Earwigs of Panama (Dermaptera)

Abstract The Dermaptera, or earwigs, is a small order of about 1900 species worldwide, of which about 450 are Neotropical. The Neotropical earwig fauna is not yet adequately known; it is likely to be very rich in species, having close affinities with the dermapterans of South Africa (genus Esphalmenus Burr, 1909, Pygidicranidae) and West Africa (genus Forcipula Bolivar, 1898, Labiduridae). Of the eight families of Dermaptera now recognized (Sakai 1982), two families (Apachyidae and Chelisochidae) are absent from the Neotropical region. The Holarctic region has a poor Dermaptera fauna (for example, only 26 species are known for the whole USSR; Bei-Bienko 1967); the number of species becomes even smaller in northern Mexico. Earwigs seem to prefer warm or hot moist tropical forests, particularly the tropical and subtropical forests of South America. Central America should prove to have a large Dermaptera fauna also. The ectoparasitic and wingless oriental Arixeniina and north African Hemimerina (two genera, ectoparasitic on murid rats: Hemimerus Walker, 18 71 and Araeomerus Maa, 19 74) are often considered separate suborders, distinct from true earwigs. Usually the latter can be recognized easily by the forceps at the end of the abdomen (Fig. 12.1). Whilst some other insects may have abdominal cerci, there is seldom any difficulty in recognizing an earwig as such. Some textbooks use the term ‘cerci’ for the forceps of earwigs, but it seems preferable to use ‘forceps’ because, in all adult and almost all immature earwigs, the forceps are composed of two unsegmented branches, which are not segmented as are normal cerci. The immatures of few earwigs have very long, segmented cerci (Diplatyidae), or partially segmented forceps (a few African Karschiellini, Pygidicranidae).