Matiesacarus Stekolnikov, 2025

Genus Matiesacarus Stekolnikov , gen. nov.

Type species: Matiesaсarus capensis sp. nov., designated here.

Diagnosis. SIF = 7B, 6B1N-B-3-(2–3)111.(2–5)(1–3)00; fPp = B/B/BNB; fCx = 1.1.1; fSt = 2.2; fsp = 7.7.7; fD = 2H-8(7)-6-6(4)-2(4)+(4–8). Eyes 2 + 2, on ocular plate; NDV = 50–64. Scutum with sparse puncta of different size, pentagonal or trapezoidal; bases of sensilla (trichobothria) situated anterior to level of PLs; sensilla flagelliform, covered with short cilia in proximal half and numerous long branches in distal half. Cheliceral blade with tricuspid cap; galeal (deutorostral) setae branched; palpal claw (odontus) three-pronged; palpal tarsus with seven branched (or six branched and one nude) setae and tarsala. Legs seven-segmented (with divided femur), rather short (Ip = 700–764); onychotriches absent; parasubterminala I ( z) nude; 2 or 3 genualae I ( σ). Unspecialized setae (leg I, II, III): coxa 1, 1, 1; trochanter 1, 1, 1; basifemur 1, 2, 2; telofemur 5, 4, 3; genu 4, 3, 3; tibia 8, 6, 6 (including one to three nude mastitibialae); tarsus 22, 16, 14(16) (including two to five nude mastitarsalae).

Etymology. The name of the new genus is combined from “Maties”, the nickname of Stellenbosch University students, and the word acarus meaning “mite”.

Included species: Matiesacarus capensis Stekolnikov , sp. nov., M. elegantissimus ( Kolebinova, 1981) , comb. nov.

Remarks. The new genus is similar to the genera Pentidionis Vercammen-Grandjean and Loomis, 1967 and Hexidionis Vercammen-Grandjean and Loomis, 1967 by the shape of scutum, shape of sensilla (having multiple long branches in distal half and short cilia in proximal half—the latter is a characteristic of Hexidionis ), and by the sculpture of scutum (presence of sparse large puncta over its surface and small, more dense puncta in some parts of it). However, Matiesacarus gen. nov. differs from both of them in the absence of onychotriches, in having short legs without additional bars (internal sclerotized rings), and tibialae II arranged in tandem vs. grouped in apical part of the segment. In addition, the new genus differs from Pentidionis in the eyes situated on the ocular plates vs. separated from each other and from Hexidionis in the absence of palpal subterminala ( ζ) ( Vercammen-Grandjean & Loomis 1967; Lucas & Loomis 1968). Stekolnikov (2018) included the presence of palpal subterminala in the diagnosis of Pentidionis by mistake.

Neotrombicula ( Neotrombiculoides) elegantissima Kolebinova, 1981 was described from an elephant shrew Galegeeska rufescens (Peters, 1878) (syn. Elephantulus rufescens ) from Tanzania ( Kolebinova 1981). The genus Neotrombiculoides Vercammen-Grandjean, 1960 , later considered as a subgenus of Neotrombicula Hirst, 1925 by Vercammen-Grandjean & Langston (1976), is an artificial group of Neotrombicula -like chiggers characterized by the presence of seven unspecialized setae on palpal tarsus and the absence of palpal subterminala. Some other species of Neotrombiculoides can probably be transferred to different genera in the future. Neotrombiculoides claviglicola (Lawrence, 1949) , the type species of this taxon, clearly differs from both species of Matiesacarus gen. nov. by the shape and sculpture of scutum (covered with dense small puncta, with its posterior margin greatly projected and rounded at edges), shape of sensilla (without dense short cilia in proximal half), presence of only one mastitarsala vs. 2–5 mastitarsalae and 1–3 mastitibialae, nude galeala and setae on palpal femur and genu vs. branched, and by the shape of PLs and dorsal idiosomal setae—thick and covered with very strong spike-like barbs vs. thin and covered with small barbs, similar to AM and ALs.