Get to Know a Species: Belostomatidaes aka Waterbugs
A male waterbug with eggs on its back. Photo credit: Tom Schulz, National Park Service
Belostomatidae is a family of freshwater hemipteran insects, known as giant water bugs or toe-biters. Abedus indentatus is our local Southern California species averaging.1.5 inches in size but other species can grow as large as 4.5 inches.
Interesting Facts About Waterbugs:
In a bit of role reversal, the eggs are typically laid on the male's wings! Males keep their babies moist, clean and safe from predators. He carries them until they hatch, which is usually at the end of summer, so now is a likely time to find nymphs in the local streams. Males can’t mate during egg duty, but females are free to!
Giant water bugs dine on a variety of aquatic life, including tadpoles, small fishes, insects, and other arthropods. Some are known to kill prey many times their own size. Grasping victims by “raptorial” front legs, they inject venomous digestive saliva into their victim and suck out the liquefied remains.
Giant water bugs can deliver a painful (though nontoxic) bite between the toes of unsuspecting human feet. This explains one of their common names: toe-biter!
Giant water bugs are known to play dead if removed from water. And, if startled, can emit a smelly fluid from their anus.
One species of giant water bug, Lethocerus indicus, is boiled in saltwater or fried and eaten by diners in South and Southeast Asia as a specialty cuisine.
Aquatic invertebrates such as the Abedus indentatus can tell us a lot about water quality. They often react strongly and predictably to changing water conditions. Monitoring fish and aquatic invertebrates can reveal long term impacts to aquatic systems, whereas traditional water quality measurements might indicate a moment in time, such as after a rainstorm.
Aquatic invertebrates can tell us a lot about long term water quality of a stream. Photo credit: Bernhard Yin