Sex differences in bedbug nymphs,Cimex lectularius

Bedbugs, Cimex lectularius, have re-gained their status as economically important insects in many parts of the world and, consequently, re-attracted research into their biology. Standardizing age, feeding and mating status of experimental animals requires easy and reliable identification of the nymphal sex. Here, we show the angle of the pointedness of the abdomen to be a reliable sex marker in nymphal stage 5, as well as the shape of the 9th sternite, allowing rapid nymph sorting by sex. The sexual dimorphism was driven by males, not females, departing from the larval growth trajectory.