Turquimachilis taurica, Kaplin, 2021

Kaplin, V. G., 2021, A new species of bristletails of the genus Turquimachilis (Microcoryphia: Machilidae) from the Crimea, Zoosystematica Rossica (Zoosyst. Rossica) 30 (1), pp. 40-45 : 41-45

Turquimachilis taurica sp. nov.

( Figs 1–14 )

Holotype. Female (slide-mounted); Republic of Crimea, Grand Canyon of Crimea, 44°31 ′ 40 ″ N, 34°01 ′ 00 ″ E, 500–600 m, under stones, 7.IX.2020, V. Kaplin leg.

Description. Body length: 9.6 mm; body width: 2.0 mm; length of antenna: about 7.5 mm; length of cerci: 3.4 mm; total width of eyes: 1.00 mm; length of eye: 0.44 mm; width of paired ocellus: 0.36 mm; length of paired ocellus: about 0.13 mm; length of coxal styli of legs: about 0.4 mm; length of ovipositor: 1.45 mm.

General body colour (in ethanol) light brownish, with dark brown scales on upper and lower sides of body. Frons, clypeus, occiput, mandibles, maxillae, maxillary and labial palps, and legs with reddish brown or reddish violet pigment. Head, maxillary palps and coxae most pigmented. Scapus, pedicellus and flagellum of antennae without pigment.

Antennae shorter than body. Distal chains of flagellum divided into 9–11 annuli ( Fig. 1 ). Cercus approximately 0.36 times the body length. Apex of cercus ( Fig. 2 ) with two lateral spikes. Articles of cerci, except for apical two, with colourless supporting macrochaetae on inner side.

Compound eyes dark brown (in ethanol). Ratio of compound eye length to its width 0.89; ratio of contact line length to eye length 0.61 ( Fig. 3 ). Paired ocelli black with narrow white rim, shoeshaped, subinferior to compound eyes. Frons slightly swollen between paired ocelli. Distance between inner margins of ocelli about 0.21 times and between their outer margins 0.92 times the total width of compound eyes.

Maxillary palp ( Fig. 4 ): apical palpomere 0.84 times as long as preceding one; ratio of lengths of 5th and 4th palpomeres about 1.64; dorsal surface of 7th, 6th and 5th palpomeres with 17–18, 16–18 and 5–6 hyaline spines, respectively. Labial palp ( Fig. 5 ): apical palpomere triangular oval, 2.1–2.2 times as long as wide, with about 21–25 sensorial cones. Mandible with four well-developed distal teeth ( Fig. 6 ).

Fore and middle femur and tibia widened ( Fig. 7 ). Fore and hind legs 1.09 and 1.16 times as long as middle legs, respectively. Ratios of length to width of femur, tibia and tarsus as in Table 1 . Ratio of length of 3rd tarsomere of hind tarsus to its total length about 0.39. Ventral surfaces of coxae, femora, tibiae and tarsi without hyaline spine-like chaetae. Ratio of coxal stylus length to width of middle and hind coxa about 1.7 ( Fig. 8 ).

Urocoxites I and VI–VII with 1 + 1 eversible vesicles; urocoxites II–V with 2 + 2 eversible vesicles. Posterior angle of urosternites II–VI approximately 82–86°, that of urosternite VII about 74°. Ratios of lengths of urosternites and urocoxites II–VI 0.67–0.69. Ratios of lengths of urostyli (without apical spine) and urocoxites II–VII 0.50–0.54. Ratio of length of urostylus and urocoxite VIII 0.68, IX 0.45. Ratios of lengths of apical spines and urostyli II–VIII 0.55–0.62 ( Figs 9–11 ). Urocoxite VII ( Fig. 10 ) with well-developed lobes protruding between styli; ratio of length to width of one lobe about 0.75. Thoracic tergites, urosternites, urocoxites I–VIII, and urotergites I–VI and X without macrochaetae. Urocoxites IX ( Fig. 12 ) with 3–5 inner sublateral spines (spiniform chaetae), without outer sublateral spines. Urotergites VII with 1 + 1, urotergites VIII and IX with 2 + 2 sublateral spines.

Ovipositor weakly sclerotised, thickened, covered by urocoxites IX, stout, similar to that of T. mendesi .

Gonapophysis VIII ( Fig. 13 ) with 17 divisions; its apex with two small spine-like lobules and a subterminal chaeta between them; chaeta being a little longer than apical division; apical division with about 15 sensory spines and 2–3 relatively long thin chaetae in preapical part and with two curved chaetae in basal part. Remaining divisions of gonapophysis VIII with a row of setae, some of which, mainly those on inner and outer sides of gonapophysis, long and ciliary. Basal division without chaetae. Gonapophysis VIII without digging teeth.

Gonapophysis IX ( Fig. 14 ) with 19 divisions, a somewhat curved horn at apex and a subterminal chaeta being slightly longer than apical division. Apical division also with a group of 11–12 tiny sensory spines; these spines present also on preceding 5–6 divisions, but number of spines decreasing towards base. Each of these divisions also with about 2–4 chaetae; chaetae on outer side longer. Basal division without chaetae.

Comparison. According to the structure of the female gonapophyses and 2 + 2 eversible vesicles on urocoxites II–V, the new species belongs to the genus Turquimachilis (Bach de Roca et al., 2013) , which was monotypic, with the only species T. mendesi . The main morphological differences between T. taurica sp.nov. and T. mendesi are given in Table 2 . The new species differs from T. mendesi in the structure of the compound eyes, maxillary palp, urocoxites, and the number of divisions of gonapophyses. The ratio of lengths of contact line and compound eye in female of T. taurica sp. nov. is about 0.6, while in female of T. mendesi it is about 0.5. The numbers of hyaline spines on the dorsal surface of the 6th and 7th palpomeres of maxillary palps are 16–18 and 9–12, respectively. The ratios of length to width of hind tibia are about 2.8 and about 2.6, respectively; the ratios of lengths of urostyli and urocoxites II–V are 0.50–0.52 and 0.38–0.43; the number of divisions of gonapophyses are 17–19 and 15–16, respectively. The urocoxites of T. mendesi have no spiniform chaetae, whereas urocoxites IX of T. taurica sp. nov. bear 3–5 inner sublateral spines.

Etymology. The species name is a Latin adjective referring to Chersonesus Taurica, an ancient name of the Crimea, where the holotype was collected.

Habitat. The holotype of T. taurica sp. nov. was collected in a forest ( Carpinus , Fagus , Fraxinus excelsior , Quercus robur ) among the stones.

Figures

Figs 1–8. Turquimachilis taurica sp. nov., holotype (female). 1, distal chain of flagellum; 2, apex of cercus; 3, compound eyes and paired ocelli; 4, maxillary palp; 5, labial palp; 6, apex of mandible; 7, fore leg; 8, hind leg (coxa and a part of trochanter). Scale bars: 0.1 mm.

Figs 9–14. Turquimachilis taurica sp. nov., holotype (female). 9, urosternite and urocoxite V; 10, urosternite and urocoxite VII; 11, urocoxite VIII; 12, urocoxite IX; 13, gonapophysis VIII; 14, gonapophysis IX. Scale bars: 0.1 mm.