Megatachycines rectangularis, Yin & Xiao & Luo, 2022

Yin, Kesong, Xiao, Yunxue & Luo, Changqing, 2022, A new species of the genus Megatachycines (Rhaphidophoridae: Aemodogryllinae Aemodogryllini) from Guizhou, China, Zootaxa 5154 (2), pp. 246-250 : 247-249

Megatachycines rectangularis sp. nov.

( Figs. 1–3 )

Description. Male. Body medium sized ( Figs. 1A–C ). Vertex of head divided into two conical tubercles, bases of the well-developed tubercles slightly drawn together, obtusely rounded apices obviously separated ( Figs. 1D, E ). Eyes oval, protruding forward ( Figs. 1D, E ). Anterior margin of pronotum straight, posterior margin protruding caudad, ventral margin arc-shaped; posterior margin of mesonotum protruding caudad; posterior margin of metanotum slightly protruding caudad.

Legs long and slender. Fore femur about 1.6 times longer than the pronotum, ventrally unarmed, internal genicular lobe with 1 small spine, external genicular lobe with 1 long spine; fore tibia ventrally with 2 inner spines and 2 outer spines, apex with 1 pair of small spines on dorsal surface and 1 pair of long spines on ventral surface, between the paired ventral spines with 1 small spine. Middle femur ventrally unarmed, internal and external genicular lobes with 1 long spine respectively; middle tibiae ventrally with 1–2 inner spines and 1 outer spine, apex with 1 pair of small spines on dorsal surface and 1 pair of long spines on ventral surface, between the paired ventral spines with 1 small spine. Hind femur ventrally with 5–8 inner spines and without outer spine; hind tibia dorsally with 59–62 inner spines and 59–68 outer spines, arrange in groups, ventral and dorsal surface with a pair of small sub-apical spines respectively, apex with 1 pair of long dorsal spines and 1 pair of long ventral spines; the longest dorso-apical spine reaching the apex of the dorso-apical spine of hind metatarsus ( Fig. 1F ). Hind metatarsus keeled beneath.

Well-developed epiproct extending backwards and nearly rectangular, posterior margin of epiproct rounded ( Fig. 1G ). Paraproct shorter than epiproct ( Fig. 1H ). Dorsolateral lobes of male genitalia distinctly sclerotized, basal part with a large projection; apex of median lobe with 1 pair of dorsal lobules and 2 pairs of ventral lobules; epiphallus of male genitalia like the shape of ligule-like, rather small ( Figs. 2A, B ). Male subgenital plate bilobed in the apical area.

Female. General appearance similar to that of male ( Figs. 3A–C ), but the fore femur of some female specimens ventrally with 1 spine, and hind femur ventrally with 7–8 inner spines. Ovipositor about half the length of hind femur; base of ovipositor broad, narrowing to apex; apex pointed and slightly curved upwards; almost indistinct denticles on ventral edge of distal part of inferior valves ( Fig. 3D ). Subgenital plate nearly triangular and with a projection in the middle part of hind margin ( Fig. 3E ).

Coloration. Body yellowish brown, mottled with dark brown and black stripes. The apex of the two conical tubercles black. Face with four indistinct longitudinal stripes. All legs with dark brown annular stripes, hind femora with irregular brown stripes.

Material examined. Holotype: 1♂, Honghua Village , Yuping Dong Autonomous County, Tongren City , Guizhou Province, 26.IX.2021, coll. Ben Hong. Paratypes: 2♂, 4♀, same data as the holotype .

Measurements (mm). Body: ♂ 15.79–16.20, ♀ 15.55–16.52; pronotum: ♂ 5.09–5.11, ♀ 6.17–6.43; fore femur: ♂ 7.99–8.57, ♀ 9.18–9.45; hind femur: ♂ 17.34–17.35, ♀ 19.17–19.59; ovipositor: ♀ 9.45–10.12.

Distribution. China (Guizhou).

Discussion. This new species is similar to Megatachycines elongatus ( Qin, Liu & Li, 2017) in the morphology of the lateral lobes of male genitalia, but can be distinguished from the latter in several respects. First, the shape of the epiproct of male and the shape of the subgenital plate of female are different between these two species. Second, the number of spines on the hind tibiae of this new species is slightly lower than that in Megatachycines elongatus ( Qin, Liu & Li, 2017) . Third, the coloration of the body is obviously different between the two species.

Etymology. The name of the new species refers to the shape of the male epiproct.

Figures

FIGURE 1. Megatachycines rectangularis sp. nov. (male). A. habitus, dorsal view; B. habitus, lateral view; C. habitus, ventral view; D. head, frontal view; E. vertex of head, showing conical tubercles; F. hind tarsus, lateral view; G. epiproct, dorsal view; H. paraproct, lateral view.

FIGURE 2. Male genitalia of Megatachycines rectangularis sp. nov.. A. genitalia, dorsal view; B. genitalia, ventral view.

FIGURE 3. Megatachycines rectangularis sp. nov. (female). A. habitus, dorsal view; B. habitus, lateral view; C. habitus, ventral view; D. ovipositor, lateral view; E. subgenital plate, ventral view.