Confocal laser scanning microscopy and three-dimensional reconstruction delimit species in a taxonomically challenging group: a revision of the plant bug genus Anapus Stål, 1858 (Heteroptera: Miridae)

This paper provides a comprehensive revision of the Palearctic plant bug genus Anapus Stål, 1858. Despite a limited number of included species, identification in this group remains challenging due to significant intraspecific polymorphism in the coloration and body proportions. To tackle this issue, confocal microscopy was used to study the male genitalia, and three-dimensional reconstructions of the aedeagus were obtained for all valid species. Our results reveal advantages of these techniques in visualizing small and complex genital structures over traditional methods of taxonomic imaging. A detailed study of the male and female genitalia resulted in finding novel characters allowing for unequivocal species recognition. The differential diagnosis for the genus and a key to all species are given. Habitus photographs, illustrations of male genitalic structures, scanning micrographs of morphological structures, host and distributional information are provided for all species. Anapus longicornis Jakovlev, 1882 is synonymized with Anapus pachymerus (Reuter, 1881) and a lectotype for the latter species is designated. Anapus americanus Knight, 1959 is transferred to the genus Myrmecophyes Fieber, 1870.