The negative cross-resistance and biological characteristics of pyridaben to imidacloprid-resistant population of Aphis gossypii Glover (Hemiptera: Aphididae)
Abstract:In order to clarify the control effects of pyridaben on imidacloprid-resistant population of Aphis gossypii, we used the wingless adult aphids of the imidacloprid-resistant population (RF27), the Xiajin population (XJ) and the susceptible population (SS) to assay negative cross-resistance and biological characteristics of pyridaben to imidacloprid-resistant population of Aphis gossypii by using the dipping method, microspot method, biochemical method and systematic observation method, respectively. The results showed that the LD50 of pyridaben to RF27, XJ and SS was 1.065×10-5μg/aphid, 6.616×10-5μg/aphid and 4.862×10-5μg/aphid, respectively. RF27 exhibited obviously negative cross-resistance to pyridaben and pymetrozine, and the RF27 exhibited cross-resistance to other pesticides (acetamiprid, nitenpyram, etc). The enhancement of activities of CarE, GST and AChE would be the main metabolic mechanism of the occurrence of resistance. Pyridaben had obvious inhibition on the AChE and GST activities of Aphis gossypii. The RF27 treated by pyridaben showed developmental disadvantages, the relative fitness was 0.67.