Mestus cruciatus, Ren, Feng-juan, Xie, Qi & Qin, Dao-zheng, 2015

Ren, Feng-juan, Xie, Qi & Qin, Dao-zheng, 2015, Mestuscruciatus, a new delphacid species from southwest China with some remarks on the genus (Hemiptera, Fulgoromorpha, Delphacidae), ZooKeys 545, pp. 67-74 : 70-72

Taxon classification Animalia Hemiptera Delphacidae

Mestus cruciatus sp. n. Figures 1-7, 8-19

Description.

Brachypterous: Total length (from apex of vertex to the tip of abdomen): male (n=16) 2.40-2.75 mm, female (n=15) 2.65-2.88 mm; tegmina length: male (n=16) 1.85-1.90 mm, female (n=15) 1.88-1.98 mm.

Color. General color of male dark brown (Figs 1, 2). Vertex, frons and genae blackish brown (Figs 1, 5, 6). Eyes grayish black (Figs 1, 2, 5, 6). Antennae pale brown (Figs 1, 2, 5, 6). Pronotum, mesonotum, tegmina and abdomen dark brown (Figs 1, 2, 5); in some specimens the posterior margin of pronotum and scutellum brown. Postclypeus blackish-brown except apex and median carina yellow (Fig. 6). Longitudinal veins of forewing speckled with black brown granules (Figs 1, 2, 19). Legs yellowish brown except fore- and middle coxae brown, apices of spines on tibiae and tarsi of hind legs black (Figs 4, 7). General color of female beige (Fig. 3). Tegmina semitransparent (Fig. 3). Ovipositor brown to blackish brown.

Structure. Vertex at about 1.32 times as broad as long in midline, slightly narrower at apex than at base (about 0.97: 1), anterior margin rounded, slightly projecting in front of eyes, lateral margins concave in dorsal view, submedian carinae originating from near 1/3 base of lateral carinae and feeble at apex (Figs 1, 5). Y-shaped carina with lateral arms faint, basal compartment shallowly concave, wider at base than greatest length (about 1.95:1) (Fig. 5). Fastigium rounded (Fig. 2). Frons longer in midline than maximum width about 1.61:1, widest at level of ocelli, lateral carinae slightly convex medially, median carina feeble at base (Fig. 6). Postclypeus wider at base than frons at apex (about 1.16:1), post- and anteclypeus together approximately 0.89 × the length of frons (Fig. 6). Rostrum almost reaching meso-trochanters. Antennae terete, apex reaching to near the middle of postclypeus, scape longer than wide at apex (about 1.51:1), pedicle nearly twice the length of scape (Fig. 6).

Pronotum in midline slightly shorter than length of vertex (about 0.85:1), lateral carinae slightly curved, not reaching posterior margin of pronotum (Figs 1, 5), Mesonotum medially ca. 1.14 times longer than vertex and pronotum together, lateral carina almost straight, reaching posterior margin, median carina obscure before apex of scutellum (Figs 1, 5). Tegmina almost reaching or slightly surpassing apex of abdomen, longer than widest part about 2.48:1, widest near middle (Figs 1-3, 19). Spination of apex of hind leg 5 (3+2) (tibia), 7(5+2) (basitarsus) and 4 (2nd tarsomere) (Figs 4, 7). Hind tibiae 0.93-1.07 mm long, bearing 2 lateral teeth, post-tibial spur (0.33-0.38 mm) about 0.76 × length of metabasitarsus, without identifiable teeth along posterior margin (Figs 4, 7).

Male genitalia. Pygofer in profile wider ventrally than dorsally, dorsolateral angle roundly produced, caudoventral margin near base with a well-developed, subquadrangular process, reaching the same level as medioventral process in profile (Fig. 9); in posterior view pygofer subquadrate, lateroventral margins excavated, medioventral process simple, spine-like in ventral view (Figs 8, 10, 11). Suspensorium ventrally ring-like, dorsally broad (Fig. 16). Dorsal margin of diaphragm produced, incised and membranous medially, in profile surpassing end of pygofer (Figs 9, 10). Parameres reaching the level of anal segment, sinuate, convergent at bases and then divergent distally, apices narrowed and strongly curved laterad, in posterior view each has a small tooth medially along inner margin (Figs 8, 9, 12, 17). Aedeagus moderate, in profile broadened dorsally in basal 1/3, ventral margin almost straight medially, at apex has a membranous tag on ventral side; in dorsocaudal view the aedeagus armed with approximately ten teeth circling the apical orifice, another bigger tooth, if present, shifted basally on the dorsal side (Figs 12-15). Male anal segment collar-shaped, laterocaudal margin with a long spinous process, overlapped near bases (Figs 8, 9, 12, 18).

Species examined.

Holotype. ♂ (brachypterous, NWAFU), China, Yunnan Province, Weixi County, 13-VIII-2010, coll. Meng Zhang. Paratypes. 15♂♂, 15♀♀ (brachypterous, NWAFU), same data as holotype.

Etymology.

This specific name alludes to the two overlapped processes near bases of the anal segment.

Host plant.

Unknown.

Discussion.

Mestus cruciatus sp. n. differs from Mestus tungpuensis Yang in having the caudoventral protrusion of pygofer near base well developed, extending to the same level as apex of medioventral process in profile; the aedeagus broadened dorsally in basal 1/3, ventral margin in profile almost straight medially. It differs from Mestus morio Motschulsky in having the medioventral process of pygofer simple, not widening in basal third; the inner margin of parameres each with tooth medially in posterior view. Furthermore, the new species differs from both species in having the lateroventral processes of male anal segment overlapped near bases.

Distribution.

Yunnan Province (in southwest China).