Studies on Resistance and Mechanism of Aphis gossypii in Main Planting Vegetables Areas of Shandong Province

The Aphis gossypii were collected from four main areas of planting vegetables of Shandong province. That of resistance to fenvalerate, imidacloprid, omethoate, and methomyl were tested by topical application of capillary tube. The results showed that the resistance ratios of LC-Population (the Aphis gossypii collected from Liaocheng area) and SG-Population (collected from Shouguang area) were 121 710.1 and 27 459.3 folds to fenvalerate.That of resistance ratios were 9.6,29.4,7.9 folds and 4.1, 18.1, 29 folds to imidacloprid, omethoate and methomyl. The resistance ratios of CS- Population and TA Population (colletced from CangShan and Taian areas) to the four kind of insecticides were lower than that of LC Population and SG Population. The results of enzymic activities and in vivo treatment with inhibitor showed that the resistance of LC-Population was mainly associated with the increasing activities of mixed function oxidases, carboxylesterase, acetylcholinesterase and glutathione transferase.