Nepidae
Water Scorpion ( Nepa cinerea)
Scorpio bugs ( Nepidae ) are a family of bugs (Heteroptera ) in the partial order of the water bugs ( Nepomorpha ). It includes 14 genera and 268 species. In Europe, five species are represented, two of which also occur in Central Europe.
Features
The medium to large bugs are 15 to 45 millimeters long. Your body varies from flattened and ovoid shaped to cylindrical with parallel side edges. In general, the animals are dull brown in color.
Her little head is usually used in the pronotum. The compound eyes are prominent in comparison to the other representatives of the water bugs and small on the anterior margin of the pronotum. Simple eyes ( ocelli ) are not trained. The short, tripartite sensors are ventrally inflected below the compound eyes and not visible from above. The second and sometimes the third antennal segment can bear finger-like projections. The equally tripartite and short labium is often curved. The pronotum is nearly square and rear, as the front edge are often indented. The triangular tag ( scutellum ) is large. The forewings have a large clavus and a membrane with weakly pronounced Flügeladerung, but many cells. The legs are long and slender and poorly adapted to swimming. The front legs are modified to catch legs, her thighs ( femurs ) are strongly thickened and have a ventral furrow, be included in the the rails ( tibia ). All tarsi eingliedrig. In the imagos no scent glands on the metathorax are formed, the nymphs they are missing on the abdomen. The Imagines the sternites of the abdomen are divided longitudinally. The subgenital plate is wide. The bug bear at the abdomen tip a long, slender breathing tube, which may be the same length, or even longer than the rest of the body of animals. The genitalia of the males are characterized by a short Conjuctiva and a stiff Endosoma.
The eggs, unique among the bugs, two to 26 breathing tubes at the anterior pole.
Distribution and habitat
The family is distributed worldwide and has its main distribution in the tropics. Most scorpion bugs inhabit standing waters. The genus Ranatra hold on usually between parts of plants or submerged plants. The species of the genus Nepa and Curicta be found in shallow, muddy paints or slow-flowing rivers and streams with little vegetation. Species of the genus have been found under stones Goodnomdanepa of shallow streams.
Way of life
Scorpio bugs feed as predatory ambush predator. Their prey includes tadpoles, juveniles, amphipods, isopods, water fleas, insect larvae and various other invertebrates. Unlike the other representatives of the water bugs, the scorpion bugs breathe with the help of her breathing tube to stretch over the water surface into the air. The bugs move usually only run slowly at the bottom of bodies of water or climb on aquatic plants.
Taxonomy and systematics
Pierre André Latreille in 1802 brought the first described by Carl Linnaeus genus Nepa as Nepariae in the family rank. Menke & Strange led in 1964 a revision of the family above the genus level by and divided the family into two subfamilies Ranatrinae and Nepinae, as this is considered valid from today's perspective. The elevation of these two subfamilies into independent families by De Carlo in 1967 was rejected in 1979 by Menke again. After Stys & Jansson (1988 ), whose classification is still followed today, ask yourself the subtaxa the family as follows:
- Subfamily Nepinae Tribus Curictini Genus Curicta (New World)
- Subfamily Ranatrinae Tribus Austronepini Genus Austronepa (Australia)
- Genus Goodnomdanepa (Australia)
- Genus Cercotmetus ( Orientalis, Australasia )
- Genus Ranatra (worldwide)
In Europe, the following types are used:
- Nepa anophthalma Decu, Gruia, Keffer & Sarbu, 1994
- Water Scorpion ( Nepa cinerea) Linnaeus, 1758
- Nepa sardiniensis Hungerford, 1928
- Stick bug ( Ranatra linearis ) (Linnaeus, 1758)
- Ranatra unicolor Scott, 1874