Homozygous mutant embryos hatch normally and proceed through first and second larval instars without any apparent defect. Developmental retardation was apparent during the middle of the third larval instar. 10-30% of larvae become increasingly sluggish and flaccid and do not reach pupariation. The majority of larvae pupate but cease to develop, less than 10% reach pharate adult stage. No adults eclose. No cuticular abnormalities are apparent these adults.