Nepa is a genus belonging to the family Nepidae, known as water scorpions. Species are found in freshwater habitats in the Northern Hemisphere.[2][3][4]
They are oval-bodied, aquatic insects with raptorial front legs. Like other members of the Nepidae, they have a pair of nonretractable cerci-like breathing tubes on the terminal abdominal segment, a characteristic which readily distinguishes them from the Belostomatidae. Their primary staples are other insects and small aquatic vertebrates. They can inflict a painful bite when handled.[5]
Among these, the type speciesN. cinerea of Europe, northern Africa and northern Asia and N. apiculata of eastern North American (Canada and United States), are widespread.[2][5] The remaining have restricted ranges in Corsica, Sardinia, Romania, Morocco and northeastern Asia.[2][4] One of these, N. anophthalma, is the only cave-adapted species in the family Nepidae, found in Movile Cave.[4]
^ abcdS.L. Keffer; J.T. Polhemus; J.E. McPherson (1990). "What Is Nepa hoffmanni (Heteroptera: Nepidae)? Male Genitalia Hold the Answer, and Delimit Species Groups". Journal of the New York Entomological Society. 98 (2): 154–162.
^ abcdVasile Decu; Magdalena Gruia; S. L. Keffer; Serban Mircea Sarbu (1994). "Stygobiotic Waterscorpion, Nepa anophthalma, n. sp. (Heteroptera: Nepidae), from a Sulfurous Cave in Romania". Annals of the Entomological Society of America. 87 (6): 755–761. doi:10.1093/aesa/87.6.755.