New Oribatid Mites of the Superfamily Ceratozetoidea (Acari: Oribatida) from Ethiopia

ABSTRACT Four new species of oribatid mites of the superfamily Ceratozetoidea, Ceratozetes baleensis sp. n. (Ceratozetidae), Ocesobates schatzi sp. n. (Chamobatidae), Africoribates subiasi sp. n. and A. amorphus sp. n. (both Humerobatidae), are described from southern Ethiopia. The first two species were collected in soil from Harenna Forest of Bale Mountains National Park (the second species was also collected in plants on rock from Cholomu Forest, 10 km to the south of Ginchi city); the third and fourth species were collected in litter (Cholomu Forest) and plants (Bale Mountains National Park, plateau Sanetti). The genus Ocesobates is recorded for the first time in Africa. The genus Africoribates is recorded for the first time in Ethiopia. Identification keys to all known species of Ocesobates and Africoribates are presented.

In the course of faunistic studies of the oribatid fauna of the southern part of Ethiopia in 2009-2010, we found representatives of four new species of the superfamily Ceratozetoidea, belonging to the genera Ceratozetes Berlese, 1908, Ocesobates Aoki, 1965 and Africoribates Evans, 1953. Ceratozetes is a large genus of the family Ceratozetidae that was proposed by Berlese (1908) with Oribata gracilis Michael, 1884 as type species. Currently, it comprises 60 species that collectively have a cosmopolitan distribution (Subías 2004(Subías , online version 2011. Previously only three species of Ceratozetes were recorded from Africa: C. insignis Balogh, 1966 from Cameroon, C. problematicus Mahunka, 1982from Ethiopia, C. rostroserratus Wallwork, 1965 from Chad and Congo. The diagnostic characters of the genus Ceratozetes are (see also Behan-Pelletier & Eamer 2009): pteromorphs of notogastral setae; rostrum without (occasionally with) small lateral teeth, with or without medial tooth, or with medial indentation; custodium with free distal point.
Ocesobates is a small genus of the family Chamobatidae that was proposed by Aoki (1965) with Ocesobates kumadai Aoki, 1965 as type species. Currently, it comprises three species that are collectively distributed in Europe and Japan (Subías 2004(Subías , online version 2011: O. boedvarssoni (Sellnick, 1974) from Europe, O. bregetovae Shaldybina, 1974 from the southern Palearctic region, O. kumadai Aoki, 1965 from Japan. This genus has not previously been recorded in Africa. The diagnostic characters of the genus Ocesobates are (see also Aoki 1965;Shaldybina 1969;Sellnick 1974;Gjelstrup 1978): lamellae with short, truncate cusp, bearing lamellar seta; rostrum U-shaped (one exception: rostrum of O. kumadai with medial anterior point).
The new species are described below as Ceratozetes baleensis sp. n., Ocesobates schatzi sp. n., Africoribates subiasi sp. n. and A. amorphus all known species of Ocesobates and Africoribates are presented.

MATERIAL AND METHODS
The specimens were studied in lactic acid, mounted on temporary cavity slides for the duration of the study, then were stored in 70 % alcohol in vials. All body measurements are presented in micrometres. The body length was measured in lateral view, from the tip of the rostrum to the posterior edge of the ventral plate, to avoid discrepancies caused by different degrees of notogastral distension. The notogastral width refers to the maximum width in dorsal aspect. The length of body setae was measured in lateral aspect.
Austroceratobates is a monotypical genus of the family Ceratozetidae that was proposed by Mahunka (1985) with Austroceratobates endroedyi Mahunka, 1985 as type species. It differs from other genera of family by the shape of tutoria (long, narrow, without cusps) (Mahunka 1985). In our opinion, only the shape of tutoria cannot be used for the separation of Austroceratobates from the other genera, therefore most likely this genus should be considered as a synonym of Ceratozetes. In turn, Austroceratobates is similar morphologically to the genus Limnozetella Willmann, 1931 (Limnozetidae) with the single (type) species Limnozetella lamellata Willmann, 1931. We do not discuss placing Austroceratobates in Ceratozetidae and the taxonomic relations between Ceratozetes, Austroceratobates and Limnozetella herein, because it should be addressed by separate research.

Etymology:
Ocesobates  Lateral part of body torium long, thin, weakly dilated in median part, with thin and smooth cusp distally.
im visible in dorsal view; ia, ih and ips visible in la-teral view; ip visible in posterior view. Opisthonotal gland opening located laterally to seta h 3 .
In having the combination of a granulate body surface, presence of notogastral setae and areae porosae, A. subiasi sp. n. is similar to A. ornatus Evans, 1953from Tanzania (Evans 1953Mahunka 1984a); however, it differs from the latter by having larger body size (531-564 × 348-381 in the new species; 429-454 × 295-324 in A. ornatus) and long interlamellar setae, as long as lamellae (obviously shorter than lamellae in A. ornatus).
In having the combination of the morphology of lamellae and translamella, granulate body surface and presence of areae porosae, A. subiasi sp. n. also is similar to A. evansi Balogh, 1959 from Angola andCongo (Balogh 1959a). The problem in the comparative analysis, however, is that the length and structure of interlamellar setae is unknown in A. evansi. Balogh (1959a) wrote that the interlamellar setae are broken in the specimen available to him for study. However, A. subiasi sp. n. can be differentiated from A. evansi by having larger body size (531-564 × 348-381 in the new species; 415-420 TABLE 1 Leg setation and solenidia of Ceratozetes baleensis sp. n., Ocesobates schatzi sp. n., Africoribates subiasi sp. n. and A. amorphus sp. n. Roman letters refer to normal setae (e -famulus), Greek letters refer to solenidia. One apostrophe (') marks setae on anterior, double apostrophe (") setae on posterior side of the given leg segment. Parentheses refer to a pair of setae. * -Seta present only in C. baleensis sp. n.