Coryphophthalmus obscurus, Kaplin, 2019

Kaplin, Vladimir, 2019, Taxonomic review of the genera Trigoniophthalmus Verhoeff and Coryphophthalmus Verhoeff (Archaeognatha, Machilidae) with descriptions of two new species of the genus Coryphophthalmus from Serbia, Zootaxa 4661 (2), pp. 371-384 : 376-378

Coryphophthalmus obscurus Kaplin, sp. nov.

Figs. 9–18

Diagnosis. Among the species of the genus Coryphopgthalmus with 2 + 2 exsertile vesicles in urocoxites II–V C. obscurus sp. nov. differs in its relatively short body and antennae, elongated compound eyes, tarsus with numerous spine-like setae and ovipositor with a great number of divisions.

Description. Holotype female: body length 6.3 mm; body width 1.5 mm; cercal length 2.6 mm; total eyes width 0.64 mm, eye length 0.35 mm; paired ocelli width 0.16 mm, length 0.13 mm. Coxal styli length 0.65–0.75 mm. Ovipositor length 3.8 mm.

General body color (in alcohol) whitish, with brown-violet hypodermal pigment of medium intensity on head and of low intensity on coxae. Scale color on surface of body dark brown. Antennal length slightly more than half the body length. Distal chains of flagellum divided into 9–11 annuli ( Fig. 10 ). Cercal length about 0.4 times body length, with two apical spikes, divided into 15 or 16 annuli ( Fig. 18 ). Clypeus of males without long thin bristles. Two apical annuli of cerci without lateral hyaline macrochaetae. Rest of annuli of cerci with two inner lateral macrochaetae.

Compound eyes bicolored (in alcohol), from brown in central part to black in the peripheral parts. Length to width ratio of compound eye 1.09; ratio of line of contact to length of eyes 0.59. Paired ocelli submedian, subtriangular, dark brown with narrow white border, 1.2 times wider than long. Ratio of distance between inner and outer margins of ocelli to total width of compound eyes 0.21 and 0.59, respectively ( Fig. 9 ).

Apical palpomere of maxillary palp 0.82–0.83 times as long as the preceding one; ratio of length of 5th to 4th palpomere 1.5 ( Fig. 11 ). Dorsal surface of 5th, 6th and 7th palpomeres of maxillary palp with 3, 10–11 and 12–14 hyaline spines, respectively. Apical palpomere of labial palp triangularly oval, 2.7–2.8 times longer than wide ( Fig. 14 ). Mandibles with 3–4 distal teeth ( Figs. 12, 13 ).

Fore and middle femora and tibiae widened ( Fig. 15 ). Ratios of length to width of femur, tibia and tarsus as shown in Table 2 . Middle legs shorter than fore and hind legs. Fore tarsus and tibia 1.1 and 1.2 times longer, respectively, than those of middle legs; hind tarsus and tibia 1.3 and 1.5 times longer, respectively, than those of middle legs. Ratio of length of apical hind tarsomere to total length of hind tarsus 0.34–0.35. Ventral surface of coxa with long thin bristles, those of trochanter and femur thicker. Fore, middle and hind tarsi and hind tibia with pigmented spine-like setae. Number of spine-like setae given in Table 3 .

Middle and hind legs with coxal styli. Ratio of length of styli to width of middle and hind coxae 1.47–1.53 and 1.39–1.42, respectively ( Fig. 16 ).

Urocoxites I, VI and VII with 1+1, II–V with 2 + 2 eversible vesicles. Posterior angle of urosternites II–VI 77– 88°. Inner posterior lobes of urocoxites VII protruding. Width to length ratio of protruding lobe about 2.7. Length ratios of urosternites, urocoxites and urostyli given in Table 4 .

Thoracic tergites, urotergites I–III, urosternites and urocoxites I–VIII without macrochaetae; urotergites IV–V with 1–2 + 1–2, VI with 2 + 2, VII with 2–4 + 2–4, VIII with 2 + 2, IX with 4 + 4 and X with 2 + 2 sublateral macrochaetae. Urocoxites IX with 3–5 + 3–5 inner sublateral macrochaetae, without outer macrochaetae.

Ovipositor slender, elongate, visibly surpassing apex of styli IX. Anterior and posterior gonapophyses with approximately 54 or 57 divisions, respectively ( Fig. 17 ). Four basal divisions of anterior gonapophyses and 38 or 39 basal divisions of posterior gonapophyses glabrous. Distal spines of gonapophyses as long as three apical divisions combined. Apical divisions of anterior and posterior gonapophyses with 4 or 5 setae.

Material examined. Holotype female (on slides). Serbia, Zlatibor District , 43°32′38′′N, 19°39′058′′E, Prij- epolje, elev. 560 m, Lim valley, mixed forest, under stones, 21.06.2017 (V. G. Kaplin ).

Etymology. The species name obscurus is Latin for “dark”, referencing the predominant color of the body scales.

Figures

FIGURES 9–18. Coryphophthalmus obscurus sp. nov., holotype female. 9) Eyes and paired ocelli, front view. 10) Chain of distal part of flagellum. 11) Maxillary palp. 12, 13) Distal part of mandible. 14) Labial palp, with part of labium. 15) Fore leg (part). 16) Middle coxa, with stylus. 17) Urocoxite IX, with anterior gonapophyses. 18) Apex of cercus. Scale bars: 0.1 mm.