Protoribates Berlese, 1908

Chen, Shujing Xu Yannan & Chen, Jun, 2020, New species and records of oribatid mites of the genus Protoribates (Acari Oribatida, Haplozetidae) from China, Zootaxa 4772 (3), pp. 469-511 : 470-471

Genus Protoribates Berlese, 1908

Protoribates Berlese, 1908: 1 ; Weigmann et al., 1993: 54; Bayartogtokh, 2010: 248; Walter & Latonas, 2013: 484 .

Xylobates Jacot, 1929: 429 ; Weigmann et al., 1993: 54 (synonymy).

Styloribates Jacot, 1934: 61 ; Subías, 2004: 206 (synonymy).

Alloribates Banks, 1947: 113 . Marshall et al., 1987: 266 (synonym of Xylobates ).

Brasilobates Pérez-Íñigo & Baggio, 1980: 135 ; Subías, 2004: 206 (synonymy).

Glaberoribates Tseng, 1984: 62 ; Subías, 2004: 206 (synonymy).

Octodurozetes Mahunka, 1993: 227 ; Subías, 2004, online version 2015: 427 (synonymy).

Type species: Oribates dentatus Berlese, 1883

Diagnosis. Haplozetidae with pteromorphs movable; discidium present, custodium present or not; notogaster usually with four pairs of small porose areas, rarely three; ten pairs of notogastral setae usually short or minute, rarely long; bothridial setae with lanceolate head, sometimes setiform or with clubbed head; lamellae located dorsolaterally, narrow; sublamellae present; prolamellae rarely present; tutorium short, ridge-like; anterior notogastral margin present; five pairs of genital setae, rarely four; one pair of aggenital setae; two pairs of anal setae; three pairs of adanal setae; legs usually monodactylous or heterotridactylous, rarely bidactylous.

Remarks. The history of taxonomic study on the genus Protoribates is complex. Banks (1947) established the genus Alloribates with Alloribates singularis as type species. Then, Marshall et al. (1987) considered it as a synonym of Xylobates Jacot, 1929 without any remarks. Weigmann et al. (1993) redescribed the type species of the genus Protoribates , P. dentatus ( Berlese, 1883) and considered Xylobates Jacot, 1929 as a junior synonym of Protoribates .

Jacot (1934) established the genus Styloribates with Styloribates pectinatus as type species, and then Balogh (1961) regarded it as a synonym of Scheloribates . Woolley (1968) proposed a new combination Xylobates pectinatus ( Jacot, 1934) , regarding Styloribates pectinatus as a species of Xylobates . Lee & Pajak (1990) revoked Styloribates from the synonym of Scheloribates because of the presence of tutorium (tutorium absent in Scheloribates ). Subías (2004) listed it as a junior synonym of the Protoribates and listed the type species Styloribates pectinatus as a synonym of P. lophothrichus ( Berlese, 1904) . According to the description and illustration of the type species Styloribates pectinatus , we think that it is similar to P. dentatus ( Berlese, 1883) , the type species of Protoribates , in having long adanal setae ad 1 and short ad 2, and femora II spur-like sharpened ventroanteriorly, which are diagnostic characters of P. dentatus and is different from P. lophothrichus (see Miko et al., 1994). We think that it is reasonable to list Styloribate s as a junior synonym of Protoribates . Styloribates pectinatus Jacot, 1934 may be a synonym of P. dentatus ( Berlese, 1883) , but additional research is necessary.

Jacot (1936) established the genus Propeschelobates with Oribata albida ( Ewing, 1908) as type species, and then Balogh (1961) regarded it as a synonym of Scheloribates . Lee & Pajak (1990) revoked the synonym from Scheloribates and considered it as a junior synonym of Styloribates . Subías (2004) listed it as a junior synonym of Protoribates and later in 2017, he listed it as a junior synonym of Indoribates (Haplozetes) Willmann, 1935 in his world catalogue of oribatid mites. Considering the presence of saccules rather than porose areas on notogaster in Propeschelobates , we disagree with the viewpoint that Propeschelobates is one of the synonyms of Protoribates .

