Subfamily Culicinae, tribe Aedini, genus Aedes. Subgenus Nyctomyia includes two species. Subgenus abbreviation – Nyc.
The following combinations of features distinguish subgenus Nyctomyia from other generic-level taxa of tribe Aedini. Characters that diagnose Nyctomyia in the phylogeny of Reinert et al. (2009) are indicated by an asterisk (*), those that distinguish Nyctomyia from subgenus Borichinda are indicated by a cross (†) and those that distinguish subgenus Nyctomyia from Isoaedes are indicated by a double cross (‡).
ADULTS – ‡Compound eyes narrowly separated; †‡maxillary palpus of males very short, 0.3 length of proboscis, †‡comprised of 4 palpomeres, palpomere 4 vestigial; ‡scutum with some pale scaling, *scales on anterior part of antealar area all pale; †midlobe of scutellum with narrow scales; *postpronotal scales all narrow; ‡postspiracular scales present; ‡subspiracular scales absent; *costal scales of wing all dark; †remigial setae absent; *hindtibia dark-scaled; †foreungues of males both toothed. FEMALE GENITALIA – *Intersegmental membrane between segments VII and VIII short to intermediate in length, segment VIII fully retracted into segment VII; *tergum VIII with setae on distal 0.60 or less, *more than 14 scales present; *sternum VIII with more than 10 scales, covering much of surface; *postgenital lobe ventral index 0.47−1.64; insula without setae. MALE GENITALIA – ‡Sternum IX long, ‡setae present; †‡gonostylus long, enlarged distally; †apex of claspette narrow with few setae; *aedeagus widest in distal third. LARVAE – †Seta 4-C short, 3- or 4-branched; †‡seta 14-C single or double, longer than seta 15-C; †seta 1-P longer than seta 2-P; †‡setae 1,3-P usually double, infrequently triple; ‡seta 5-P double, *as long as or shorter than seta 6-P; ‡seta 5-T small, single; †‡seta 2-I,II large, 2- or 3-branched, †‡seta 2-III–VI small, single or double, inserted anterior to seta 1; †‡seta 11-I large, 2- or 3-branched; *seta 3-II single; †seta 5-II–VI small, usually †‡single; seta 7-II single, short, about half length of seta 6-II; †seta 9-III–VI inserted anterior to and close to seta 7; †seta 10-II–V inserted lateral to setae 11,12; †seta 13-III–V single; †seta 5-VII small, single; ‡comb scales spine-like, in single row; †distal 1 or 2 pecten spines more widely spaced than others; ‡seta 1-X small, single; †‡ventral brush (seta 4-X) with 1 precratal seta, *cratal setae on grid with transverse bars, *seta 4d-X single or double (rarely triple), not plumose. PUPAE – †Seta 7-CT longer than seta 6-CT; ‡seta 3-III single; ‡seta 6-III single or double; †seta 6-VII inserted posteromesal to seta 9; †seta 9-IV–VI inserted posterior to seta 8, †‡seta 9-VII single; †‡apex of paddle slightly produced. See Aedes.
Based on the inclusion of morphological data for Nyctomyia in the parsimony analysis of Reinert et al. (2009), this subgenus appears to be more closely related to subgenera Borichinda and Isoaedes than to other generic-level taxa of tribe Aedini (Harbach et al., 2013). The addition of Nyctomyia resulted in its interposition on a separate branch between Isoaedes and Borichinda with an almost equal division of the characters that supported this branch on either side of the node leading to Nyctomyia, yielding the following branching pattern: (Skusea (Indusius, Cancraedes)) (Fredwardsius (Isoaedes (Nyctomyia (Borichinda ((Diceromyia, Ayurakitia) (Dendroskusea, remainder of the Stegomyia-group)))))). In the absence of Isoaedes, Nyctomyia was recovered as the sister of Borichinda in the maximum likelihood phylogeny of Soghigian et al. (2017) based on molecular markers.
Species of subgenus Nyctomyia are cave-dwelling mosquitoes that have only been found and reared from larvae and pupae collected from rimstone pools in caves in southern Thailand. The water in the pools is clear, cold and devoid of vegetation and plant matter. The caves harbour populations of bats that are likely to be the primary source of food for adult females. Females of Ae. pholeocola, however, are known to bite individuals who enter their cavernicolous environment; thus, species of subgenus Nyctomyia could potentially transmit pathogens from bats to humans. Nothing else is known about the biology of the species.
Species of subgenus Nyctomyia are only known from two caves in southern Thailand: Ae. pholeocola from Wat Tham Phanturat in Surat Thani Province and Ae. biunguiculatus from Wat Tham Sumano in Phatthalung Province.