Ranatra
Ranatra chinensis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hemiptera
Suborder:	Heteroptera
Family:	Nepidae
Subfamily:	Ranatrinae
Genus:	Ranatra Fabricius, 1790

Ranatra is agenus of slenderpredatory insects of the familyNepidae, known aswater scorpions orwater stick-insects.^[1] There are more than 140Ranatra species found in freshwater habitats around the world, both in warm and temperate regions, with the highest diversity in South America (almost 50 species) and Asia (about 30 species, reviewed in 1972^[2]). Fewer are found elsewhere, but include several African, some in North America, three from Australia and three from thePalearctic, notably the relatively well-known EuropeanR. linearis.^[3] SinceRanatra belongs to the family Nepidae which in turn belongs to the orderHemiptera,Ranatra are considered "true bugs".

These brown insects are primarily found in stagnant or slow-moving water like ponds, marshes and canals, but can also be seen in streams.^[3] Exceptionally they have been recorded fromhypersaline lakes andbrackish lagoons.^[4]

The frontlegs of bugs inRanatra are strong and used to grasp prey. They typically eat other insects,tadpoles and small fish, which they pierce with theirproboscis and inject a saliva which both sedates and begins to digest their prey. They aresit-and-wait predators that reside among water plants and position themselves head-down with their grasping legs extended out to surprise passing prey.^[3] At least one species will also swim in open water at night to catchzooplanktonic organisms.^[5] Like other members in the family they have a long tail-likesiphon, or breathing tube, on the rear end of their body.^[5] The adult body length is generally 2–6 cm (0.8–2.4 in) depending on the exact species, and females average larger than males of the same species. The siphon is typically almost the same size, but varies from less than half the body length to somewhat longer. Two of the largest species are the East AsianR. chinensis and South AmericanR. magna.^[3][6]Ranatra do have wings and they can fly.^[4]

The adults are active year-round, except in extreme cold. Their eggs are positioned on plants just below the water surface, but in some species they can be placed in mud.^[3] The eggs typically take two to four weeks to hatch and the young take about two months to mature.^{[citation needed]}

• 
  Ranatra linearis
• 
  Ranatra chinensis
• 
  Ranatra crawling on human fingers

Among the four genera in the subfamilyRanatrinae,Austronepa andGoondnomdanepa are restricted to Australia.Cercotmetus from Asia to New Guinea resemblesRanatra, although the former has a distinctly shorter siphon.^[3]

TheGlobal Biodiversity Information Facility lists:^[7]

Data sources: i = ITIS,^[8] c = Catalogue of Life,^[9] g = GBIF,^[7] b = Bugguide.net^[10]

• Data related toRanatra at Wikispecies
• Media related toRanatra at Wikimedia Commons

• Nepidae
• Nepomorpha genera

• Articles with short description
• Short description matches Wikidata
• Articles with 'species' microformats
• All articles with unsourced statements
• Articles with unsourced statements from April 2018
• Commons link from Wikidata