Dermaptera

(Earwigs)

Susan M. Rankin and James O. Palmer

Allegheny College

The Dermaptera (earwigs) comprise a small, relatively old, hemimetabolous order of insects characterized in their external anatomy by paired cerci (forceps) at the posterior end, and (in winged forms) short tegmina incompletely covering hind wings that are also unique structurally (Fig. 1). Behaviorally, earwigs are thigmotactic, nocturnal, and subsocial, in a system whereby the female parent broods, grooms, and defends eggs and young nymphs (Fig. 2). Internal anatomy is typical of orthopteroids, except that the corpora allata have undergone fusion to a single median structure, and the paired ovaries are primitively polytrophic (i.e., each follicle contains an oocyte and a single nurse cell).

Earwigs are members of the orthopteroid assemblage and have a strong sister-group relationship with the Dictyoptera; they also may be closely related to the Grylloblattodea. Four suborders are generally recognized, and of the three extant ones, the Hemimerina and Arixinina are small groups of viviparous ectoparasites of vertebrates; most species of earwigs are oviparous members of the third group, the Forficulina. Typically, classification schemes have relied on features of the

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