Do male and female beetles (Tenebrio molitor) respond differently to rat feces containing eggs from the tapeworm, Hymenolepis diminuta?

Abstract

Males and females often differ in their susceptibility and exposure to infection. Thus, they may also differ in their ability to avoid infection. The beetle, Tenebrio molitor, risks infection with cysticercoids when ingesting rat feces containing eggs of the tapeworm, Hymenolepis diminuta. Previous studies demonstrated that beetles sometimes prefer infective feces suggesting that the tapeworm influences the foraging behavior of beetles. After recording beetle movement in an arena containing infective and uninfective feces for one hour, sex main effects were not significant, but the effect of sex asked in trials was significant for males. Specifically, more male beetles occurred on the uninfective bait than on the infective bait. This observation suggests that male beetles avoid infective feces, which decreases their probability of infection with H. diminuta. If the cost of infection is higher in males, then selection to avoid infective feces may act more strongly on males.