Patterns of sperm storage in twice-mated Queensland fruit flies

•Sperm storage by twice-mated female Queensland fruit fly was assessed.•Lines fixed for 3 SSR alleles were developed for sperm counting and genotyping.•Females stored fewer sperm from their second mate than from their first mate.•Number and asymmetry of sperm from first mates constrained storage of second mates.•Limits of spermathecal capacity affect sperm storage patterns.