Nyssorhynchus Blanchard, 1902

Subgenus Nyssorhynchus is most closely related to subgenus Kerteszia. The two subgenera are very similar in overall morphology, but the following features easily distinguish the adults, larvae ana pupae of Nyssorhynchus. The scutum of adults lacks dark longitudinal lines and has scales on the acrostichal and dorsocentral areas in addition to a few scales in patches on the lateral and/or anterior areas. The scutellum has numerous scattered white, yellow or silver scales along the posterior border. The wings differ in having crossveins sc-r and r₁-r_s closer together (distance about 0.30 or less the length of the sector dark spot on the costa and radius-one), no spot of dark scales where the humeral crossvein intersects the radius, the subcosta terminates at the proximal end or the middle of the subcostal pale spot, vein R4+5 is narrowly pale-scaled apically with a corresponding isolated apical pale fringe spot, vein CuA is mostly pale-scaled or equally pale- and dark-scaled without a basal dark spot and the anal vein has three pale-scaled areas setting off two dark areas between the basal and an apical pale spot (a greater amount of dark scaling occurs in species of the Myzorhynchella Section). The gonocoxite, claspette and aedeagus of the male genitalia exhibit a number of distinctions. The gonocoxite has a subapical seta, two subequal accessory setae are inserted before mid-length (about 0.4 from base), the internal seta is as long but much weaker than the accessory setae, and the parabasal seta is shorter than the internal seta (about 0.6 its length). The ventral lobes of the claspette are fused to form a single structure, the dorsal lobes each bear a single group of two or three specialised setae, and the aedeagus is broad and not noticeably tapered (at least in the basal 0.8). Larvae exhibit differential and diagnostic features, which include, but are not limited to, seta 1-A branched and inserted dorsomesally, seta 2-C inserted anterior to seta 3-C, seta 4-C inserted posteromesal to seta 3-C, hypostomal suture well developed (but not reaching the posterior tentorial pit), presence of a sclerotised tubercle at the bases of setae 1,2-P, short seta 4-M (not more than half as long as seta 6-M), strongly plumose setae 8-M,T and 6,7-I,II, palmate or fanlike seta 3-T, multiply branched seta 2-I–IV, presence of seta 14-III, seta 2-IV inserted mesad to seta 4-IV, well developed seta 1-S (with multiple branches) and eight pairs of seta 4-X. Salient features of Nyssorhynchus pupae include a trumpet with a long pinna (more than half as long as the trumpet) and a meatal cleft, seta 9-I more than half the length of seta 6-I, well developed setae 1-I–VII and 5-V–VII (nearly as long or longer than the segment), seta 14-III present, seta 2 on segments IV and V inserted mesad of seta 3, seta 3-VI inserted mesad to or in line with seta 1-VI, seta 10-VI absent, and seta 1-Pa slender, similar to seta 2-Pa or sinuous and apically hooked. See genus Anopheles.