New species and new records of Cosmolaelaps Berlese (Acari: Laelapidae) from Russia, with a review of the Russian species of the genus Author Joharchi, Omid Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, Semakova Str. 10, 625003 Tyumen, Russia. Author Döker, Ismail 0000-0002-2741-4946 Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, Semakova Str. 10, 625003 Tyumen, Russia. & Cukurova University, Agricultural Faculty, Department of Plant Protection, Acarology Laboratory, 01330, Adana, Turkey. https: // orcid. org / 0000 - 0002 - 2741 - 4946 (Joharchi) https: // orcid. org / 0000 - 0002 - 1412 - 1554 (Döker) https: // orcid. org / 0000 - 0003 - 2831 - 7213 (Khaustov) Author Khaustov, Vladimir A. Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, Semakova Str. 10, 625003 Tyumen, Russia. text Zootaxa 2022 2022-05-06 5133 4 486 508 journal article 55626 10.11646/zootaxa.5133.4.2 0cd92d63-eeac-48d6-9c9d-270f866de7d3 1175-5326 6530956 BD6A434A-21D7-49FC-A09F-FEF4BC740B14 Cosmolaelaps chianensis (Gu) ( Figures 1–7 ) Hypoaspis chianensis Gu, 1990: 441 . Hypoaspis ( Cosmolaelaps ) hefeiensis Xu & Liang, 1996: 193 (junior synonymy by Ma, 2006: 23 ; Bai & Ma, 2012: 558 ). Hypoaspis ( Cosmolaelaps ) hefeiensis .— Bei et al ., 2003: 648 . Hypoaspis chianensis .— Ren & Guo, 2008: 329 . Cosmolaelaps chianensis .— Moreira et al ., 2014: 319 ; Keum et al ., 2017: 486 . FIGURES 1–7. DIC micrographs of Cosmolaelaps chianensis (Gu) , female. 1, idiosoma in dorsal view, enlarged section not to scale; 2, idiosoma in ventral view; 3, sternal shield; 4, general view of opisthogastric area; 5, chelicera; 6, dorsal aspect of femur, genu and tibia leg I; 7, ventral aspect of femur, genu and tibia leg I. Specimens examined .Ten females and five males , National forest, Sakhalin Island, Russia , 46°57'39"N 142°45'28"E , 9 August 2021 , O. Joharchi coll., in the nest of Myrmica sp. ( Hymenoptera : Formicidae ) (in TUMZ). Remarks . Cosmolaelaps chianensis was described from China ( Gu, 1990 ). It has been found associated with Mus pahari Thomas ( Rodentia : Muridae ). The description of this species is brief and both the description and illustrations lack many important details. Ma (2006) considered that Cosmolaelaps hefeiensis is a junior synonym of C . chianensis . However, Ma (2006) did not provide any explanation for this decision, nor did he provide the details of the examined specimens. Cosmolaelaps hefeiensis was also described from China ( Xu & Liang, 1996 ). It has been found from moss ( Xu & Liang, 1996 ) and this species also has been recorded from soil in Republic of Korea ( Keum et al ., 2017 ) and Russia ( Marchenko, 2017 ). By comparing the descriptions and figures of these two species, we found some distinguishing morphological differences: (1) dorsal shield setae J5 and Z5 more or less similar in length, and j1 considerably shorter than j 2 in C . hefeiensis (see Xu & Liang, 1996 and Fig. 1 of current study), while in C . chianensis setae Z5 are obviously longer than J5 and j1 is similar length to j2 (see Fig. 1 in Gu, 1990 ); (2) body size 395 long, 255 wide in C . chianensis (see Gu, 1990 ), while in C . hefeiensis size of body larger, especially its width (484–560 long, 345–391 wide) (see Xu & Liang, 1996 ). Our efforts to see type material of these two species were not successful so, in this study we follow Ma’s (2006) treatment and provisionally retain these two species as synonyms until further comparative studies clarify their relationship. Our concept of the species is based on that of Xu & Liang (1996) and the diagnosis given as follows is based primarily on specimens from Russia , but also in comparison with the original description of C . hefeiensis . Our specimens agree very well with the description given by Xu & Liang, 1996 for Cosmolaelaps hefeiensis . The species is easily recognised by the long and thick setae of the dorsal shield (most setae long enough to reach well past the base of next posterior seta) ( Fig. 1 ), j1 , z1 , Z5 simple and without knob at their bases, j1 apically bent (hook shaped) and Z5 shorter than J5 ( J5 ≈ 1.5 x Z5 ) ( Fig. 1 ); sternal setae short, at most reaching base of next setae ( Figs 2, 3 ), soft opisthogastric cuticle bearing 16 pairs setae, Jv4–5 and Zv4–5 thickened ( Figs 2, 4 ), post-anal seta slightly thicker and longer than para-anal setae ( Figs 2, 4 ), fixed digit of chelicera of female with six teeth, including three large proximal teeth (posterior to pilus dentilis) ( Fig. 5 ), spatulate seta on legs absent, genu and tibia of leg I without conspicuously thickened seta ( Figs 6, 7 ).