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~ Dictyoptera, ~ Orthoptera s. lat.Cockroaches.
Adult insects. Phytophagous, saprophagous, consuming stored produce, and mycophagous (more or less omnivorous). Small to large; with hardened ‘elytra’ (q.v.), representing the fore-wings; capable of flight; with one pair of propellant wings (the hindwings). Body dorsiventrally flattened. Head hypognathous. Mouthparts well developed; of the biting type; conforming to the generalized biting type (with strong, toothed mandibles). Antennae conspicuous; simple; 15–35 segmented (i.e., “many-segmented”). Ocelli interpretable as 2 (being represented by two “ocelliform spots”). Wings four; markedly differently textured in the two pairs. Fore-wings leathery. Hind-wings larger than the fore-wings; markedly broader than the fore-wings; folded in repose. Wings with few cross-veins; more or less naked. Wings of the resting insect closed and directed backwards. Tarsi 5 segmented. Abdomen conspicuously appendaged at the rear; with cerci clearly visible at its tip; apparently 10 segmented (the segments distinguishable by their terga, 11 being absorbed into 10).
Eggs The eggs laid in batches within a protective case (ootheca).
Larvae. Larvae with three pairs of segmented thoracic legs; without ventral abdominal prolegs. Development of larva into adult gradual; exopterygote; not involving a pupal stage.
Classification. Subclass Pterygota; Division Exopterygota.
British representation. Blattidae, Blaberidae, Blattellidae (Psedomopidae); genera 6 (Blatta, Blattella, Ectobius, Supella, Periplaneta and Pycnoscelus being represented by natives or established residents, but representatives of about a dozen additional, mainly tropical genera are often imported with foodstuffs. Of the latter, beautiful, large green cockroaches of the genus Panchlora (not illustrated here) sometimes accompany fruit from the West Indies); about 10 species (plus about 20 casually occuring exotics).
Illustrations. • Resident British species: Burr. BLATTELLIDAE. 1, Ectobius lapponicus (Lapland cockroach), male; 2 and 2a, Ectobius panzeri; 3, Ectobius pallidus (Tawny cockroach), male; 4, Blattella germanica (German cockroach). BLATTIDAE. 5 and 5a, Blatta orientalis (Common Cockroach), male and elytra of female; 6, Periplaneta americana (American cockroach, Ship cockroach, American vagabond: very widely established in hothouses and warehouses); 7, Periplaneta australasiae (Australian cockroach: established especially in hothouses). S.L. Mosely's plate, from Burr (1897). • Ectobius lapponicus (Lapland or Dusky Cockroach: B. Ent. 556). • Ectobius lapponicus (detail: B. Ent. 556). • Ectobius lapponicus (dissections: B. Ent. 556). • Ectobius lapponicus (legend+text: B. Ent. 556). • Ectobius lapponicus (text: B. Ent. 556, cont.). • The British Ectobius species (Lucas). 1 and 2, Ectobius lapponicus (Dusky Cockroach), male (1) and female; 3, Ectobius perspicillaris Herbst (= E. lapponicus? ); 4 and 5, Ectobius panzeri (Lesser Cockroach), male (4) and female. From Lucas (1920), with approximate 1cm scale added. • Ectobius lapponicus (Dusky Cockroach): Stephens VI, 1835. • Periplaneta americana and P. australasiae (Lucas). 1, Periplaneta americana (American or Ship Cockroach), male; 2, Periplaneta australasiae (Australian Cockroach), male. From Lucas (1920), with approximate 1cm scale. • Periplaneta and Pycnoscelus (Lucas). 1, Periplaneta americana (American or Ship Cockroach); 2, Periplaneta australasiae (Australian Cockroach); 3, Pycnoscelus surinamensis (Surinam Cockroach). From Lucas (1920), with approximate 2cm scale. • Some commonly imported species: Burr. BLABERIDAE. 1, Rhyparobia maderae Fab., (from Madeira and West Africa); 2, Pycnoscelus surinamensis (Surinam cockroach: pan-tropical, persistent in warm situations); 3, Blaberus giganteus (West Indies). S.L. Mosely's plate, from Burr (1897).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: orders. Version: 14th April 2022. delta-intkey.com’.
