Aedes alternans (Westwood, 1835), original combination: Culex alternans.
Subfamily Culicinae, tribe Aedini, genus Aedes. Subgenus Mucidus includes 59 species, one represented by two subspecies, divided between two species groups, the Mucidus and Pardomyia Groups. Subgenus abbreviation – Muc.
ADULTS – Large mosquitoes; eyes narrowly separated above antennae; frons with scales; decumbent scales on vertex broad and narrow or all narrow, erect scales numerous; antenna slightly shorter than proboscis; maxillary palpus of females 0.25–0.6 length of proboscis, palpomere 5 large; maxillary palpus of males longer than proboscis, palpomeres 4 and 5 subequal; scutal scales narrow, acrostichal and dorsocentral setae present; scutellum with narrow scales; paratergite with or without scales; postpronotal setae numerous; pleural scaling varied, pleural setae numerous, mesepimeron with anterior median setae; legs with conspicuous ornamentation, tarsi banded, ungues of females toothed on at least foreleg and midleg; males with ungues of foreleg and midleg enlarged, teeth varied; wing membrane darkly pigmented at base of Rs, basal segment of M3+4 and around radiomedial crossvein; alula with complete marginal fringe; scaling of tergum I and laterotergite restricted. FEMALE GENITALIA – Segment VIII completely retracted or protruding for 0.5 or more of its length from segment VII; cercus long, slender; one large and 2 smaller spermathecae. MALE GENITALIA – Segment VIII strongly developed, narrowed at base; tergum IX poorly sclerotised, lobes poorly differentiated but with setae; sternum IX large, with group of setae; gonocoxite with distinct basomesal lobe bearing differentiated setae; gonostylus long, simple, with subapical setae; gonostylar claw slender, attached at apex of gonostylus; aedeagus simple, trough-like; claspette strongly differentiated, with slender stem andan apical seta in form of long appendage; proctiger strongly developed, withstrong basolateral sclerotisation; paraproct with strong apical spine; cercal setae present. LARVAE – Median labral plate very wide and large; mouthparts modified for predation, filaments of each lateral palatal brush in compact group on prominent lateral lobe, filaments (25–30) rather short, curved and with strongapical pectination; mandibular teeth very large and strong; seta 1-C strongly displaced laterad; setae 0,3-C close together, 4-C cephalad of antenna1 base, long; setae 5–7-C far caudad of antenna1 base, 6-C short, 5,7-C long; setae 12–15-C strongly displaced cephalad; seta 13-P absent; seta 12-I present; 6-I–VI long, usually single or double; 7-I,II large, multiple branched; 1-III–V strongly developed; setae 1,2-VIII on small common basal plate; comb scales fringed, in patch; siphon long, acus strongly developed, attached; segment X elongate; saddle incomplete, marginal spicules present or absent, acus absent; seta 1-X single, inserted on saddle; setae 2,3-X single; ventral brush (seta 4-X) strongly developed, with 13 or 14 pairs of setae extending nearly entire length of segment, more caudal setae on a grid or boss. PUPAE – Trumpet elongate, tracheoid strongly developed; setae 2,3-CTclosely approximated, removed from caudal margin of sclerite; setae 2,3-I approximated; seta 1-II single, inserted very close to midline; seta 9-VI small, similar to setae 9-II–V; seta 2-VI,VII laterad of seta 1. See Aedes.
The phylogenetic studies of Reinert et al. (2008, 2009) based on cladistics analyses of morphological data corroborate the monophyly subgenus Mucidus (as genus), its distinction from subgenera Aedes and Ochlerotatus, and the recognition of the Mucidus and Pardomyia Groups (as subgenera Mucidus and Pardomyia, respectively). The results of the their studies indicate that genus Psorophora is the most ancestral clade of Aedini and the sister to Mucidus + all other aedine taxa. Mucidus was unassociated with other generic-level taxa in the phylogeny of Wilkerson et al. (2015). In contrast to the results of Reinert et al., two species of the Mucidus Group were recovered as the sister to a clade comprised of species of Haemagogus, Howardina, Macleaya and Ochlerotatus in the maximum likelihood phylogeny of Soghigian et al. (2017) based on seven molecular markers.
Larvae of species of subgenus Mucidus are found in temporary ground pools of various types, and are predaceous on other mosquito larvae. Females of several species of the Mucidus Group are reported to attack humans at least occasionally, chiefly at night. Females carry the abdomen curved forward beneath the thorax. Because of a lack of succession of generations in larval habitats, Hopkins (1952) suggested that females deposit eggs while flying, and the eggs are resistant to desiccation. Mucidus species primarily inhabit fresh water, but larvae of Ae. alternans are said to develop successfully in saline marshes (Knight, 1947) and Ae. aurantius chrysogaster has been found in highly polluted water (Bick, 1951).
Species of subgenus Mucidus are not of medical and economic importance to humans.
Species of subgenus Mucidus are found in the Afrotropical, Australasian and Oriental Regions.
Tyson, 1970 (taxonomy); Reinert et al., 2004, 2006, 2008, 2009 (as genus, morphology, phylogeny); Reinert, 2006 (as genus, taxonomy); Rattanarithikul et al., 2010 (as genus, Thailand, keys, bionomics); Wilkerson et al., 2015 (phylogeny, classification); Soghigian et al., 2017 (phylogenetic relationships).