Dianphasma chongqingensis Qian & Xie, 2023

Qian, Yu-Han, Xie, Chong-Xin, Wen, Jun & Wang, Yu, 2023, Review of stick insects (Insecta: Phasmatodea) from Yintiaoling Nature Reserve of China, with description of two new species, Zootaxa 5257 (1), pp. 17-39 : 35-37

Dianphasma chongqingensis Qian & Xie sp. nov. ( Figures 23–26 )

Material examined. Holotype female, China, Chongqing, Wuxi County, Yintiaoling National Nature Reserve, Linkouzi protection station, 1,270 m, 14 Aug. 2022, Leg. Chong-Xin Xie . Paratypes. 2 males and 2 eggs, same data as holotype .

Description. Female. General coloration of body brown to dark brown, with irregular dark brown or black marking and off-white pilosity, some tiny granules mainly concentrated at the head, thorax, and terga 2–5. Head. Squarish, longer than broad, roughly as long as pronotum; vertex flat and occiput slightly convex in lateral view. Antennae filiform, much longer than forelegs, scapus rectangular and flattened, slightly longer than pedicellus, pedicellus cylindrical, longer than the third segment. Compound eyes rounded and projecting, about 1/3 times as long as gena. Thorax. Unarmed. Pronotum rectangular, longer than broad, transverse and longitudinal sulci crossing the middle area. Mesonotum almost parallel-sided, approximately 3 times as long as the pronotum, with some coarse rugose, mediolongitudinal carina distinct. Metanotum as long as it is wide, mediolongitudinal carina weak. Tegmina absent, alae squamiform, not reaching the anterior margin of median segment. Median segment nearly as long as metanotum, mediolongitudinal carina same as metanotum. Abdomen. Cylindrical, lacking armature, with some irregular rugose. Terga 2–7 without distinct mediolongitudinal carina, tergum 2 with a short transverse ridge at the hind margin, tergum 3 with two small granules at the hind margin, terga 4–6 hind margin with distinct lobe projecting and gradually becoming larger, terga 6–7 narrowed gradually, tergum 7 with a small hump at the hind margin, terga 8–9 trapezoidal, tergum 8 anterior narrowed, tergum 9 posterior narrowed, two segments with a distinctly broad median ridge in the dorsal view. Sternum 7 lacking praeopercular organ. Anal segment as long as the 9 th tergum, with a weakly broad median ridge in the dorsal view, hind margin rounded, middle with a triangular notch. Subgenital plate reaching to the middle of the anal segment in the lateral view, nautiform in the ventral view, anterior narrowed and gradually broadening to the middle area, median widest and then tapering posteriorly, apically rounded. Cerci cylindrical, apices obtuse. Legs. Brown with irregular black or dark brown stripes, unarmed, all carina present. Profemora distinctly curved basally and slightly longer than corresponding tibiae. Meso- and metafemora as long as corresponding tibiae.

Male. Slenderer than female. General coloration of body brown to dark brown, with irregular dark brown or black markings and off-white pilosity. Head. Squarish, longer than broad, roughly as long as pronotum, vertex flat, occiput weakly convex in lateral view. Antennae filiform, much longer than forelegs, scapus rectangular and flattened, as long as pedicellus, pedicellus cylindrical, shorter than the third segment. Compound eyes rounded and projecting, approximately 1/3 times as long as gena. Thorax. Unarmed, with distinctly mediolongitudinal carina. Pronotum rectangular, longer than broad, with sparsely tiny granules; transverse and longitudinal sulci crossing the middle area; behind transverse sulci, a short carina at each side of longitudinal sulci. Mesonotum almost parallelsided, approximately 4 times as long as pronotum, with some coarsely rugose and irregular black stripes. Metanotum rectangular, approximately 1/4 of mesonotum. Tegmina absent, alae squamiform, not reaching the anterior margin of median segment. Median segment nearly as long as metanotum. Abdomen. Cylindrical, lacking armature. Terga 2–6 about the same length, terga 7–9 and anal segment gradually decreasing in length. Anal segment hind margin almost truncated in the dorsal view. Poculum spoon-shaped, projecting over the 1/2 of anal segment, apically rounded in ventral view. Cerci long, cylindrical and apically curved inward, apices obtuse. Legs. Slender and unarmed, all carina present. Profemora slightly basally curved and as long as corresponding tibiae; mesofemora slightly longer than corresponding tibiae; metafemora slightly shorter than corresponding metatibiae.

Eggs. Capsule nearly oval, off-white and with irregular black or brown retirugose. Micropylar plate spadeshaped, anterior apex subacute, posterior apex much broader than the anterior apex. Micropylar cup distinctly, a light-yellow semicircular prominence projecting from the anterior of a short median line and covering part of the micropylar cup. Operculum almost circular, slightly convex, central with a black capitulum, surrounded by irregular small papillae, the outer ring with coarse granules. Polar apex weakly concave.

Measurements (mm). Female. Body length 57.4; head length 3.5; pronotum length 3.9; mesonotum 12.1; metanotum 4.1; median segment 3.8; profemora 11.3; mesofemora 9.0; metafemora 13.0; protibiae 10.8; mesotibiae 8.5; metatibiae 12.5. Male. Body length 55.2–55.7; head length 2.8–3.0; pronotum length 3.0–3.1; mesonotum 11.5–12.9; metanotum 3.0–3.2; median segment 3.0–3.2; profemora 14.1–14.7; mesofemora 10.1–10.5; metafemora 14.5–15.8; protibiae 12.9–13.7; mesotibiae 9.0–9.5; metatibiae 15.3–16.8. Egg. Length 2.9–3.1, width 1.5–1.7, height 1.4–1.6.

Etymology. This specific epithet is derived from the name of Chongqing municipality, which is one of the famous cities located in Southwest China.

Distribution. China (Chongqing).

Diagnosis. Notable features of this new species show that it should belong to the endemic genus Dianphasma of China, such as body covered with fine hairs; head rather long, without conical spines between eyes; antennae longer than profemora; metanotum as long as median segment; fore wings absent, hind wings squamiform; leg short, without any teeth or lamellae; posterior margins of terga 1 st –8 th with central elevations respectively; anal segment rather long, apex not pointed ( Chen & He, 1997a).

There are four species recorded in this genus. In D. sparsigranulatum Ho, 2017 and D. yui Ho, 2017 , tergum 4 lacking tubercle or flattened elevation. In D. microptera Chen & He, 1997 , with a pair of humps at anterior of terga 4–5; In D. cheni Ho, 2013 , ocelli indistinct, subgenital plate apex pointed; but the new species can be distinguished by terga 4–6 have a distinct projecting lobe and gradually become larger, lacking ocelli.

Figures

FIGURE 23 Dianphasma chongqingensis sp. nov., holotype, female, A–H. A. habitus, dorsal view; B. habitus, ventral view; C. habitus, lateral view; D. head, dorsal view; E. head, lateral view; F. terminalia, dorsal view; G. terminalia, lateral view; H. terminalia, ventral view.

FIGURE 24 Dianphasma chongqingensis sp. nov., paratype, male, A–H. A. habitus, dorsal view; B. habitus, ventral view; C. habitus, lateral view; D. head, dorsal view; E. head, lateral view; F. terminalia, dorsal view; G. terminalia, lateral view; H. terminalia, ventral view.

FIGURE 25 Dianphasma chongqingensis sp. nov., paratype egg, A–D. A. dorsal view; B. lateral view; C. top view; D. polar view.

FIGURE 26 Dianphasma chongqingensis sp. nov. in the wild. A. female; B. male.