Trigoniophthalmus kobani Kaplin, 2019

Kaplin, V. G., 2019, New species of bristletails of the genus Trigoniophthalmus Verhoeff, 1910 (Archaeognatha: Machilidae) from North Ossetia - Alania (Russia), Caucasian Entomological Bulletin (Caucas. entomol. bull.) 15 (1), pp. 25-34 : 25-28

Trigoniophthalmus kobani Kaplin , sp. n.

( Figs 1–15 )

Material. Holotype, ♂ (in slides): Russia, North Ossetia – Alania, Prigorodny Distr., environs of Koban settl., 42 ° 55ʹN / 44 ° 30′E, 1100 m, 29.04.2018 ( V. G. Kaplin) . Paratype: 1♀ (in slides), same data as for holotype .

Description. Body length: male 7 mm, female 7.5 mm. Body width: male and female 2.1–2.2 mm. General body color whitish. Antennal base, frons, clypeus, maxillae, mandibles, submentum, mentum, hypopharynx, thoracic sternites and coxae of all legs with purple hypodermal pigment of medium intensity. Color of scales on surface of body brownish. Antennae slightly shorter than body. Distal chains of flagellum divided into 7–9 articles in male and female. Clypeus of male with long thin bristles. Cercus approximately 0.37 (male) or 0.43 (female) body length, including about 25 articles. Apex of cercus with one spike ( Fig. 1 ). Every second articles of cerci with 2 or 3 colorless supporting macrochaetae on the distal inner side.

Compound eyes black (in ethanol). Ratio of length to width of compound eye about 1.02 in male and 1.05 in female; ratio of length of contact line to length of eye 0.52 in male and 0.48 in female. Paired ocelli submedian, pear-shaped, reddish-brown with very narrow white border, 1.8 times as wide as long in both sexes. Distance between inner margins of ocelli about 0.14 and between their outer margins 0.65–0.69 of total width of compound eyes in both sexes ( Fig. 2 ).

Apical article of maxillary palp 0.86–0.92 (male) or 1.01–1.02 (female) times as long as preceding one. Dorsal surface of 7 th, 6 th and 5 th articles of maxillary palp with 11 or 12, 12–14 and 2 or 3 hyaline spines, respectively, in both sexes. Ventral surface of 2–7 th articles of male maxillary palp with relatively numerous and long thin chaetae, on 6 th and 7 th articles such chaetae distributed more sparse ( Figs 3, 4 ). Same long thin chaetae also present on dorsal surface of 2 nd articles of male labial palp ( Fig. 5 ). Apical article of labial palp triangularly oval, 2.5 times as long as wide in both sexes. Mandibles with four distal teeth ( Figs 6, 7 ).

Fore femur and tibia of male and female widened. Fore femur of male without sensory field ( Fig. 8 ). Ratios of length to width of femur, tibia and tarsus as shown in Table 1 . Ratio of length of 3 rd tarsomere of tarsus to total length of tarsus about 0.35 in both sexes. Legs of male without long, thin bristles. Ventral surface of femora, tibiae and tarsi without spine-like setae. Middle and hind legs with coxal styli. Length of styli 0.5 mm (female) and 0.6 mm (male). Ratio of styli length to width of middle and hind coxae about 1.4–1.5 in female and 1.6–1.7 in male. Praetarsus with two claws and apically rounded cylindrical supporting projection between them. Ratio of length to width of projection about 1.6–1.7.

Posterior margin of pronotum with a deep notch ( Fig.9 ). In both sexes, uritesI andV–VII with 1+1 eversible vesicles, uritesII– IV with 2 + 2 such vesicles ( Figs 10, 11 ). In male, posterior angle of urosternites II–VII and VIII approximately 76–78° and 84°, respectively; but in female, anterior angle of urosternites II–VII about 86–89°. Ratios of lengths of styli (without apical spine) and urocoxites II–IX as shown in Table 2. Inner posterior lobes of urocoxites VII between eversible vesicles of female slightly protruding ( Fig. 11 ); ratio of length to total width of these lobes about 0.43. Thoracic tergites, urotergites I–IV, urosternites and urocoxites I–VI without macrochaetae in both sexes. Distribution of sublateral macrochaetae on urotergites V–X and spines on urocoxites VII–IX as shown in Table 3 . Urocoxites IX with 2–3 and 5–6 (male) or 2 and 4 (female) outer and inner sublateral spines, respectively ( Figs 12, 13 ).

