Monochorhynchus psammochroma Chen, Wang & Zhang, 2026, sp. nov.

Monochorhynchus psammochroma sp. nov. urn:lsid:zoobank.org:act: 58B2F14F-7746-42C2-B966-536528F8A81F Figs 6–8 Diagnosis This species closely resembles M. wahri in general coloration, but can be separated from it by its truncated medioventral process of the pygofer and bifurcated anal apex in profile. In contrast, M. wahri with angular medioventral process of the pygofer and anal apex single in profile. Etymology The specific epithet derives from the Greek ‘psammos’ (‘sand’) and ‘chroma’ (‘color’), referring to the distinctive sandy-yellow coloration of the tegmina and body; the name is in apposition. Type material Holotype CHINA • ♂; Fujian Province, Quanzhou City, Dehua County, Shuikou Town; 6 Nov. 1974; Li Fasheng leg.; CAU. Description MEASUREMENTS. Body length (incl. tegmen): male (N = 1) 11.9 mm; length of tegmen: male (N = 1) 10.4 mm. COLORATION. Body generally brownish (Fig. 6A–C). Vertex with lateral marginal carinae white, and disc brown with midline lighter, anterior and posterior margins white (Fig. 6A). Frons brown, with clear white spot at middle of base, and five white spots inside of each lateral marginal carina, of small, medium, small, large, and medium size, respectively, carinae white (Fig. 6B). Genae brown, tinged white around antennal socket and behind it, and in ventrolateral angle (Fig. 6C). Clypeus brown, in frontal view, with longitudinal white stripes along carinae, three carinae white (Fig. 6B); in lateral view, each lateral part with large white spot at base (Fig. 6C). Labrum white (Fig. 6B). Rostrum with second segment white at base and apex, gradually darker towards middle; apical segment with base brownish, darker distad (Fig. 6C). Eyes dark gray; ocelli white. Antennae brown with sensilla white (Fig. 6A–C). Pronotum brown, midline and margins yellow, each lateral part with two large brownish stripes behind eye, some white tubercles, and row of smaller white tubercles (Fig. 6A–C). Mesonotum brownish, with longitudinal brown stripes along carinae, round brown marking anterior to scutellum, and two white spots behind lateral angles; three carinae generally white, lateral ones with dark spots at anterior quarter, white spots at posterior third slightly expanding inwards; scutellum white to yellowish (Fig. 6A, C). Tegula brownish, with brown stripe adjacent to posterior margin (Fig. 6A–B). Tegmen generally brownish, almost every apical cell with white spots adjacent to margins, basal half with large white region with fewer dark markings, delimited by MP, CuA 2, first m-cu, and postclaval margin, radial cell with four white spots, C2 with two white spots expanded posteriorly to L-shaped, subapical line with some white spots; veins mottled, mainly brown, with yellow spots (Fig. 6F). Wing semitransparent, tinged brownish in apical quarter, and brown along veins, with subquadrate brown near middle, from anterior margin to CuA 1, another slightly darker one near base, from MP to A 1, and small oval spot at apex of CuA 2 with color lighter than first two; veins brown (Fig. 6D). Legs yellowish, with brown stripes excluding tarsi generally brown; hind leg with fewer markings than fore and middle legs, tinged darker markings at apex of tibia (Fig. 6B–C, E). Abdomen brown on dorsal side with many small yellow spots, and lighter on ventral side (Fig. 6A, C). HEAD AND THORAX. Vertex with width of base 2.3 × as long as length of midline (Fig. 6A). Antenna with pedicel about 2.6 × as long as widest portion, anterior apical angles slightly protruding (Fig. 6A–C). Pronotum with small tubercles arranged in lines parallel with posterior margin (Fig. 6B–C). Mesonotum with many small tubercles along three carinae (Fig. 6A). Tegmina about 3.5 × as long as widest portion (Fig. 6F). Metatibiotarsal formula: 5-8-6 (Fig. 6E). MALE GENITALIA. Anal tube trapezoidal in dorsal view, with midline length about 1.4 × as long as base width (excluding basal angles), apex relatively truncated, basal half with quadrate ventral opening, lateral margins relatively straight, elevated and infolded after middle (Fig. 7B); in lateral view, basal third relatively straight, with two basal angles protruding ventrad and dorsal process protruding dorsocaudad before turning point, apical two thirds inclined ventrad and bifurcated apically, ventral lobe smaller than dorsal lobe, paraprocts extending beyond apex of anal tube (Fig. 7A). Pygofer rectangular in ventral view, with medioventral process subtrapezoidal and relatively truncated, apex shorter than base (Fig. 7C). Gonostyli subrectangular in dorsal view, with apical process round and extending inwards, lamina sclerotized and C-shaped (Fig. 7E); in lateral view, with auricular process protruding outwards, blunt and hirsutiusculus at apex (Fig. 7D); in caudal view, apical margin irregular, shallowly