Ancient hastisetae of Cretaceous carrion beetles (Coleoptera: Dermestidae) in Myanmar amber.

Hastisetae are extremely elaborate and intricate insect setae that occur solely on dermestid larvae (Coleoptera: Dermestidae). The present work characterizes hastisetae found in mid-Cretaceous amber from Myanmar and compares them to hastisetae found on extant dermestid larvae. The presence of hastisetae in Myanmar amber shows that lineages of dermestid beetles had already developed hastisetae by the mid-Cretaceous and their presence allows us to follow the evolutionary development of this particular arthropod structure over the past 100 million years. Hastisetae attached to a parasitic wasp in the same piece of amber indicates that ancient dermestid beetles used their hastisetae for defense, similar to their function today.