Effects of Starvation on Death-Feigning in Adults of Cylas formicarius (Coleoptera: Brentidae)

Effects of starvation on death-feigning behavior, or thanatosis, were observed in adults of the sweetpotato weevil, Cylas formicarius (F.). A significantly lower proportion of death-feigned adults was observed in starved weevils compared with unstarved controls in both sexes. However, females needed a longer starvation period than males to show the decreased proportion of death-feigning. This contrast between males and females was caused by a differential tolerance of the sexes for starvation, because males died earlier than females without food. Starved male weevils had a shorter duration to recover from the death-feigning. There may be situations where C. formicarius gives priority to assuring food consumption compared with escaping from predators.