Insects that embed themselves in ant colonies have existed for nearly as long as their hosts, and some have evolved rapidly, probably in response to ant diversification.

Credit: Joseph Parker and David A. Grimaldi

Joseph Parker at Columbia University and David Grimaldi from the American Museum of Natural History, both in New York, conclude that a 52-million-year-old beetle found entombed in amber (pictured) is the earliest known example of a myrmecophile — species that depend on ants for their survival. The newly identified species, Protoclaviger trichodens, is an extinct ancestor of contemporary rove beetles and has features such as hairs to deliver tasty secretions to worker ants. It existed just as ant populations were starting to rise in tropical rainforests.

In another myrmecophile study, Wendy Moore and James Robertson at the University of Arizona in Tucson used DNA sequences to examine the evolutionary relationships of ant-nest beetles (Paussus spp). They found that the beetles are some of the fastest evolving animals on Earth. For example, the common ancestor of the 86 species that are native to Madagascar existed just 2.6 million years ago.

Curr. Biol.; (2014)