Water Scorpion

Name for a large aquatic bug, belonging to the family Nepidae, with eight genera divided into two subfamilies, i.e. Nepinae (broad-bodied water scorpions, usually oval or leaf-shaped) and Ranatrinae (slender, stick-like water scorpions), of which six species are known in Thailand: belonging to the Nepinae subfamily are Laccotrephes rubber and Nepa apiculata; in the Ranatrinae subfamily are Cercotmetus sp., Ranatra filiformis, Ranatra fusca and Ranatra varipes. This predatory insect has a blackish, either leaf-shaped or a slender, stick-shaped body (fig.), depending on the species. Individuals of the slender species are also known as Water Stick-insects (Ranatra sp.). All have enlarged, pincer-like front legs, used for capturing prey. At the end of its abdomen it has a long breathing tube, which actually consists of a pair of half-tubes, capable of being locked together, and which at first glance resembles the tail of Whip Scorpions (fig.). Water Scorpions are found beneath the water surface, in the mud of ponds and stagnant water, or on aquatic vegetation such as water weeds. They are commonly found in rice paddies, where they are nicknamed toe-biters (fig.). The slender, stick-shaped species of the genus Ranatra, such as Ranatra linearis, are sometimes called Needle Bugs or Water Stick Insects. Their generic name in Thai is muan maengpong nahm. See also maengpong and List of Thai Insect Names. 回