虫嗪、亚胺硫磷分别与螺螨酯复配时，未对防治效果产生显著影响；与之相反，吡虫啉与该杀螨剂混配后，对柑橘木虱的防治产生了拮抗作用。此外，螺螨酯对杀虫剂喷雾液的pH值与电导率均无显著影响。氯氟氰菊酯+噻虫嗪、亚胺硫磷与螺螨酯的复配组合未对柑橘木虱的防治效果造成影响，但吡虫啉与螺螨酯的复配组合则对防治效果产生了干扰。