Marsh Beetle

soil along the margins of streams, or are aquatic. Their habits are not well known.


Identification: Body oval or elongate-oval. Legs very long, strongly developed, claws large. Antennae short, most segments broader than long, usually concealed. Pubescence dense, low-lying, or absent. Front coxae transverse. Black, brown or dull gray. 1-8 mm.

These beetles are usually found on partly submerged sticks and stones in moving water or riffle areas of streams. They hang on firmly with their stout claws or creep slowly over the surface but do not swim. If a stick or stone is removed from the water and placed in the sun to dry, these beetles will be seen to move and can be captured — they are very difficult to see unless they move. Some adults are terrestrial and plant-feeding. Larvae are aquatic.

WATER-PENNY BEETLES Family Psephenidae Identification: Oval, flattened, black or brownish. FW broadest posteriorly, loosely covering abdomen. Dorsal surface sparsely pubescent, ventral surface densely pubescent. Abdomen with 5-7 ventral segments. 4-6 mm.

Water-penny beetles occur on vegetation along streams and on partly submerged rocks in riffles. Larvae are found on the underside of stones in rapidly flowing water; they are brownish, greatly flattened, and nearly circular, hence the common name of the group. Adults and larvae are plant feeders.


Identification: Form distinctive: body oval to cylindrical, legs long, strongly developed, claws large. Black to grayish. Antennae short or moderate in length, clubbed or threadlike. 1-8 mm.

Most riffle beetles occur on stones, logs, and other debris in flowing water; a few are terrestrial. The aquatic species spend most of their lives under water. Larvae are aquatic; some are long and slender, but others are flat and oval and resemble larvae of water-penny beetles.

0 0

Post a comment