Monochorhynchus dehongensis sp. nov.

urn:lsid:zoobank.org:act: 4393C698-5579-4D0B-BA49-BF50BB7E4F9D

Figs 1–3, 8–11

Diagnosis

This species can be easily separated from M. wahri by its dark brown coloration and the round medioventral process of the pygofer. In contrast, M. wahri has a brownish coloration and an angular medioventral process of the pygofer.

Etymology

The specific epithet refers to the collection site ‘Dehong’.

Type material

Holotype CHINA • ♂; Yunnan Province, Dehong prefecture, Longchuan County, Shihuiku; 97.8355° E, 24.3430° N; 1234.5 m a.s.l.; 3 Aug. 2024; Ai Deqiang leg.; NWAFU.

Paratypes CHINA • 6 ♀♀; same data as for holotype; NWAFU.

Description

MEASUREMENTS. Body length (incl. tegmen): male (N = 1) 13.0 mm, female (N = 6) 13.0– 13.3 mm; length of tegmen: male (N = 1) 11.5 mm, female (N = 6) 11.5–11.8 mm.

COLORATION. Body generally dark brown (Fig. 1A). Vertex with lateral marginal carinae yellow, and disc dark brown with midline white, anterior margin brown and posterior margin white (Fig. 2A). Frons dark brown, with clear white spot at middle of base, and two white spots on each inside of lateral marginal carinae, carinae brown (Fig. 2B). Gena brownish, tinged slightly darker around eye, and much darker around antennal socket and above eye, white behind antenna and in ventrolateral angle (Fig. 2C). Clypeus brown, in frontal view, with white spot at base and longitudinal brownish stripe along median carina, three carinae brown (Fig. 2B); in lateral view, each lateral part with large white spot at base, and longitudinal brownish stripe in middle (Fig. 2C). Labrum white (Fig. 2B). Rostrum with second segment gradually darker towards subapical part, apex white; apical segment dark brown (Fig. 2B–C). Eyes gray; ocelli white. Antennae brown with sensilla white (Fig. 2A–C). Pronotum dark brown, midline and margins white, each lateral part with two large brownish stripes behind eye, some white tubercles, and row of smaller yellow tubercles (Fig. 2A–C). Mesonotum brown, tinged darker between lateral carinae, with two longitudinal lighter lines on lateral sides of median carina, and two white spots behind yellow lateral angles; median carina white, lateral carinae white with broader white markings along them, and dark spots at anterior quarter, slightly widened at middle and expanding inwards near posterior margin; scutellum white (Fig. 2A, C). Tegula brownish, with darker stripe adjacent to posterior margin (Fig. 2A). Tegmen generally dark brown, almost every apical cell with white to yellowish spots adjacent to margins, basal half with large yellowish region with fewer dark markings, delimited by MP, MP 2, subapical line, and postclaval margin, radial cell with four white spots, C2 with two white spots, subapical line with some white spots; veins mottled, mainly dark brown, with yellow spots (Fig. 2F). Wing semitransparent, with brown to dark brown markings. Legs yellowish, fore and middle legs with brown stripes on first three segments, tibiae and tarsi generally brown; hind leg lighter than first two legs, with darker markings at apex of tibia (Fig. 2B–C, E). Abdomen dark brown on dorsal side with many small yellow spots, and lighter on ventral side.

HEAD AND THORAX. Vertex with width of base 1.9 × as long as length of midline (Fig. 2A). Antenna with pedicel about 2.6 × as long as widest portion, slightly constricted apically (Fig. 2A–C). Pronotum with small tubercles arranged in lines parallel with posterior margin (Fig. 2A). Mesonotum with few small tubercles along posterior portion of median carina (Fig. 2A). Tegmina about 3.7 × as long as widest portion (Fig. 2F). Metatibiotarsal formula: 5-(7–8)-6 (Fig. 2E).

