Insects of Britain and Ireland: orders

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L. Watson and M. J. Dallwitz


Including Mallophaga, Siphunculata (= Anoplura). Bird Lice, Biting Lice (Mallophaga), Sucking Lice, Head Louse, Body Louse.

Adult insects. Exclusively parasitic (Mallophaga feeding on feathers or feathers and blood, Anoplura exclusively on blood); ectoparasitic on mammals (Anoplura, seemingly to the exclusion of bats and monotremes), or ectoparasitic on birds (Mallophaga). Minute to small; flightless. Body dorsiventrally flattened. Head prognathous; prolonged into a rigid beak (Siphunculata), or not rigidly beaked (Mallophaga). Mouthparts well developed; of the biting type (Mallophaga), or suctorial (Siphunculata); piercing (when sucking), or not piercing; more or less conforming to the generalized biting type (mandibulate in Mallophaga, with or without maxillary palps), or highly modified (tiny and difficult to interpret in Siphunculata, where they comprise a small, soft proboscis with internal teeth, which when feeding is everted to grip the host, and three piercing stylets; the whole assembly being borne on the unjointed, conical or rounded beak which constitutes the front of the head). Antennae inconspicuous; simple to complex; 3–5 segmented. Compound eyes vestigial or absent. Ocelli 0. Tarsi 1–2 segmented (the conspicuously one- or two-clawed tarsi adapted for clinging to the hosts). Abdomen not conspicuously appendaged; lacking clearly visible cerci; apparently 8–10 segmented (9 in Anoplura).

Larvae. Larvae feeding in the open; parasitic (on birds and mammals); with three pairs of segmented thoracic legs; without ventral abdominal prolegs; with paired anal prolegs (sometimes, with a terminal pair of abdominal claspers), or without anal prolegs. Larval head with a well sclerotized capsule. Development of larva into adult gradual; apterygote; not involving a pupal stage.

Classification. Subclass Pterygota; Division Endopterygota.

British representation. 12 families; genera 96; about 540 species.

Special features. The adults highly specialized, very dorsoventrally flattened, blind external parasites, which spend their whole lives clinging to their hosts via their modified tarsi.

Illustrations. • Pediculus humanus (Siphunculata): Shaw and Nodder (1795). Human Louse, and egg attached to a hair. • Pediculus humanus: Shaw and Nodder text. • Pediculus humanus: Shaw and Nodder text (cont.). • Pediculus humanus: Shaw and Nodder text (cont.). • Pediculus humanus: Shaw and Nodder text (cont.). • Mallophaga of domestic fowl: Lipeurus, Menopon. Lipeurus caponis. Menopon gallinae.

To view the illustrations with detailed captions, go to the interactive key. This also 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. Insects of Britain and Ireland: orders. Version: 16th May 2016.’.