By Susan Milius
They don’t surf, but caterpillars found only in Hawaii are the first insects known to feed and grow as readily in water as on land.
Other land insects can endure a dunking. And other aquatic ones can survive a dry spell stranded out of water, says evolutionary biologist Daniel Rubinoff of the University of Hawaii at Manoa. But he and a colleague now describe amphibious habits of larvae in 12 new species in the moth genus Hyposmocoma. Young of each species can thrive both underwater in rushing streams and exposed to air on rocks poking out of the water.
Hyposmocoma moths live only in the Hawaiian islands, and most species in the genus spend their caterpillarhood exclusively on land before flitting away as full-grown moths. Yet genetic analyses show that at least three times within the genus, landlubber lineages have independently evolved amphibious caterpillars, Rubinoff and University of Hawaii at Manoa colleague Patrick Schmitz report online March 22 in the Proceedings of the National Academy of Sciences.