Last week I wrote about mites that live alongside honey bees, eating and reproducing within their hives. There are many tiny animals that associate with social insects, and today’s new species are yet another example: termite-loving rove beetles from Cambodia (Kanao and Maruyama 2015).
Just like their hosts, termite-loving beetles are tiny, often less than 2 millimeters long, and don’t really look like conventional beetles. Their bodies are flattened and glossy, almost tear-drop shaped, with attractive woody shades. For small insects that spend most of their lives in complete darkness, they are surprisingly attractive.
What makes these beetles so amazing is, of course, their termite-loving predilection. “Loving” is a bit misleading – termite-loving beetles are social parasites, living off the hard work of their hosts. The termites eat wood, but in order to eat it they cultivate gardens of fungi which help to break down the wood’s tough chemical components, especially cellulose. The beetles can’t eat wood, but are happy to eat their way through the fungal gardens.
Whether this has any damaging effect on the termite colony is unknown, but there are far worse guests. Many animals that live in termite nests, including some rove beetles, are there to prey on the termites themselves. Just last month scientists described a new species of whip-spider that lives as a predator in termite mounds.
How do rove beetles manage to go undetected in a swarming termite colony? They don’t, at least, not entirely. The termites often notice the beetles, even feeling them with their antennae, but apparently cannot recognize them as intruders. Possibly the beetles secrete pheromones, chemical signals that mimic those produced by termites. This allows them to be accepted into the colony, despite being poor house-guests.
Kanao T. and M. Maruyama. 2015. Eight new species, a new record, and redescription of the genus Discoxenus Wasmann, 1904: The first record of termitophilous rove beetles in Cambodia (Coleoptera: Staphylinidae: Aleocharinae). Zootaxa 4044(2): 201-223.
Reveillion F. and P.O. Maquart. 2015. A new species of Charinus Simon, 1892 (Amblypygi, Charinidae) from termite nests in French Guiana. Zootaxa 4032(2): 190-196.