What it looks like: 12.5-15.5mm in length. This beetle can be
easily identified by its distinctive markings. Its body is brown
with pale marks on the elytra, close to the tip of the abdomen.
Its head is pale with transverse brown markings. It is ovoid and
streamlined, with long, powerful hind legs for swimming. The
elytra of males and females are surprisingly different, those of
the females appearing scalloped, with long, scooped out
impressions. Where you'll find it: This species ranges from
Alaska to southern California and as far east as the Rocky
Mountains. In California it is mainly found in cooler, northern
areas. Natural History: These beetles are strong swimmers mainly
found sculling in the open waters of beaver ponds. They have
also been found in vernal pools in the Santa Barbara area.