Hello,

That looks like a Predaceous Diving Beetle, Dytiscus sp. (Coleoptera: Dytiscidae).

Adult beetles are 1/4 to 1-3/16 inches long, ovate, smooth, and have shining black bodies. There is a yellow margin around the front of the head, sides of the thorax and wing covers. Antennae are threadlike and prominent, with the hind legs longest and flattened to serve as oars in swimming. The beetle utilizes air trapped under its wing covers (elytra) to stay submerged for long periods. They are attracted to light, often migrate from one pond to another. They are strong fliers and occasionally find their way to nearby homes, yards and gardens. The larval stages are called water tigers. See

Unlike other water beetles which move their legs alternately when swimming, these beetles stroke them together like oars. They can be collected by sweeping submerged vegetation in streams and ponds with a dip net. Both adults and larvae are predaceous. Their sharp hollow mandibles (jaws) are used to inject paralyzing and digestive fluids into their prey and to draw out the liquid contents. They attack aquatic insects and fish, and have the ability to regenerate lost parts to some extent. Larvae crawl to shore to pupate in the soil and hibernation occurs in the water as an adult or larvae. There is one generation per year, and adults can live several years. There are 41 genera and 476 species of dytiscids in North America.

Regards,

Howard