Abstract: In Xinjiang cotton-growing region, the natural enemies thriving on the weeds within non-crop habitats in early spring are the main sources of natural enemies immigrating into cotton fields, and are the key for natural enemy conservation outside cotton fields. In practice, herbicides are widely used to prevent malignant weeds on the ridges, which can potentially exert adverse effect on non-target natural enemies. In this study, we found no significant effects of eight herbicides on the egg hatchability, pupal emergence rate and adult survival rate of Hippodamia variegata (Goeze). However, the survival rate of the 3^rd instar larvae treated with Quizalofop-p-ethyl, Tribenuron-methyl, Fenoxaprop-p-ethyl was significantly lower than that of the control group while there were no significant differences in larval survival rates in the larvae treated with Haloxyfop-P-methyl, Floazifop-p-butyl, Clethodim, Fluroxypyr, and Oxyfluorfen in comparison with the control group. Eggs treated by Haloxyfop-P- methyl and Oxyfluorfen showed no significant differences in immature developmental duration, survival rates and pupal weight, with exception of significantly reduced pupation rate in Haloxyfop-P-methyl treatment. No significant effect was observed on the growth and development of 3^rd instar larvae treated with Haloxyfop-P-methyl and Oxyfluorfen. The study show that the herbicides commonly used in Xinjiang farmland are relatively safe for H. variegate, with no obvious toxic and negative effects.

Key words: Hippodamia variegata, herbicides, survival, growth and development, safety evaluation