Christya Theobald, 1903

Based on the morphology of An. implexus, subgenus Christya shares a number of features with genus Chagasia, including speckled legs, tarsi with unusually broad pale bands and a simple pupal trumpet, and is easily recognisable by long tufts of narrow scales projecting from the abdominal segments.

ADULTS ‒ Large mosquitoes; vertex of head with relatively long and narrow erect scales, mainly dark, pale anteriorly, patch of mainly decumbent truncated pale scales in front of erect scales; maxillary palpus with pale rings mainly at apices of palpomeres 2‒5, palpus of females with peculiar knotted appearance due to groups of semi-erect scales; scutum with sparse covering of yellowish setae and yellowish piliform scales; meso- and metathoracic pleura with conspicuous dark scale-patches sharply delimited by silvery lines and pale scaling; about 6 lower mesepimeral setae present; wing with variable pale scaling; femora and tibiae speckled, spots sometimes united to form bands; fore- and midtarsomeres 1‒4 narrowly pale basally, tarsomere 5 entirely dark, hindtarsomere 1 narrowly pale apically and with indefinite broken line of pale scales, hindtarsomere 2 pale in distal half or more, hindtarsomeres 3 and 4 usually entirely pale, hindtarsomere 5 entirely dark or more often with apical half or less pale; abdominal segments 1‒7 with prominent posterolateral tufts of long narrow mainly dark scales projecting perpendicular to segments; sterna 1‒7 each with pair of conspicuous round clearly defined pale spots. MALE GENITALIA ‒ Ninth tergal lobes large and broad; gonocoxite with 1 short parabasal seta on a prominent tubercle; claspette bilobed, mesal lobe with stout apical seta and many fine short and longer setae on inner side, lateral lobe with slender club formed of 2 coalesced setae; aedeagus with 4 pairs of simple or simple and serrated leaflets. LARVAE ‒ Seta 1-A large, brush-like; pair of seta 2-C inserted close together, simple or split into 2 or 3 apical branches; seta 3-C multi-branched, nearly as long as 2-C; seta 3-T and seta 1-I,II,VII multi-branched, not palmate, branches arranged on both sides of a rachis (pinnate), seta 1-III‒VI palmate with simple transparent lanceolate leaflets (not differentiated as blade with apical filament); seta 6-I‒VI all plumose and borne on tubercle. PUPAE ‒ Cephalothorax with median keel forming conspicuous crest posteriorly; trumpet unusually broad and widely open; seta 1-Pa with 2,3 or more straight branches. See genus Anopheles.