MALE GENITALIA. Anal tube tongue-shaped in dorsal view, with midline length about 1.6 × as long as basal width (excluding basal angles), apex round, basal half with trapezoidal ventral opening, lateral margins slightly incised medially, becoming elevated and infolded posteriorly (Fig. 3B); in lateral view, basal third relatively straight, with two basal angles protruding ventrad and dorsal process protruding dorsocaudad before turning point, apical two thirds triangular and inclined ventrad, with dorsal margin straight, paraprocts extending beyond apex of anal tube (Fig. 3A). Pygofer rectangular in ventral view, with medioventral process slight and round (Fig. 3E). Gonostyli subrectangular in dorsal view, with apical process extending inwards, lamina sclerotized and C-shaped (Fig. 3C); in lateral view, with auricular process protruding outwards, blunt and hirsutiusculus at apex (Fig. 3D); in caudal view, apical margin irregular, deeply concave in ventral quarter, with apical process narrow-acicular at ventral third, and small angular process at dorsal third (Fig. 8C). Phallic complex robust and broad, in dorsal view, periandrium gourd-shaped, with left margin double-arched, right margin arched in basal portion and relatively straight in apical portion, five characteristic processes: 1) elongate and sinuous process (P 1) originating from mid-left margin, extending beyond right margin, with main portion curved caudad, apex acute and recurving cephalad; 2) broad and curved process (P 2) originating from mid-left margin, following apical portion of left margin, with apex acute and directed right-caudad, slightly exceeding apex; 3) short and spinous process (P 3) originating from subapical right margin, extending caudad, with apex acute; 4) elongate and triangular process (P 4) originating from apical dorsum, extending cephalad to basal third, with apex straight and acute; 5) broad and flat process (P 5) adjacent to P 4 on its right dorsal side, also originating from apical dorsum, and extending cephalad to basal third, with apex constricted and curved rightwards (Fig. 3F). In lateral view, P 1 arched dorsad basally, sinuous and gradually tapered distad, P 2 horn-shaped and upcurved, P 3 short and extending to level of P 2 apex, P 4 and P 5 extending dorsocephalad; endosoma small; aedeagus cylindrical and sclerotized at base (Fig. 3G–H).

FEMALE GENITALIA. Pygofer without dorsolateral tergal processes and ventrosternal processes. Medioventral plate with dorsolateral angles obtusely angular, dorsal margin slightly convex at each lateral quarter. Intermedia plates hammer-shaped, not directly connected to other sclerotized structures, broad at bases, narrow at apices that meet medially, displaying faint dividing line at middle. Intergonocoxal plate IX with ventral margin slightly incised at middle, sclerotized parts double-C-shaped and widened subapically, and with short rod along median incision. Gonocoxa IX with dorsolateral angle angularly convex. Gonoplac in caudal view, broadest near base and apex, obtusely angular at base, slightly incurved at apex. Mediodorsal sclerotized plate semi-circular and slightly concave at middle (Figs 2D, 8F).

Host plant association

An unidentified bamboo species (Poaceae Barnhart: Bambuseae Kunth ex Dumort.), likely belonging to the genus Bambusa Schreb., Thyrsostachys Gamble, or Dendrocalamus Nees.

DNA Barcode

The COI sequence was uploaded to the Nucleotide database of GenBank with the accession number (PX568410).

Remarks

Unfortunately, owing to delicate hind wings, we were unable to fully document them.

In this species, between gonoplacs and medioventral plate, there is a pair of intermedia plates (imP), strongly sclerotized (Figs 2D, 8F). Morphologically, these plates resemble the gonocoxae VIII of Proutista moesta and P. pseudomoesta in shape and position (Chen et al. 2025); however, their anteroventral margins are not directly connected to the posterodorsal margin of sternite VIII, and they coexist with the medioventral plate (mvP). Presumably, these unique intermediate plates are characteristic of the entire genus. This structure also likely represents an intermediate state of reduction of gonapophyses VIII, constituting a transitional stage between the well-developed condition (as in subtribe Zoraidina Muir, 1913) and the complete absence observed in genera (e.g., in Proutista and Shizuka).