Mahunka (1993) established the genus Octodurozetes with Octodurozetes berndhauseri as type species in having the structure of lamellae complex (prolamellae present) and the insertions of the lamellar setae (medial to lamellar ends) differing from Xylobates , but Subías (2004) listed it as a junior synonym of Perxylobates Hammer, 1972 . Corpuz-Raros (2009) regarded it as a valid genus because of the presence of the anterior notogastral margin (anterior notogastral margin absent in Perxylobates ). Subías (2004, online version 2015) listed Octodurozetes as a junior synonym of Protoribates in 2015. In fact, as Ermilov & Anichkin (2011b) stated, several species of Protoribates , such as P. bayanicus Bayartogtokh, 2000 , P. brevisetosus ( Fujita, 1989) , P. capucinus Berlese, 1908 , P. cattienensis Ermilov & Anichkin, 2011 , P. geonjiensis Choi, 1994 , P. kumayaensis Nakamura, Fukumori & Fujikawa, 2010 , P. nagaroensis ( Fujita, 1989) and P. lankaensis Ermilov, Khaustov & Joharchi 2019 , have lamellar setae inserted medially to lamellar ends. Although Ermilov & Anichkin (2011b) considered that Octodurozetes can be distinguished from Protoribates only by the presence of prolamellae, several species described in Protoribates later, such as P. heinrichi Ermilov, Sandmann & Scheu, 2019 , P. lemensis Ermilov & Tolstikov, 2015 and P. prolamellatus Ermilov, Sandmann & Scheu, 2019 also have prolamellae. Thus, we support the viewpoint that Octodurozetes is one of junior synonyms of Protoribates .

Kulijev (1978) established the genus Triaungius with Scheloribates fallax Kulijev, 1968 as type species. Subías (2004) regarded it as a subgenus Protoribates (Triaungius) in which the legs of species are heterotridactylous, and proposed two synonyms: Brasilobates Pérez-Íñigo & Baggio, 1980 = Protoribates (Triaungius) Kulijev, 1978 and Glaberoribates Tseng, 1984 = Protoribates (Triaungius) Kulijev, 1978 . Brasilobates was established by Pérez-Íñigo & Baggio (1980) with Brasilobates bipilis as type speices. They stated that the genus is similar to Xylobates , but differs from the latter by heterotridactylous legs and nine pairs of notogastral setae, by which we think that this is rather an identification tool than a character to establish a genus. In fact, according to the description and illustration of the type species Brasilobates bipilis , we found it is very similar to P. dentatus , only differing from the latter in having nine pairs of notogastral setae (vs. ten pairs of notogastral setae), setae le and in smooth (vs. setae le and in barbed), adanal setae ad 1 smooth (vs. adanal setae ad 1 barbed). We tend to regard B. bipilis as a synonym of P. dentatus ( Berlese, 1883) , but additional research is necessary. Glaberoribates was established by Tseng (1984) with Glaberoribates urbanlus as type species, but the only difference we could find between Glaberoribates and Protoribates is the number of notogastral setae: seven to eight pairs in the former and ten pairs in the latter, by which we think is not enough to establish a genus. Therefore, we support the proposals for these two synonyms by Subías (2004). We also noticed that after 2014 (including 2014), in the world catalogue of oribatid mites, Subías corrected the spelling “ Triaungius ” as “ Triaunguis ”, which may be because of the use of “ Triaunguis ” in Corpuz-Raros (2013). Although “ Triaunguis ” seems more idiomatic for expressing the 3-clawed generic diagnosis, the original spelling “ Triaungius ” in Kulijev (1978) should be reserved.

Weigmann et al. (1993) reviewed the Berlese’s opinions of Protoribates ( Berlese, 1908; Berlese, 1916) and Pérez-Iñigo’s opinion of Transoribates ( Pérez-Iñigo, 1992) and summarized that as believeing the genus Protoribates (sensu Berlese, 1916) was an invalid name, Pérez-Iñigo (1992) established a new genus, Transoribates with Protoribates latus Mihelčič, 1965 as type species. Walter & Latonas (2013) compared the diagnosis of Transorib- ates latus with that of Protoribates Berlese, 1908 and concluded that except for the reduction in the number of genital setae and the clubbed sensillus, T. latus resembles Protoribates . We think the validity of Transoribates need additional research.