Sidorchukdispus, Khaustov & Hugo-Coetzee & Ermilov & Theron, 2019

Khaustov, Alexander A., Hugo-Coetzee, Elizabeth A., Ermilov, Sergey G. & Theron, Pieter D., 2019, A new genus and species of the family Microdispidae (Acari: Heterostigmata) associated with Trinervitermes trinervoides (Sjöstedt) (Isoptera: Termitidae) from South Africa, Zootaxa 4647 (1), pp. 104-114 : 105-107

Genus Sidorchukdispus gen. nov.

Type species: Sidorchukdispus ekaterinae sp. nov.

Description. Female. Body oval. Prodorsum not covered by tergite C. Gnathosomal capsule prognathous, subtriangular, slightly longer than wide, dorsally with two pairs of cheliceral setae (cha, chb); postpalpal setae (pp) present. Cheliceral stylets long, protruding through gnathosoma. Cheliceral levers well developed. Palpi with two pairs of dorsolateral setae (dFe, dGe), femorogenu anteriorly with oval projection. Tibial claw absent. Palpal solenidion absent; accessory setigenous structure very large, round, sucker-like. Division between palpal femorogenu and tibiotarsus not visible. Subcapitular setae m and oval pits in posterior part of subcapitulum present. Pharyngeal pumps tripartite, joined together and situated on relatively short oesophagus. Pharyngeal pump 1 (php1) small, smooth, bow-shaped, pharyngeal pump 2 (php2) large, distinctly transversely striated, subrectangular, pharyngeal pump 3 (php3) very small, vestigial. Prodorsum with one pair of simple setae (sc 2), pair of clavate trichobothria (sc 1) and elongate stigmata. No modified hysterosomal setae. Tergites C, D, EF and lateral plates with distinct scale-like sculpture. Tergite C with two pairs of setae (c 1, c 2); tergite D with one pair of setae (d) and one pair of round cupules ia; tergite EF with two pairs of setae (e, f); tergite H with two pairs of setae (h 1, h 2) and pair of round cupules ih; posterior margin of tergite H with short tongue-like process. Coxal fields I with two pairs of setae (1 a, 1 b); coxal fields II with two pairs of setae (2 a, 2 b); coxal fields III with three pairs of setae (3 a, 3 b, 3 c); coxal fields IV with three pairs of setae (4 a, 4 b, 4 c). Pseudanal segment with two pairs of setae (ps 1 and ps 3). Apodemes 1 (ap1) well developed, joined with well developed prosternal apodeme (appr), apodemes 2 absent; sejugal apodeme (apsej) well developed, thickened, joined with appr. Transverse u-shaped line situated between bases of setae 1 b. Apodemes 3 (ap3) present, joined with poststernal apodeme (appo), apodemes 4 (ap4) short, thin, apodemes 5 absent. Secondary transverse apodeme absent. Posterior margin of posterior sternal plate tripartite, anterior margin of posterior sternal plate concave. Aggenital plate with scale-like microsculpture. Anterior genital sclerite (ags) short, bell-like; posterior genital sclerite (pgs) small, oval. Ventral idiosomal setae not modified. Legs I much shorter and thinner than legs II. Tibiotarsus I cylindrical, without claw; seta s and solenidion ω 2 absent. Tarsi II and III very short, with a pair of padded claws and very large flipper-like, distally striated empodium; tarsus IV with a pair of small simple claws and a small flipper-like empodium. Pretarsus IV very short. Setae u’ on tarsi II and III absent. Seta v” of femur II very short. Solenidion on tibia IV absent. Tarsus III with well developed solenidion. Femora III and IV each divided into basi- and telofemur. Leg setation: leg I; Tr 1 (v’), Fe 3 (d, l’, v”), Ge 4 (l’, l”, v’, v”), Tita 15(3) (d, l’, l”, v’, v”, k, tc’, tc”, ft’, ft”, p”, pl’, pl”, pv’, pv”, ω 1, φ 1, φ 2); leg II: Tr 1 (v’), Fe 3 (d, l’, v”), Ge 3 (l’, l”, v’), Ti 4(1) (d, l’, v’, v”, φ), Ta 5(1) (tc’, tc”, pl”, pv’, pv”, ω); leg III: Tr 1 (v’), Fe 2 (d, v’), Ge 2 (l’, v’), Ti 4(1) (d, l’, v’, v”, φ), Ta 5(1) (tc’, tc”, pl”, pv’, pv”, ω); leg IV: Tr 1 (v’), Fe 2 (d, v’), Ge 1 (v’), Ti 4 (d, l’, v’, v”), Ta 6 (tc’, tc”, pl”, pv’, pv”, u’).

Male and larva unknown.

Differential diagnosis. With regard to the absence of a tarsal claw on tibiotarsus I, tripartite posterior margin of posterior sternal plate, short tarsi II and III with padded claws and large flipper-like empodium, very short legs I, similar shape of pharyngeal pumps, presence of sclerotized lines on tergites C, D, EF and aggenital plate, and very short seta v” on femur II, the new genus is most similar to Ethiodispus Khaustov, 2017. Females of Sidorchukdispus gen. nov. differ from Ethiodispus by the presence of trichobothria (absent in Ethiodispus), presence of setae chb on gnathosoma (absent in Ethiodispus), presence of setae l” on genu I (absent in Ethiodispus), absence of setae u’ on tarsi II and III (present in Ethiodispus), very long cheliceral stylets protruding through gnathosomal capsule (short stylets not protruding through gnathosomal capsule in Ethiodispus), and unusually large sucker-like accessory setigenous structure (small in Ethiodispus).

Etymology. The new genus is named after the well accomplished Russian acarologist, Dr Ekaterina Sidorchuk (Paleontological Institute, Russian Academy of Sciences), who passed away so early in her life.

Species included. The genus Sidorchukdispus gen. nov. includes only one species, S. ekaterinae sp. nov. Distribution and habitat. Sidorchukdispus ekaterinae sp. nov. inhabits nests of the termite, Trinervitermes trinervoides in South Africa.