Formicomotes brasiliensis Khaustov & Frolov 2018, sp. nov.

Formicomotes brasiliensis sp. nov.

(Figs 1–3)

Description. Phoretic female (Figs 1–3). Body weakly sclerotized. Length of idiosoma 105 (105), maximum width 64 (62–64). Gnathosoma (Figs 1, 2). Length of gnathosoma 15 (15–17), width 18 (17–19). Cheliceral stylets small, thin, directed ventrally. Seta dFe short, smooth, blunt-ended; seta dGe more than 5 times longer than dFe, pointed, smooth. Subcapitular seta m 12 (12–14) smooth, pointed. Palpal solenidion weakly clavate. Pharynx thin-walled, with three lateral projections.

Idiosomal dorsum (Fig 1A). All dorsal shields smooth. A pair of subcuticular dimples located just posteriad setae v 2. All dorsal setae smooth. Setae f blunt-ended, other dorsal setae pointed. Posterior margins of prodorsal shield and tergites C and D dentate. Cupules ia distinctly larger than im. Tergite C with three porous areas laterad setae c 1; tergite D with one porous area mediad cupules im. Lengths of dorsal setae: v 1 15 (15–16), v 2 17 (17–18), sc 2 14 (12–15), c 1 8 (8–10), c 2 15 (13–15), d 13 (13–14), e 13 (13–14), f 6 (5–6), h 1 vestigial, h 2 51 (49–53). Distances between setae: v 1 –v 1 21 (19–21), v 2 –v 2 22 (22–23), sc 2 –sc 2 45 (43–46), c 1– c 1 19 (19–21), d–d 51 (51–54), e–e 24 (24–25), f–f 9 (9–10), e–f 9 (7–9), h 1– h 1 5 (5), h 2– h 2 10 (10–11).

Idiosomal venter (Fig 1B). All ventral plates smooth. All ventral setae smooth, blunt-ended. Apodemes 1 and 2 (ap1, ap2) well developed. Ap1 joined with short prosternal (appr) apodeme. Apodemes 3 (ap3) well developed.

Weak linear depressions visible between coxal fields I and II, III and IV, and between coxal fields IV. Posteromedian corners of coxal fields II with large triangular projections. Soft, striated cuticle located between anterior and posterior sternal plates and between posterior sternal plate and plate HPsAg. Plate HPsAg with a pair of large sucker-like structures. Lengths of ventral setae: 1 a 5 (5), 2 a 8 (7–8), 3 a 4 (5–6), 4 a 5 (5–6), ag 4 (4).

Legs (Fig 2). All legs subequal in length. All legs setae smooth, setae pl” and pv” on tarsi II-IV distinctly spine-like and blunt-ended. Leg I (Fig 2A). Tarsus with two symmetrical claws and semi-oval empodium. Eupathidium k flattened, lanceolate. Setae (u), tc” on tarsus and v” on tibia pointed. Other leg setae blunt-ended. Lengths of solenidia ω 1 3 (3), ω 2 1 (1), φ 1 4 (4), φ 2 2 (2); solenidion ω 1 striated, other solenidia non-striated. Leg II (Fig 2B). Solenidion ω 3 (3), solenidion φ 2 (2), both striated. Setae tc”, pv’ on tarsus and v” on tibia pointed. Other leg setae blunt-ended. Leg III (Fig 2C). Solenidion φ 2 (2) striated. Setae tc’, tc”, pv’ on tarsus and v” on tibia pointed. Other leg setae blunt-ended. Leg IV (Fig 2D). Solenidion φ 2 (2) striated. Setae tc”, pv’ on tarsus and v” on tibia pointed. Other leg setae blunt-ended.

Male and non-phoretic female unknown.

Type material. Female holotype, slide No. 10718, Brazil, Mato Grosso, Mutuca River, 15°18'27"S, 55°58'10"W, May 2017, A.V. Frolov leg., on Nasutitermes sp. The mites were attached to the ventral surface of the head of termite workers; paratypes: 5 females, same data.

Type deposition. The holotype and one paratype are deposited in the collection of UNESP—Universidade Estadual Paulista, Department of Zoology and Botany, 15054–000 São José do Rio Preto – SP, Brazil; two paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia; two paratypes are deposited in the collection of the Zoological Institute of RAS, Saint Petersburg, Russia.

Differential diagnosis. The new species is very similar to the phoretic female of F. heteromorphus, but differs by having blunt-ended setae f (vs. pointed in F. heteromorphus), by setae c 1 distinctly shorter than c 2 (vs. c 1 and c 2 subequal in F. heteromorphus), by setae f distinctly shorter than e (vs. setae e and f subequal in F. heteromorphus), by subequal setae dGe of palp and subcapitular setae m (vs. dGe distinctly longer than m in F. heteromorphus), and by setae d and e subequal (vs. d distinctly longer than e in F. heteromorphus).

Etymology. The name of the new species refers to its distribution in Brazil.

Remarks on phoresy. All available specimens were collected only on workers, in the “pocket” formed by the ventral surface of the termite’s head and the fold of soft cuticle adjacent to the head (Fig. 3). In all cases, we found only one phoretic female of F. braziliensis per one termite. Examination of soldiers did not reveal phoretic mites on them, probably because they have no such “pocket” on ventral surface of the head.