In insects, death‐feigning is an effective defence strategy. Eucryptorrhynchus brandti, a major borer pest in China, has a weak flight ability and exhibits obvious death‐feigning behaviour when disturbed. Despite a large number of studies of its biological and ecological properties as well as control methods, the death‐feigning behaviour has not been specifically described. In laboratory conditions, we recorded the survival rate under starvation and feeding conditions and evaluated the effect of starvation on the duration and occurrence of death‐feigning. In a continuous experiment, we examined variation in the death‐feigning duration every day over 7 day. Then, we evaluated the effects of starvation for 3, 6 and 9 day in a non‐continuous experiment and further observed variation in the death‐feigning intensity. We found that starvation significantly affected the survival rate. Survival time was significantly longer in the starvation group than in the feeding group, and females had longer survival times than males (female: 14 day, male: 8 day). In the continuous experiment, starved E. brandti had the longest duration of death‐feigning at 2 day, followed by a significant decrease. In the non‐continuous experiment, the duration and proportion of death‐feigning decreased significantly as the duration of starvation increased and were significantly lower than feeding. These observations suggest that starvation is a non‐negligible factor in the death‐feigning behaviour of E. brandti adults, facilitating the interpretation of future ecological and behavioural data of thanatosis.
For example, specifi c sounds (alarm calls) can increase the duration of TI in Gallus gallus (Pochron & Thompson, 2019) and in two species of Callosobruchus, C. chinensis and C. maculatus (Miyatake et al., 2008a), high incidence of TI is associated with low temperatures (15°C and 20°C) and its duration is correlated negatively with increase in ambient temperature when TI is induced by touching. Thus, the variation in TI in different species associated with environmental factors is worthy of further study.Recent studies indicate that TI behaviour also depends on the sex and weight of an insect (Li et al., 2019; Konishi et al., 2020). For example, TI in C. chinensis stimulated by touching, is longer in heavy females than males (Hozumi & Miyatake, 2005
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.