Biol. J. Linn. Soc. 96, 82–102 (2009)

A number of parasitic wasp species have independently evolved echolocation techniques to find host insects deep within trees.

Several species of parasitic wasp attack beetle larvae living inside wood, leading researchers to wonder how they find their prey. To this end, Nina Laurenne at the Museum of Natural History in Helsinki and her colleagues have surveyed the hammer-shaped antennal tips that these species whack against the trees. This hammering allows the wasps to locate the regions where they are wont to find their prey.

A phylogenetic analysis conducted by the researchers suggests that these hammers are not a one-off innovation and have appeared and disappeared during the course of evolution, seemingly in response to the needs of wasp species moving into this niche.