Makwacarus, Stekolnikov, 2018

Stekolnikov, Alexandr A., 2018, African chiggers (Acariformes: Trombiculidae) in the collection of Alex Fain, with a description of a new genus and three new species, Acarologia 58 (2), pp. 265-286 : 274-275

Makwacarus n. gen.

Zoobank: ED846F2D-8D28-400F-BFDF-F9F87D05D950

Diagnosis — SIF = 6B-B-3-2111.0000; fsp = 7.7.7; fCx = 1.1.1; fSt = 2.2; fPp = B/B/BBB; fSc: AL>= PL ≫ AM. Cheliceral blade with tricuspid cap; galeal setae branched; palpal claw with 3 prongs; palpal femoral, genual, and tibial setae branched; palpal tarsus with 6 branched setae and basal tarsala. Scutum nearly pentagonal, wider than long, with broadly rounded posterior margin, bearing 1 anteromedian, 2 anterolateral and 2 posterolateral scutal setae; anterolateral scutal setae longest; sensilla globose, sensillary bases posterior to level of PLs; eyes 2 + 2. Legs 7-segmented, with 1 pair of claws and claw-like empodium; tibialae II situated in distal half of segment, not in tandem; mastisetae absent.

Type species — Makwacarus petrodromi n. sp.

Host — four-toed elephant shrew ( Macroscelidea : Macroscelididae : Petrodromus tetradactylus ).

Etymology — The name of the new genus is combined from the name of type locality (Makwa) and the new Latin word acarus meaning “mite”.

Differential diagnosis — By the shape of scutum with broadly rounded, protruded margin, globose sensilla, and by the relation between lengths of scutal setae (AL>= ≫ PL AM), the new genus is similar to Helenicula Audy, 1954 , Schoengastia Oudemans, 1910 , some species of Herpetacarus (Abonnencia) Vercammen-Grandjean, 1960 , and some species of Guntheria (Phyllacarus) Vercammen-Grandjean, 1967 , first of all, Guntheria innisfailensis (Womersley et Heaslip, 1943) from Australia. The position of tibialae II in distal half of segment and not in tandem is one more trait common for the new genus, Helenicula , and Schoengastia equina Vercammen-Grandjean, 1971 . The relation of lengths of leg tarsalae with tarsala II longer than tarsala I and the position of tarsala I distal to microtarsala are also characteristic for the new genus and for Helenicula ( Nadchatram & Traub 1971) .

The new genus, however, differs from Helenicula in the presence of six setae on palpal tarsus vs. 4-5 and in the sensillary bases situated far apart (distance between sensillary bases is roughly equal to the distance between a sensillary base and a base of posterolateral seta) vs. situated close together (with the gap being less than the diameter of either base). The new genus differs from Schoengastia in having cheliceral blade with usual tricuspid cap only, without longitudinal row of teeth, in the palpal tarsus 6B vs. 7BS, and in having branched galeal setae vs. always nude. The new genus differs from Herpetacarus (Abonnencia) in having palpal tarsus 6B vs. 7B, galeal setae branched vs. nude and scutum not telostigmal (sensillary bases are not significantly closer to the bases of posterolateral setae than to each other). The new genus differs from a very speciose and heterogeneous subgenus Guntheria (Phyllacarus) in the palpal tarsus 6B vs. 5B ( Domrow & Lester 1985).