Review of the mite family Pachylaelapidae (Acari: Mesostigmata).

The family Pachylaelapidae Berlese, 1913 (Acari: Mesostigmata) includes a total of 16 valid and adequately described genera, namely Chaetodellus Mašán & Halliday, 2013, Elaphrolaelaps Berlese, 1910, Mirabulbus Liu & Ma, 2001, Neopachylaelaps Mašán, 2007, Olopachys Berlese, 1910, Onchodellus Berlese, 1904, Pachydellus Mašán, 2007, Pachyglobolaelaps Mašán, new genus, Pachylaelaps Berlese, 1888, Pachylaelapsoides Mašán, 2007, Pachyseiulus Moraza & Johnston, 1990, Pachyseius Berlese, 1910, Pachysphaerolaelaps Mašán, 2007, Paralaelaps Trägårdh, 1908, Pseudopachys Berlese, 1916 and Sphaerolaelaps Berlese, 1903. Three of these genera include subgenera, namely Elaphrolaelaps (Incisosternum) Elsen, 1974, Olopachys (Olopachylaella) Mašán, 2007 and Pachylaelaps (Longipachylaelaps) Mašán, 2007.The family is classified here into three subfamilies, Pachyseiinae Karg, 1971 including Pachyseius and Mirabulbus; Pachyseiulinae Mašán, 2007 including Pachyseiulus and Pseudopachys; and Pachylaelapinae Berlese, 1913, with all the other genera. Pachylaelapinae is further divided into three tribes, Pachylaelapini, Paralaelapini and Onchodellini. Almost half of the known genera are monotypic: Neopachylaelaps, Pachyglobolaelaps, Pachylaelapsoides, Pachyseiulus, Pachysphaerolaelaps, Pseudopachys and Sphaerolaelaps, while Onchodellus and Pachylaelaps are the largest genera in the family.Eleven genera that were provisionally classified as Pachylaelapidae cannot be reliably placed into a family on the basis of the available information, or have been incorrectly placed in the Pachylaelapidae: Actinoseius Berlese, 1916, Beaurieuia Oudemans, 1929, Brachylaelaps Berlese, 1910, Bulbogamasus Gu, Wang & Duan, 1991, Megalolaelaps Berlese, 1892, Meliponapachys Turk, 1948, Neoparasitus Oudemans, 1901, Pachylaella Berlese, 1916, Platylaelaps Berlese, 1905, Pseudolaelaps Berlese, 1916 and Zygoseius Berlese, 1916.New synonymies are established for Pseudoparasitus (Pseudopachys) parasitizans Berlese, 1916 (= Pseudopachyseiulus ignacii Moraza & Johnston, 1993) and Pseudopachys Berlese, 1916 (= Pseudopachyseiulus Moraza & Johnston, 1993). Brachylaelaps and Pachylaella are here considered as genera of Neoparasitidae and Macrochelidae respectively, rather than Pachylaelapidae. The genus Mirabulbus is redefined and transferred from Bulbogamasidae to Pachyseiinae. Paralaelaps and Elaphrolaelaps are provisionally placed together in the Pachylaelapinae and the new tribe Paralaelapini. Altogether 44 new combinations are proposed.Onchodellus slovacus Mašán and Pachyglobolaelaps hallidayi Mašán are introduced as new species. Mašán (2007a) described these species but did not designate holotypes for them, so their names are not available from that date.Replacement names are proposed for five junior homonyms: (1) Onchodellus michaelcostai Mašán & Halliday, replacement name for Pachylaelaps brevis Costa, 1971, junior homonym of Pachylaelaps brevis Berlese, 1920; (2) Onchodellus morazae Mašán & Halliday, replacement name for Pachylaelaps minutus Moraza & Peña, 2005, junior homonym of Pachylaelaps minutus Oudemans, 1901; (3) Pachylaelaps atlanticus Mašán & Halliday, replacement name for Pachylaelaps major Van Driel, Loots & Marais, 1977, junior homonym of Pachylaelaps (Paralaelaps) major Berlese, 1918; (4) Pachylaelaps schweizeri Mašán & Halliday, replacement name for Pachylaelaps latus Schweizer, 1961, junior homonym of Pachylaelaps (Platylaelaps) latus Berlese, 1905; and (5) Pachylaelaps similis Mašán & Halliday, replacement name for Pachylaelaps reticulata Hafez & Nasr, 1982, junior homonym of Pachylaelaps (Onchodellus) reticulatus Berlese, 1904.We provide a catalogue of the world species of Pachylaelapidae, which includes 253 named species (including synonyms), with details of their authorship, synonyms, nomenclatural and bibliographic details and generic placement.