Charimachilis taurica Kaplin, 2021

Kaplin, V. G., 2021, A new species of bristletails of the genus Charimachilis (Microcoryphia: Machilidae) from Crimea, Russian Entomological Journal 30 (2), pp. 123-128 : 125-127

Charimachilis taurica Kaplin , sp.n.

Figs 1–11 .

MATERIAL. Holotype, ♀ Republic of Crimea, vicinity of the city Staryi Krim leg. V. Kaplin 13. IX.2020, mixed forest ( Carpinus, Fagus , Fraxinus excelsior , Quercus robur ), under stones, 350 m, 45°01´N, 35°05´E ( VIZR).

DESCRIPTION (holotype). Body length 10.0 mm, width 2.6 mm; total eyes width 0.86 mm, eye length: 0.43 mm; paired ocelli width and length 0.41 and 0.18 mm, respectively; coxal styli length: 0.5–0.6 mm; ovipositor length 1.6 mm. Antennae and cerci are broken. General body color (in alcohol) whitish, with brown and violet hypodermal pigment of weak intensity on head (frons, gena, occiput, lateral parts of clypeus, maxillae. Antenae, maxillary and labial palps, mandibles, legs, cerci, caudal filament without pigment. Scale color on upper and lower surface of body brownish. The chains in the distal part of flagellum divided into 7–9 annuli. Ratio of length to width of scapus of antenna about 1.7 ( Fig. 1 ).

Compound eyes dark brown, slightly lighter towards the contact line (in alcohol). Ratio of length to width of compound eye about 1.0; ratio of contact line to length of eye 0.52 ( Fig. 2 ). Paired ocelli shoe-shaped, dark brown, almost black with narrow white borders. Ratio of distance between inner and outer margins of ocelli to total width of compound eyes, 0.15 and 0.97, respectively.

Apical palpomere of maxillary palp about as long as previous one (0.98–1.05); ratio of lengths of 5 th and 4 th palpomeres about 1.44. Dorsal surface of 7 th, 6 th and 5 th palpomeres of maxillary palp with 15–16, 16 and 3–4 hyaline spines, respectively ( Fig. 3 ). Apical palpomere of labial palp triangularly oval, 2.6–2.7 times longer than wide, with about 18–23 sensorial cones ( Fig. 4 ). Mandibles with four distal teeth (Fig, 5).

Table 1. Length to width ratios of leg segments in female Charimachilis taurica sp.n. Таблица 1. ОтноШениЯ длины и Ширины основных сегментов ног самки Charimachilis taurica sp.n. Fore and middle tibia and femur widened ( Fig. 6 ). Middle legs shorter than fore and hind legs 1.09 and 1.06 times, respectively. Ratios of length to width of femur, tibia and tarsus as shown in Table 1. Ratio of length of 3 rd tarsomere of hind tarsus to total length about 0.34. Undersurface of femora, tibiae and tarsi with 0–1, 2–8 and 12–18 hyaline spine-like chaetae, respectively (Table 2). Ratio of length of styli to width of middle and hind coxae about 1.6 and 1.7, respectively.

Table 2. The number of hyaline spine-like chaetae on the tarsomeres, tibia and femur of female Charimachilis taurica sp.n. Таблица 2. Количество игловидных Щетинок на члениках лапки, голени и бедра у самки Charimachilis taurica sp.n.

Urocoxites I–VII with 1 + 1 eversible vesicles. Posterior angle of urosternites II–VI approximately 68–70°, VII about 64°. Length ratios of urosternites and urocoxites II–VI 0.70– 0.75, VII 0.55. Length ratios of urostyli (not including apical spines) and urocoxites II–VII 0.47–0.50, VIII 0.74 and IX 0.55. Length ratios of apical spines and urostyli II–VII 0.40– 0.50, VIII 0.39, IX 0.30. Urocoxite VII with well-developed protruding lobes between eversible vesicles. Ratio of length to width of one lobe about 0.58. ( Fig. 7 ). All thoracic tergites and urosternites; urotergites and urocoxites I–V without macrochaetae. Urotergites VI with 1 + 1, VII with 2 + 2, VIII with 3 + 3, IX with 2 + 2, X with 1 + 1; urocoxites VI with 1 + 1, VII with 2 + 2, VIII with 2–3 + 2–3 and urocoxite IX with 3 outer and 6–7 inner sublateral spines ( Figs 8, 9 ). Undersurface of distal part of urocoxites IX also with numerous medium-sized relatively long chaetae.

