›› 2009, Vol. 52 ›› Issue (2): 175-182.

• RESEARCH PAPERS • Previous Articles     Next Articles

Cross-resistance of the imidacloprid-resistant population of Aphis gossypii Glover (Homoptera: Aphididae) to pymetrozine and other three pesticides and the effects of pesticide application on its biological characteristics


  • Online:2009-03-18 Published:2009-02-20

Abstract: In order to clarify the control effects of pymetrozine on imidacloprid-resistant population of Aphis gossypii, and bring forward proposals on its management strategies,we used the wingless adult aphids of the imidacloprid-resistant population (RF27), the Xiajin population (XJ) and the susceptible population (SS) to assay the cross-resistance of the RF27 to pymetrozine and other pesticides and the effects of pesticide application on its biological characteristics by using the dipping method, microspot method, biochemical method and systematic observation method, respectively. The results showed that the LD50 of pymetrozine to RF27 was 1.213×10-5 μg/aphid, to XJ was 8.506×10-5 μg/aphid, and to SS was 5.140×10-5 μg/aphid, so RF27 exhibited obviously negative cross-resistance to pymetrozine. The resistance ratio of RF27 to acetamiprid, nitenpyram and buprofezin was 2.35, 2.98 and 1.71, respectively. Activities of carboxylesterases (CarE) and gluathione-S-transferases (GSTs) in RF27 were significantly higher than those in SS, suggesting that the enhancement of activities of CarE and GSTs would be the main metabolic mechanism of the occurrence of resistance. Pymetrozine had an obvious inhibition on the CarE and GSTs activities in RF27, XJ and SS. RF27 treated by pymetrozine showed developmental disadvantages, including the lower nymphal survival rate (only 64.60%), the lower net reproductive rate (10.39) , the longer mean generation time (10.87 d), the lower intrinsic rate of natural increase and the finite rate of increase (0.21 and 1.23 respectively), and the lower relative fitness (only 0.70). These results suggest that pymetrozine has high application value in controlling A. gossypii.

Key words: Aphis gossypii, imidacloprid, pymetrozine, cross-resistance, biological characteristics