|Water scavenger beetles reach body lengths of 4-9 mm. Their bodies are oval-shaped, with a very flat underside. They have a slightly metallic sheen, are deep black in colour and shimmer slightly bronze when seen in light.|
Adults have short, club-shaped antennae. Their mouthparts (maxillary palpi) are elongated, yellowish to reddish-brown in colour and hair-like (filiform) and may be mistaken for antennae. The maxillary palpi like the antennae often have dark ends. On the wing covers (elytra) are 10 stripes of fine, puncture-like points. These stripes, which are lengthwise and become furrow shaped at the rear end, are the main distinguishing feature of the water scavenger beetle. Additional rows from irregular posited series of points appear in the space between the rows from regular posited points. The legs of the beetle are yellowish, yellow-brown or rust-colored. The tarsi appear reddish brown to dark brown in colour.
The hind legs have long hairs that aid in swimming. The water scavenger beetle prefers to live in and on smaller bodies of waters with sufficient sunlight. They are often found (as adults or larvae) floating on the surface of salt water or brackish water (mixture of river and sea water). The adults eat rotten plant debris. They surface for air head first and trap air to breath under their wing covers (elytra) and "row" themselves along by alternating the hind legs, wiggling from side to side as they swim. Their eyesight is not very developed. Therefore, it is possible for the beetles to land on? reflective surfaces (wet or shiny car roofs, windows, etc.) having confused them with open waters.
After mating, the oviposition of the females happens in cocoons near the surface of water where the eggs are glued to water plants. Approximately 8-10 days later the larvae (with body lengths of 3-4 mm) hatch. They increase rapidly in size . The larvae feed (starting at the lastest three days after hatching) ) on smaller aquatic animals, and are even prone to cannibalism. In water they catch floating prey with their clamp-like mouthparts (mandibles), hold them tight and swim with the living prey intact to the water’s edge. Having found a good landing point, they put their abdomen on the solid ground and move themselves backwards with tracking the prey over the shore. They crush them with their mandibles. The exoskeleton of the prey gets covered over and over again with intestinal secretions. The prey is then kneaded into a pulpy mass which can be sucked up by the larvae. This takes 2-3 minutes. Finally the larva leaves the emptied skeleton and creeps forward back into the water. Cannibalism can become so prevalent among the larvae that they prefer to eat each other than to attack other insects.
|Common names||Water Scavenger Beetle|
|German names||Braunfüßiger Wasserkäfer|
|Danish names||Almindelig vandkær|
|Finnish names||Uurrevedensuosija, Uurrevesiäinen|
|Author||C. Linnaeus, 1758|
North Europe (British Isles (United Kingdom (Great Britain (England (English Midlands (East Midlands (Leicestershire), West Midlands (Worcestershire)), South England (Southeast England (Berkshire))))), Ireland), Germany (West Germany (North Rhine-Westphalia)), Scandinavia (Norway, Sweden, Denmark), Fennoscandia (Finland (Åland Islands)), Baltic region (Baltic States (Estonia, Latvia))), West Europe (Austria, France, Switzerland, Benelux (Belgium, Netherlands, Luxembourg)), South Europe (Italy (Italy Islands (Sicily, Sardinia), North Italy, South Italy), Iberian Peninsula (Spain, Portugal)), Southeast Europe (Romania, Yugoslavia (Bosnia and Herzegovina)), Central Europe (Poland, Czech Republic (Moravia, Bohemia), Slovakia), East Europe (Ukraine, Belarus)Asia
Far East (East Asia (China, Japan)), South Asia (Afghanistan), North AsiaRussia
Canada (Ontario), USA (Washington, Colorado, New Hampshire)
Ecozones: Palaearctic, Nearctic
Pleistocene (Middle Pleistocene, Upper Pleistocene)
|Countries||Afghanistan, Austria, Belarus, Belgium, Bosnia and Herzegovina, Canada, China, Czech Republic, Denmark, Estonia, Finland, France, Germany, Ireland, Italy, Japan, Latvia, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Russia, Slovakia, Spain, Sweden, Switzerland, USA, Ukraine, United Kingdom|
|Distr. info||Aquatic Insect|
|Links and References||Hydrobius fuscipes in faunaeur.org|
Hydrobius fuscipes in itis.gov
Hydrobius fuscipes in dyntaxa.se
Hydrobius fuscipes in Wikipedia (English)
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