For arthropod escape artists, survival depends on size

Abstract

Beetles’ explosive exit strategy Shinji Sugiura caught his crawly contenders at night. Long after tourists left the forest trails in central Japan, the Kobe University biologist collected bombardier beetles, along with their natural predators, the sticky-tongued toads, to see which bugs were best suited for survival. Bombardier beetles are a resilient bunch. Armed with a chemical weapon that helps them escape their attackers even from within the toads’ tummies, the beetles blast a hot spray of water vapor and irritating compounds called quinones that makes the toads vomit them out. The beetles’ defense system, while explosive, isn’t surefire. Sugiura and colleagues set out to find out why through a series of experiments in which toads and beetles were placed inside small enclosures where they duked it out one-on-one (Biol. Lett. 2018, DOI: 10.1098/rsbl.2017.0647). First, the team tried placing toads with beetles that were unable to release chemicals: The scientists got