Chemical control remains the main method of controlling the cotton aphid (Aphis gossypii Glover). Millions of dollars have been lost due to plant damage which resulted in reduced quality and yield of cotton. Nevertheless, A. gossypii can rapidly develop resistance to different groups of insecticides such as organophosphates, carbamates and pyrethroids. The potential of Huwa-San TR50 in controlling A. gossypii is yet to be tested. Huwa-San TR50 is a formula of hydrogen peroxide which has been stabilized by the addition of a small quantity of silver and has extensively used as a disinfectant. In this study, it was found to be very potent in killing A. gossypii and produced 93.5, 96.5, 97 and 95.5% mortality at 1000, 2000, 3000 and 4000 ppm, respectively, after 48 h of exposure. Furthermore, there was no significant difference between four Huwa-San TR50 concentrations after 48 h of exposure, on the mortality of A. gossypii. Huwa-San TR50 of up to 4000 ppm had no observable effects on the mortality and behavior of adult honeybee workers (Apis mellifera lamarckii) as compared with the control. Also, Huwa-San TR50 concentration of up to 3000 ppm had no observable effect on seven-spot ladybird beetles (Coccinella septempunctata) whereas a concentration of 4000 ppm produced 100% mortality after 24 h of exposure. Huwa-San TR50 concentrations of up to 2000 ppm failed to produce any symptoms on cucumber leaves. The differential effects of Huwa-San TR50 on aphids and beneficial insects, suggest the need for further investigation to understand the effects of Huwa-San TR50 on other host plants of aphids and aphid species.
Identification of Aphis gossypii Glover (Hemiptera: Aphididae) Biotypes from Different Host Plants in North China