Ovipositor slender, elongate (2.3 mm), slightly surpassing apex of styli IX ( Fig. 13 ). Anterior and posterior gonapophyses with approximately 40 and 41 divisions, respectively. One or two basal divisions of anterior gonapophyses and about 22 or 23 basal divisions of posterior gonapophyses glabrous.Apical macrochaetae of gonapophyses as long as three or four apical divisions combined. Distal divisions of anterior gonapophyses with 5–7, posterior gonapophyses with 3 or 4 setae (not counting sensory setae and apical macrochaetae) ( Figs 14, 15 ). Ovarioles with 10 large eggs.

Male genitalia with one pair of parameres on abdominal segment IX. Parameres with 1 + 6 divisions, slightly not attaining apex of penis ( Fig 12 ). Penis and parameres not attaining of apex of urocoxites IX for 4.8 of width of aedeagus of penis. Phallobasis of penis 1.6 times as long as aedeagus.

Differential diagnosis. Between species of the subgenera Trigoniocellus with 2 + 2 eversible vesicles on urites II–IV T. kobani sp. n. belongs to a group of small congeners with a body length of 7–9.5 mm, black or dark eyes, redish-brown paired ocelli, ratio of length to width of compound eye more than 1, the length of the contact line between compound eyes about 0.5–0.6 of eye length. This group includes 6 known species: T. kobani sp. n., T. tseyi sp. n., T. minor Kaplin, 2015 , T. borgustani Kaplin, 2015 , T. subalpinus Kaplin, 2017 and T. abchasicus Kaplin, 2017 . Trigoniophthalmus kobani sp. n. differs from other species of this group by the color of paired ocelli, distribution of long thin chaetae on male labial palp, by the ratio of lengths of apical article and preceding one of maxillary palp, posterior angle of urosternites II–V, the number of outer and inner sublateral macrochaetae on urocoxites IX. The main differences between species of this group are summarized in Table 8 .

Habitats. Specimens of Trigoniophthalmus kobani sp. n. were collected in mountain forest (Quercus, Carpinus, shrubs) under stones, 1100 m above sea level.

Etymology. The new species takes its name from the type locality: Koban, North Ossetia – Alania.

Figures

Figs 1–8. Trigoniophthalmus kobani sp. n. 1–6, 8 – male, holotype; 7 – female, paratype; 1 – apex of cercus; 2 – eyes and paired ocelli; 3 – maxillary palp (1st–3rd articles); 4 – maxillary palp (4th–7th articles); 5 – labial palp; 6–7 – distal part of mandible; 8 – fore leg (part). Scale bars 0.1 mm. Рис. 1–8. Trigoniophthalmus kobani sp. n. 1–6, 8 – самец, гоΛотип; 7 – самка, паратип; 1 – вершина церки; 2 – гΛаза и парные гΛазки; 3 – нижнечеΛюстной щупик (1-й–3-й чΛеники); 4 – нижнечеΛюстной щупик (4-й–7-й чΛеники); 5 – нижнегубной щупик; 6–7 – ΑистаΛьная часть верхней чеΛюсти; 8 – переΑняя нога (часть). Масштабные Λинейки 0.1 мм.

Figs 9–15. Trigoniophthalmus kobani sp. n. 12 – male, holotype; 9–11, 13–15 – female, paratype; 9 – pronotum; 10 – urosternite and urocoxites IV; 11 – urosternite and urocoxites VII; 12 – male genitalia with urocoxite IX; 13 – ovipositor with urocoxite IX; 14 – apex of anterior gonapophysis of ovipositor; 15 – apex of posterior gonapophysis of ovipositor.Scale bars 0.1 mm. Рис. 9–15. Trigoniophthalmus kobani sp. n. 12 – самец, гоΛотип; 9–11, 13–15 – самка, паратип; 9 – переΑнеспинка; 10 – стернит и кокситы IV сегмента брюшка; 11 – стернит и кокситы VII сегмента брюшка; 12 – поΛовой аппарат самца с кокситом IX сегмента брюшка; 13 – яйцекΛаΑ с кокситом IX сегмента брюшка; 14 – вершина переΑней створки яйцекΛаΑа; 15 – вершина заΑней створки яйцекΛаΑа.Масштабные Λинейки 0.1 мм.