First Evidence of Cannibalism and Its Minimal Adaptive Value in <i>Earias insulana</i> (Boisduval) Larvae

ABSTRACT Cannibalism, though common in insects, varies in its adaptive value. This study provides the first evidence of cannibalism in Earias insulana (Boisduval) (Lepidoptera: Nolidae), a significant pest of okra and other crops. In laboratory experiments, over one‐third of group‐reared larvae were consumed by conspecifics, while non‐cannibalistic mortality rates were similar between group‐ and individually reared larvae. As a result, cannibalism reduced overall survival but did not affect larval or pupal development time, pupal weight, female fecundity, egg hatchability, or adult longevity. Cannibalism rate was higher under conditions of higher larval density. In choice tests, the larvae showed a preference for a low‐quality diet supplemented with dried conspecific larvae powder over an unsupplemented low‐quality diet, suggesting chemical cues influence feeding choices. In field‐collected okra pods, 34.5% were infested with E. insulana , mostly with one larva per pod, indicating behavioral or spatial strategies that limit direct encounters and cannibalism. These findings suggest that cannibalism in E. insulana is frequent but offers minimal, if any, direct fitness benefits. Its potential indirect benefit may lie in regulating local population density, possibly reducing predator attraction. While crowding and poor‐quality food appeared to be the key drivers of cannibalism, the behavior was also observed even at low densities and with adequate food, suggesting that other factors are also involved.