Troxodania Khaustov and Trach

Khaustov, Alexandr A. & Trach, Viacheslav A., 2014, Mites of the superfamily Pygmephoroidea (Acari: Heterostigmata: Neopygmephoridae, Pygmephoridae) associated with Trox cadaverinus (Coleoptera: Trogidae) from the Far East of Russia, with description of a new genus and two new species, Zootaxa 3754 (1) : -

Genus Troxodania Khaustov and Trach gen. nov.

Type species: Pygmephorus decumanus Krczal, 1959 , designated here

Description. FEMALE. Gnathosomal capsule slightly longer than wide. Dorsal gnathosoma with 2 pairs of cheliceral setae (cha and chb). Postpalpal setae absent. Dorsal medial apodeme indistinct. Ventral gnathosoma with 1 pair of setae m. Palps short, with setae dFe and dGe dorsolaterally, 1 small solenidion and accessory setigenous structure ventrally, and terminated with small claw. Pharyngeal pump 2 about 1.5 times longer than pharyngeal pump 3.

Idiosomal dorsum. Prodorsum with 2 pairs of setae (v 2, sc 2), 1 pair of capitate trichobothria (sc 1) and 1 pair of oval stigmata. Anterior margin of tergite С covers posterior part of prodorsum. Two pairs of cupules (ia, ih) present on tergites D and H respectively. Tergites C and D with 1 pair, tergite EF with 2 pairs of small pore-like structures. Dorsal idiosomal setae usually long and distinctly barbed.

Idiosomal venter. Coxal fields I and II with 2 pairs of setae each. Apodemes 2 (ap2) well developed, joined with presternal apodemes (appr). Apodemes 3 (ap3) usually long and variable in sclerotization extent, apodemes 4 (ap4) variable in length. Apodemes 5 (ap5) absent. Posterior margin of posterior sternal plate entire, usually slightly convex. Three pairs of subequal pseudanal setae (ps 1– ps 3) present. Anterior and posterior genital sclerites very small, median genital sclerite present, well developed.

Legs. Leg I. Tibiotarsus of leg I distinctly thickened, with well developed pinnaculum bearing eupathidion tc”. Tarsal claw very large, with median process. Modified setae u’ and u” form large structure opposing to claw. Solenidion ω 1 prominent, its lateral margin not joined with tibiotarsus. Setae k long, barbed, not eupathidium-like. Setae dFeI hook-like. Setal formula: Tr 1–Fe3–Ge4–TiTa16(4). Leg II. Setal formula: Tr 1–Fe3–Ge3–Ti4(1)– Ta6(1). Tarsus with thickened basally claws. Modified setae absent. Leg III. Setal formula: Tr 1–Fe2–Ge2–Ti4(1)– Ta6. Claws as on leg II. Leg IV. Setal formula: Tr 1–Fe2–Ge1–Ti4(1)–Ta6. Claws well developed, simple, empodium large. Tarsus IV not extremely long, with short pretarsus.

MALE and LARVA unknown.

Diagnosis. By the presence of the median genital sclerite in females, the new genus similar to the genera Petalomium Cross, 1965 , Acinogaster Cross, 1965 and Pseudopygmephorus Cross, 1965 . The new genus is most similar to the genus Pseudopygmephorus but differs by solenidion ω 1 prominent (vs. not prominent, fused with tibiotarsus by its lateral margin in Pseudopygmephorus ), tibiotarsus I greatly enlarged (vs. usually not enlarged in Pseudopygmephorus ), the posterior genital sclerite small, oval, with clear anterior margin (vs. posterior genital sclerite distinctly elongate, with indistinct anterior margin).

Species included. The new genus includes at least 5 species: Troxodania decumanus ( Krczal, 1959) comb. nov., T. sinanii ( Sevastianov and Zahida Al Douri, 1989) comb. nov. (transferred from Bakerdania ), T. troxi ( Mahunka and Philips, 1978) comb. nov. (transferred from Sicilipes ), T. fengxiannis (Gao and Zou, 1992) comb. nov. (transferred from Sicilipes ) and T. magnifica Khaustov and Trach sp. nov.

Distribution and habitat. Mites of the genus Troxodania are distributed worldwide, most of them phoretic on different trogid beetles ( Coleoptera : Trogidae ) ( Philips 2009).

Etymology. The generic name derived from the name of troxid beetle, typical phoretic hosts of Troxodania mites.