Oconnoricheylus, Bochkov & Otto, 2010

Bochkov, Andre V. & Otto, Jurgen C., 2010, Five new species of predaceous cheyletid mites (Acari: Prostigmata: Cheyletidae), Zootaxa 2727, pp. 1-20 : 2-3

Genus Oconnoricheylus gen. nov.

Type species: Oconnoricheylus speciosus Bochkov and Otto sp. nov., by original designation

Diagnosis. FEMALE. Gnathosoma. Palpal femur covered by small tubercles dorsally, with 3 setae, fan-like dF and filiform v’ and v”, palpal genu with 2 fan-like setae, dG and l”G; palpal tibia with 3 setae, fan-like dTi and l”Ti, filiform l’Ti; palpal tarsus with short solenidion ω 1 and 4 eupathidia, comb-like acm and sul, filiform and slightly serrate in apical part ul’, and very short, stick-like ul”. Palpal claw with several projections. Peritremes arch-like, with few segments. Rostral shield (tegmen) distinctly ornamented, its lateral margins without projections; rostrum (protegmen) without distinct ornamentation. Idiosoma. Propodonotal and hysteronotal shield present, ornamented and covering most part of dorsal idiosomal surface. Striated cuticle without tubercles. Eyes present, situated at lateral margins of propodonotal shield between bases of setae ve and si. Full set of idiosomal setae present: vi, ve, si, se, c1, c2, d1, d2, e1, e2, f1, f2, h1, h2, ps1 —situated dorsally, fan-like; ps2, ps3, g1, g2, ag1, ag2, and ag3 —situated ventrally, filiform; additionally dorsal shields bearing several median neotrichial fan-like setae. Legs. Legs not thickened, about 2/3 length of idiosoma. Tarsi of all legs distinctly developed, at least twice as long as respective tibiae, bearing pretarsi with multirayed empodium and pair of subequal claws with or without basal angles. Tarsus I with 10 setae, tc’, tc”, a”, u’, u” —smooth filiform, p’, p”, vs —serrate filiform, ft —widely lanceolate; solenidion ω 1 situated far anterior of guard seta ft, closer to tarsal apex. Tarsus II with 7 setae, tc’, tc” —smooth filiform, p’, p”, u’, u”, vs —serrate filiform, and solenidion ω 1 situated ventrally in median part of segment. Tarsi III and IV with same setation as tarsi II but without solenidion. Most setae on other articulated segments of legs widely lanceolate or fan-like. Tibia I with 4 setae, d, l’, v’, v” and solenidion φ; tibiae II–IV with 4 setae each, without solenidion. Genu I with 2 setae, d and l’, and solenidion σ, genua II–IV with 2 setae each. Femora I–III with 2 setae, d and v, femur IV with 1 seta, d. Trochanters I, II, and IV with 1 seta (v) each, trochanter III with 2 setae, v and l’. Coxae I, III, and IV with 3 setae each, 1a, 1b, and 1c, 3a, 3b, and 3c, 4a, 4b, and 4c, respectively; coxa II with 1 seta, 2b; all coxal setae filiform, excluding lanceolate 3b.

MALE. Generally similar to female. Propodonotal shield bearing only few pairs of neotrichial setae, hysteronotal shield without neotrichial setae. Solenidion ω 1 of tarsi I situated close to guard seta ft, solenidion ω 1 of tarsi II situated laterally, and tarsi III and IV bearing distinct ventral solenidion ω 1 in basal part.

Species included. Oconnoricheylus speciosus sp. nov., O. chimaera ( Bochkov & Ochoa, 2005) comb. nov. (transferred from Alliea Yunker ).

Etymology. This genus is dedicated to the well-known American acarologist Prof. Barry M. OConnor (Museum of Zoology, University of Michigan, Ann Arbor, USA).

Remarks. Oconnoricheylus gen. nov. belongs to the generic group with unclear phylogenetic relationships whose females possess a subapically located solenidion ω 1 on tarsus I ( Bochkov & Fain 2001). This generic group includes the genera Alliea Yunker and Caudacheles Gerson. The genus Chiapacheylus De Leon , whose females also have solenidion ω 1 situated close to the subapical position probably also belongs to this group.

The new genus differs from Alliea in both sexes by the presence of eyes and four setae on tibia II (vs. five setae in Alliea ). Unfortunately, in Alliea , the gnathosomal structure is known only for males, whereas the gnathosoma of a single female specimen known in this genus ( Alliea laruei Yunker, 1960 ) is lost. Therefore only leg and idiosomal characters can be compared here for females of both genera. Meanwhile it is clear from the structure of the male gnathosoma that the gnathosomal characters are especially important for the differentiation of Oconnoricheylus and Alliea . In males of Oconnoricheylus , the palpal claws possess elongated projections, eupathidium ul ’ is slightly serrate apically and eupathidia acm and sul are comb-like. In males of Alliea , the projections of the palpal claws are absent, eupathidium ul ’ is smooth, eupathidium acm is spatulate or spine like, and eupathidium sul is inflated.

Oconnoricheylus differs from Caudacheles in females (males of this genus are unknown), by the comb-like eupathidium acm, the presence of distinct teeth on the palpal claws, fan-like setae d and l” of the palpal tibia, eyes, and by the absence of the caudal disc. In females of Caudacheles , eupathidium acm is smooth, palpal claws are without teeth, setae d and l” of the palpal tibia are thickened filiform, eyes are absent, and the caudal disc is present.

Finally, Oconnoricheylus differs from Chiapacheylus in females (males of this genus are unknown) by the presence of distinct teeth on the palpal claws, filiform seta v ’ of palpal femur, and by the glabrous setae ps2 and ps3. In females of Chiapacheylus , the palpal claws are without teeth, seta v ’ of palpal femur is widely lanceolate, and setae ps2 and ps3 are bifid.