Although they are found in my home state of Ohio, I most often see these cool beetles when I retrieve my minnow traps in southern Illinois.
This is a decent-sized insect with an adult maximum length of about 1-1/2 inches. It’s body is streamlined and oval in shape.
Predaceous Diving Beetles prefer quiet water at the edges of ponds and streams, where they float gently among weeds. Before diving, they trap air between their wings and body, which prolongs their time spent under water.
Their hindlegs are fringed with hairs and flattened for swimming; when swimming, they kick both hind legs simultaneously. Not only are they good swimmers, but they are also strong fliers that can fly away to a new waterway if the pond they live in dries up.
Fierce predators, these beetles do not hesitate to attack prey larger then themselves, including small fish, tadpoles and frogs. Their sharp jaws inject enzymes that digest their prey, so that the juices can be ingested by the beetle.
Species in this genus of beetle are edible and were enjoyed both in pre-settlement days and on tacos in present-day Mexico. They have been “farmed” for human consumption in various parts of Asia and have been used medicinally in China.