concave in ventral quarter, with semicircular apical process at middle, and small hook near dorsal angle (Fig. 8E). Phallic complex robust and broad, in dorsal view, periandrium reniform, with left margin arched outwards in postmedian portion, right margin shallowly concave from base to subapical portion, apex constricted, five characteristic processes: 1) elongate and sinuous process (P 1) originating from mid-left margin, extending before longitudinal midline; 2) broad and curved process (P 2) originating from mid-left margin, following apical portion of left margin, with apex obliquely truncated and directed right-caudad, exceeding apex; 3) very 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 middle, 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 slightly curved rightwards, in additional with a small thorn near apex (Fig. 7G). In lateral view, P 1 broad at base, abruptly constricted cephalad into hook, tapered distad and curving dorsad, P 2 chickenclaw-shaped and extending caudad, P 3 short and extending before level of P 2 apex, P 4 broad at base and gradually tapered at apex, extending dorsocephalad, P 5 broad-foliar in main portion, with small thorn at subapical portion, apex spinous and extending cephalad to middle of P 1; endosoma small; aedeagus cylindrical and sclerotized at base (Fig. 7F, H). Fine morphology (Figs 9–11) General structure of the mouthparts The mouthparts of M. dehongensis sp. nov. conform to the typical piercing-sucking type observed in the Derbidae, originating posterior to the cephalic capsule and comprising three main components: 1) a cone-shaped labrum (Lm), 2) a three-segmented tubular labium (Lb), and 3) a stylet fascicle (Sf). The labrum (Fig. 9A–B, G) arises from the apex of the anteclypeus and extends along the median longitudinal groove of the second labial segment. It measures approximately 410 μm in length and 85 μm in basal width, overlapping about one-fifth to one-quarter of the groove. The labral surface is predominantly wrinkled, except for the smooth distal apex. The labium (rostrum) features a narrow longitudinal groove (Lg) along its anterior surface (Fig. 9A). The first segment measures 400 μm in length, with basal and apical widths of 200 μm and 270 μm, respectively. It is tubular, slightly expanded distally in posterior view (Fig. 10D), and obscured by the clypeus (Cl) in anterior view (Fig. 9A–B). The lateral surface exhibits slight oblique striations (Fig. 10A). A short membranous articulation connects the first and second segments. The second segment is the longest, measuring 1255 μm in length and expanding distally to a maximum width of 295 μm. The lateral surfaces bear horizontal striae and are densely covered with numerous small papillae (pa) (Fig. 9B–C, F). The posterior surface presents an indistinct midline groove in its distal third and an extended apical margin that overlaps the base of the third segment (Fig. 10B, E). The anterior surface displays a slightly convex medial apical margin (Fig. 9D–E). The third segment, the shortest, is strongly expanded distally (350 μm in length; 420 μm in width) and has longitudinal striae on its apical surface (Figs 9E, 10B, E). The underside bears a crater-like protrusion surrounding the stylet fascicle, with a distinct honeycomb-like surface texture (Fig. 11A–B). The stylet fascicle is needle-like, approximately 26 μm in diameter, and dorsoventrally compressed in cross-section (Fig. 10H). The mandibular stylets are laterally compressed, semicircular, and symmetric, with lengths approximately 2.9–3.0 × their maximum width, and remain separated dorsally and ventrally. The maxillary stylets form an oval-shaped bundle, enclosing a large dorsal food canal and a smaller ventral salivary canal. The maxillary connection apparatus comprises a three-locking system: (1) The dorsal lock includes four processes: on the left maxilla, the upper angular (A) and lower auricular (B); on the right, the upper quadrate (A’) and lower angular (B’); A interlocks with B’, and A’ with B. (2) The median lock involves three processes: angular processes (C, D) on the left maxilla interlocking with an auricular process (C’) on the right. (3) The ventral lock consists of an angular process (E) on the left and a blunt process (E′) on the right. Sensilla Five main types of sensilla were observed: sensillum chaetica (CH 1, CH 2, CH 3), peg-in-pit uniporous sensillum (PPSU1, PPSU2), sensillum basiconica (BSN1, BSN2), multiporous dome-shaped sensillum (DSSM), and uniporous peg sensillum (PGSU). On the labrum, one or two CH 2 occur(s) along the anterior midline (Fig. 9G). The first labial segment bears sparse CH 3 on the posterior surface, CH 1 and CH 2 in lateral rows, and BSN1 along the lateral margins (Fig. 10A, D). The second segment shows several rows of CH 2 and CH 3, and numerous PPSU1 (clustered finger-li