Ovipositor sclerotized, thickened, covered by the urocoxites IX, stout, typical of the genus Charimachilis . Gonapophysis VIII with 17 divisions ( Fig. 10 ). Apical divisions with two small lobules and subterminal needle equal in length to two apical divisions taken together. The first apical division also with about 17 sensory short chaetae and 2 thing, longer chaetae. Following two divisions with about 5 small sensory chaetae and 5–7 longer ordinary chaetae. Distal divisions, excepting apical one, with 4–5 lateral digging teeth ( Fig 10 ). Gonapophysis IX with 16 divisions ending with a somewhat curved apical horn at its end and with a subterminal chaeta as long as 3 apical divisions combined ( Fig. 11 ). This division also presents a group of several sensory spines, which are also present in the following 5–6 divisions, but their number decreases towards the base. These divisions also have about 2 chaetae, those of the external part being longer. All divisions of anterior and posterior gonapophyses with chaetae.

Male unknown.

COMPARATIVE REMARKS. Charimachilis taurica sp.n. with digging ovipositor and with 1 + 1 eversible vesicles on urocoxites II–V, belongs to the genus Charimachilis Wygodzinsky including 14 species [ Kaplin, 2019; Kaplin, Martynov, 2020]. Charimachilis . taurica sp.n. can be compared to three parthenogenetic congeners known from the Eastern Europe, namely C. ukrainensis Stach, 1958 , C. morozovi Kaplin, 2019 and C. rostoviensis Kaplin, 2020 . It differs from all these species by the ratio of distance between inner margins of paired ocelli to total width of compound eyes (0.15 in C. taurica sp.n., 0.08–0.10 in C. rostoviensis , 0.18–0.20 in C. morozovi and 0.11–0.13 in C. ukrainensis ) and length to width ratio of apical palpomere of labial palp (2.6–2.7, 2.3–2.4, 2.4–2.5 and 1.9–2.1, respectively). It also differs from C. ukrainensis and C. rostoviensis by the ratio of length to width of compound eye (1.0 in C. taurica sp.n., 0.82 in C. ukrainensis and 0.86 in C. rostoviensis ), ratio of length of contact line of eyes to their length (0.52, 0.40, 0.33–0.35); ratio of length of urostyli to urocoxites VIII (0.74, 0.9, 0.95) and urocoxites IX (0.55, 0.75, 0.46, respectively). Additionally C. taurica and C. rostoviensis are characterized by different posterior angle of urosternites II–V (68–70° in C. taurica and 80–86° in C. rostoviensis ). As for C. morozovi , it clearly differs from the new species having more annuli in chains in the distal part of flagellum (7–9 in C. taurica and 10–12 in C. morozovi ) and lateral digging teeth on anterior gonapophysis (4–5 in C. taurica and not present in C. morozovi ). The main morphological differences between the new species and C. rostoviensis , C. morozovi and C. ukrainensis are summarized in Table 3.

ETYMOLOGY. The new species is named by a suffix that refers to the historical name of Crimea Peninsula (Tauria) where it was collected.

Acknowledgements. I am grateful to Dr. Graeme B. Smith from Australian Museum Research Institute (Sydney, Australia) and to the reviewer for valuable comments, reading and editing the English language text of this paper.

Figures

Figs 1–7. Charimachilis taurica sp.n., holotype (female): 1 — scapus and pedicellus of antenna; 2 –anterior part of eyes and paired ocelli; 3 — maxillary palpus; 4 — labial palpus and labium (part); 5 — distal part of mandible; 6 — middle leg; 7 — urosternite and urocoxites VII. Scale bars: 0.1 mm. Рис. 1–7. Charimachilis taurica sp.n., голотип (самка): 1 — основной членик и стволик усика; 2 — глаЗа и парные глаЗки; 3 — нижнечелюстной Щупик; 4 — нижнегубной Щупик и нижнЯЯ губа (часть); 5 — дистальнаЯ часть верхней челюсти; 6 — среднЯЯ нога; 7 — стернит и кокситы VII сегмента брюШка. МасШтабные линейки: 0,1 мм.

Figs 8–11. Charimachilis taurica sp.n., holotype (female): 8 — urocoxite IX; 9 — urocoxite VIII; 10 — anterior gonapophysis; 11 — posterior gonapophysis. Scale bars: 0.1 mm. Рис. 8–11. Charimachilis taurica sp.n., голотип (самка): 8 — коксит IX сегмента брюШка; 9 — коксит VIII сегмента брюШка; 10 — переднЯЯ створка Яйцеклада; 11 — ЗаднЯЯ створка Яйцеклада. МасШтабные линейки: 0,1 мм.