Effects of the Insect Growth Regulator Dimilin on Larval Development of Hemigrapsus sanguineus (Crustacea, Brachyura) Reared in the Laboratory

무늬발게 幼生에 對한 Dimilin 의 致死 影響

The effects of insect growth regulator Dimilin which interfere with the synthesis of chitin in the cuticle of insect larvae were investigated at various concentrations using the crab larvae of Hemigrapsus sanguineus. The larvae were cultured at control, 0.5, 1, 5 and 10 $\mu g$ Dimilin solutions and three replicate experiments were carried out to give correct analysis. Significant differences in percent mortality have occurred between control and 10$\mu g$ when the larvae were exposed to Dimilin whereas no differences were found between 5 and 10$\mu g$ Dimilin concentrations. If lethal concentration is defined as concentration at which less than 10 percent of crab larvae reach to the last zoeal stage from hatching it can be concluded that insect growth regulator Dimilin is lethal to the larvae of Hemigrapsus sanguineus at 5 and 10$\mu g$ Dimilin.