British Insects: the Families of Hemiptera
| British Insects: the Families of Hemiptera | |
Water-scorpion and Water Stick-insect.
Salient features of adults. Foraging under water.
Predacious (on arthropods, tadpoles and small fish). Large; 18–22 mm long (Nepa cineria), or 30–35 mm long (Ranatra linearis); fliers; swimming and moving under water the right way up; relatively stout bodied (Nepa cineria), or with narrow-elongate bodies (Ranatra linearis); conspicuously stilt-legged (Ranatra linearis), or not stilt-legged (Nepa cineria). Rostrum clearly separated ventrally from the prosternum by a sclerotized gula. Antennae inserted underneath the head and much shorter than it, generally invisible from above; non-aristate. Ocelli absent. Fore-wings well developed; in the resting insect lying more or less flat over the abdomen; differentiated into a basally thickened and a distally membranous region; with a clavus. Fore-legs modified and raptorial. The abdomen terminating in a long, bristle-like respiratory siphon (this comprising two filaments, which may become detached as in the illustration).
Comments. With conspicuously modified, raptorial forelegs, and the abdomen terminating in an elongated respiratory siphon.
Taxonomy. Suborder Heteroptera; Notonectoidea.
British representation. Genera 2; 2 species.
Illustrations: • Ranatra linearis (Linear Water-scorpion: B. Ent. 281). • Ranatra linearis (dissections: B. Ent. 281). • Ranatra linearis (legend+text: B. Ent. 281). • Ranatra linearis (text: B. Ent. 281, cont.). • Ranatra linearis (Shaw and Nodder, about 1802). • 'The Great Surinam Nepa' (Exotic species, Shaw and Nodder, about 1798).
The interactive key offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: the families of Hemiptera. Version: 9th April 2007. http://delta-intkey.com’.
