Review of the genus Holostaspis Kolenati, 1858 (Acari: Laelapidae)

Mites in the genus Holostaspis Kolenati, 1858 (Acari: Laelapidae) are usually found in association with ants (Hymenoptera: Formicidae). In this paper we review the genus based on examination of six species from Slovakia, namely H . ambigua sp. nov., H . collina (Huhta & Karg, 2010), H . flexuosa (Michael, 1891) comb. nov., H . isotricha Kolenati, 1858, H . montana (Berlese, 1904) and H . oophila (Wasmann, 1897). We also carried out a careful study of the published work on Holostaspis and related genera, and examined types in the Berlese Acaroteca and other collections. Seven species previously described under the names Hypoaspis ( Holostaspis ) and Holostaspis are transferred to other genera— H . ( H .) brevidentis Karg, 1978 = Pseudoparasitus brevidentis (Karg, 1978) comb. nov., H . ( H .) chelaris Teng, Zhang & Cui, 1992 = Euandrolaelaps chelaris (Teng, Zhang & Cui, 1992) comb. nov., H . ( H .) metapodalii Karg, 1978 = Gymnolaelaps metapodalii (Karg, 1978) comb. nov., H . mooni Keum, Jung & Joharchi, 2017 = Hypoaspisella mooni (Keum, Jung & Joharchi, 2017) comb. nov., H . ( H .) serpentis Karg, 1979 = Hypoaspisella serpentis (Karg, 1979) comb. nov., H . ( H .) tridentata Karg, 1979 = Gymnolaelaps tridentatus (Karg, 1979) comb. nov., and Holostaspis ( Holostaspis ) marginedentatus Tragardh, 1910 is transferred to Glyptholaspis (Macrochelidae). Based on features of the type specimens (deposited at the Berlese Collection in Florence), the morphological concept of Myrmonyssus ( Laelaspulus ) acuminatus Berlese, 1903 is revised and the systematic status of the subgenus is re-evaluated. The monobasic Laelaspulus Berlese, 1904 is now removed from synonymy with Myrmozercon Berlese, 1902 and newly considered as a junior synonym of Holostaspis . Another four revised species, originally classified in Laelaps Koch, Myrmozercon Berlese or Hypoaspis Canestrini, are transferred into Holostaspis—L . flexuosa Michael, 1891 = Holostaspis flexuosa (Michael, 1891) comb. nov., M . iranicus Babaeian & Nemati, 2014 = Holostaspis iranica (Babaeian & Nemati, 2014) comb. nov., M . michaeli Joharchi, 2013 = Holostaspis michaeli (Joharchi, 2013) comb. nov., and H . submontana Bai, Gu & Chen, 1994 = Holostaspis submontana (Bai, Gu & Chen, 1994) comb. nov. A complete list of all species formerly classified in Holostaspis is presented, with details of their current placement. An identification key for the species now included in Holostaspis is also provided.