Abstract: The effects of six IGRs in LC_40-50 concentration on development and adult fecundity of onion maggot, Delia antique (Meigen) (Diptera: Anthomyiidae) were observed by treating the 1st and 3rd larvae of onion maggot with phoxim as a control. Adult fecundity was also investigated through continuous feeding the adults on milk solution with different IGRs. The results showed that, except tebufenozide, the other 5 IGRs had obviously adverse effects on larval development periods, pupation rate, pre-oviposition periods, adult longevity and eggs laid per female. Both larval development period and pre-oviposition period were prolonged by about 3 days, pupation rate was reduced by 26.7%-30.0%, adult longevity was decreased by 22.3-24.3 days and eggs laid per female was reduced by 35.5％-49.9％ when the 1st instars were treated with cyomazine and hexaflumuron. Whereas, when the 3rd instars were treated with these two IGRs, deformed pupae without resulting in larval death was observed, eggs laid per female was reduced by 45.7%-57.8％ and adult longevity was shortened by 18.0-20.67 days. Feeding the adults with milk solution with different IGRs in 1∶2000 (IGR∶milk) prolonged pre-oviposition period, decreased eggs laid per female and egg hatchability, remarkably increased mortality of 1st instar larvae which was as high as more than 95%. The results indicated that, taking advantage of the adult trait of nutrient supplement, cyromazine and hexaflumuron could be added into milk or sugar solution to lure the adult to reduce its fecundity effectively, which could make the environment-friendly management of onion maggot come true.

Key words: Delia antique, insect growth regulator, growth and development, fecundity