The test was carried out to metamorphosis of the surviving larvae to postiarvae with four 6‐h pulse doses. The LC50's ranged from 0.94 μg/L after the first pulse exposure to 0.29 μg/L at the end of the study.
Among the five chlorpyrifos concentrations and the control, there were no significant differences in larval molting and metamorphosis and growth (postlarval dry weight).