Duolandrevus (Eulandrevus) hainanensis Liu, He & Ma, 2015

Zheng, Yanna & Ma, Libin, 2021, Taxonomy of the genus Duolandrevus Kirby, 1906 (Orthoptera: Gryllidae; Landrevinae) from China with a new species of the subgenus Eulandrevus Gorochov, 1988, Zootaxa 4942 (2), pp. 252-268 : 261-262

Duolandrevus (Eulandrevus) hainanensis Liu, He & Ma, 2015

( Fig 8–9 )

Duolandrevus (Eulandrevus) hainanensis Liu , et al., 2015: 596; Gorochov, 2016: 27; Zhang, et al., 314; Chen, et al., 2019: 553–562

Examined materials. 4 males. China: Hainan, Ledong, Jianfengling , Aug. 19, 2019, coll. He, Zhixin and Zhang, Tao ( SNNU) ; 2 males. China: Hainan, Wuzhishan , Aug. 17, 2019 coll. He, Zhixin and Zhang, Tao ( SNNU) .

Measurements (mm). Male: BL 20.39±2.55; HL 3.78±1.12; HW 5.47±0.20; PL 2.70±0.17; PW 5.25±0.15; FWL6.74±0.42; HFL 9.63±0.02; HTL 5.10±0.04; Female: BL 16.90±0.20; HL 3.18±0.12; HW 4.74±0.10; PL 2.95±0.10; PW 4.76±0.11; FWL 3.63±0.18; HFL 10.21±0.23; OL 9.62±0.18.

Description. Male: Body sized large for this genus. Head smooth and shining, conspicuously wider than pronotum. Vertex broad and flattened, weakly inclined. Frontal rostrum slightly convex in frontal view, somewhat wide in dorsal view and wider than antennal scape. Face transversely broad, area of antennal socket and area of lower side of eye distinctly depressed, between two areas ridged; cheek shiny and plump. Median ocellus small and transversely oval-like; lateral ocelli large and rounded. Clypeus extremely small, distal narrowed portion is short. Labrum rhombus-like, with angle lateral margins and concave apically. End section of maxillary palpi longer than the third; end section of labial palpi longer than remainder sections, depressed and widened.

Pronotum widened and depressed; anterior margin concave and arch-like, posterior margin straight. Middle of both lateral edges slightly convex. Hindwings aplasia, small (reaching posterior margin of metanotal gland) and entirely covered by forewings. Tegmina reaching middle of the fifth abdominal tergite. The basal region of forewing elevated and slightly higher than the rest of wing surface, with 1A and 2A veins converging apically. Oblique veins six. Chord veins three, proximally connected together, converging on CuA veins. Mirror inconspicuous, replaced by multiple irregular wing cells, of them, most of proximal ones somewhat larger than the apical ones. A chord and wing cells connected by several veins (from two to four). Apical field armed with reticulated veins. Lateral field bearing six branches of Sc vein.

Both inner and outer tympanum oval-like and inner slightly larger than outer one. Hind tibiae equipped with spines on the half of proximal portion and spurs on distal part (numbered 4:5), and with six apical spurs, of them, the inner apical numbering three, the ventral one shortest and remainder ones nearly equal to each other, and the ventral one shorter than 1/2 of remainder ones; the outer apical spur numbering two, the ventral one shorter than the dorsal, but longer than 1/2 of them; as a whole, outer apical spurs longer than the inner ones. First tarsus of hind leg armed with six spines respectively on sides. Super-anal plate simple, trapezoidal, about two times longer than width. Subgenital plate pike-liked.

Genitalia ( Fig. 9 ): Genitalia tapering distally in dorsal view. Middle lobes of epiphallus short. Lateral lobes of epiphallus about three times longer than the middle lobe, its tip not bifurcate, but in lateral view with a small hook on the dorsal side. Epiphallus ventrally possessing two lateral projections, the anterior one short and somewhat as long as epiphallic lateral lobe, and the posterior one about 1.8 times longer than the former. Ectoparameres acute, about two times longer than epiphallic middle lobe.

Coloration: Body color dark brown. Upper half portion of clypeus dark brown and lower half portion yellowish. Labrum yellowish-brown. Tegmina brown. Femora yellowish-brown, with tibial and claw brown. Cercus yellowishbrown proximally and apically dark brown.

Female: Similar to male. Forewing reaching posterior to the second abdominal segment, with longitudinal veins, which short inside and gradually lengthening outward. Ovipositor brown, smooth and arrow-shaped, slightly longer than posterior femur.

Remark. This species is related to Duolandrevus (Eulandrevus) axinus ( Gorochov, 1988) , but the lateral lobes of the epiphallus are different. In Duolandrevus (Eulandrevus) hainanensis , anterior edge of epiphallus sharp, posterior one obtuse; but in Duolandrevus (Eulandrevus) axinus , both anterior and posterior edge of epiphallus lateral lobe sharp. Size of body as well as number and size of wing cells replacing mirror are varied among individuals of species. The chord veins are different in this species. They proximally connect together in most individuals, and in some individuals, the third chord converges with wing cells that replacing mirror. Most literature record this species does not possess hindwings ( Chen et al., 2019; Gorochov, 2016; Liu et al., 2015; Zhang et al., 2017a). We found it bears hindwings. These wings are undeveloped, rather small (slighter longer than posterior margin of metanotal gland) and entirely covered by forewings.

Figures

FIGURE 8. Body of Duolandrevus (Eulandrevus) hainanensis. A. male; B. female. Scale bar: 10 mm.

FIGURE 9. Genitalia of Duolandrevus (Eulandrevus) hainanensis. A. dorsal viewed; B. lateral viewed; C. ventral viewed.