Subgenus Bifidistylus Reinert, Harbach & Kitching, 2009

Type species: 

Aedes lamborni Edwards, 1923.


Subfamily Culicinae, tribe Aedini, genus Aedes. Subgenus Bifidistylus includes only two species. Subgenus abbreviation – Bif.


Subgenus Bifidistylus is named for the distinctive bifurcated gonostylus of the male genitalia. Like most generic-level taxa of tribe Aedini, Bifidistylus is distinguished by a unique combination of characters. The following features are distinctive for the genus. Characters that define the Bifidistylus clade in the phylogenetic analysis of Reinert et al. (2009) are indicated with an asterisk (*).

ADULTS – Occiputand vertex with numerous erect forked scales; eyes above antennal pedicels contiguous or separated by less than diameter of 1 corneal facet; antennal pedicel with several broad scales on mesal surface; clypeus bare; maxillary palpus of females dark-scaled with *pale scales at apex, maxillary palpus of males shorter than proboscis, comprised of 5 palpomeres; scutum with dark and pale falcate scales, prescutellar area with some broad pale scales mesal to setae on each side; acrostichal setae, dorsocentral setae and prescutellar setae well developed; all lobes of scutellum with broad silvery scales; paratergite, upper proepisternum, subspiracular area, postspiracular area, *upper and *lower prealar area, upper and lower areas of mesokatepisternum and upper to middle area of mesepimeron with patches of broad pale scales; *upper prealar area with more than 21 setae; lower mesepimeral setae absent; wing dark-scaled with pale patch at base of costa; upper calypter with numerous setae on margin; ante- and postprocoxal membranes bare; hindfemur, hindtibia and hindtarsomeres 1−4 with pale apical bands, hindtarsomeres *2 and 3,4 with pale basal bands, hindtarsomere 5 pale-scaled; fore-, mid- and *hindungues of females equal, each with 1 tooth, fore- and midungues of males unequal, each with 1 tooth; laterotergite of tergum I with broad pale scales; terga II−VI with basal pale areas. FEMALE GENITALIA – Tergum VIII and sternum VIII wider than long, tergum with numerous broad scales distally and few scattered scales proximally; tergum IX comprised of 2 lateral sclerites separated by mesal membrane, each with 5−13 setae; postgenital lobe with median emargination; lower vaginal sclerite absent; insula tongue-like, without setae; cercus withor without scales; 1 large and 2 slightly smaller spermathecal capsules. MALE GENITALIA – Tergum IX lobes moderately large, each with several setae; sternum IX with 1−4 posteromedian setae; gonocoxite with numerous broad scales on lateral and ventral surfaces; gonostylus attached at apex of gonocoxite, bifurcate near midlength, outer lobe longer with short subapical seta, inner lobe with short flattened gonostylar claw at apex; claspette comprised of small basal plaque bearing few slender setae proximally and several stout setae distally; aedeagus comprised of 2 lateral sclerites, each with few elongate teeth on approximately distal 0.50, *on distal ≤0.55; proctiger without cercal setae. LARVAE – Seta 1-C slender, single; seta 4-C short, with 4 or 5 branches,inserted more or less directly mesal to seta 6-C; seta 5-C with 8 or 9 branches, inserted posteromesal to setae 6,7-C; seta 6-C inserted close to 5-C and mesal and slightly posterior to seta 7-C; 12-C shorter and inserted mesal to seta 13-C; seta 14-C single; seta 19-C absent; setae 1−3-P not inserted on common setal support plate, seta 1-P longer than seta 2-P, seta 2-P longer than seta 3-P; setae 5,6-P long, single, seta 5-P longer than setae 6,7-P; seta 7-P long, with 2 or 3 branches; seta 4-M short, with 2 or 3 branches; setae 5,7-M long, single, seta 5-M longer than seta 7-M; seta 2-T with 4 or 5 branches; seta 6-T single; seta 6-I−VI long, stout, double; seta 7-I long, stout, with 2 or 3 branches; seta 12-I absent; seta 1-VII very long, stout, single, noticeably longer than saddle; setae 2,4-VIII single; comb comprised of numerous scales in triangular patch; siphon moderately long, acus absent; pecten comprised of numerous spines; seta 1-S inserted distal to or within pecten; saddle of segment X incomplete ventrally, acus absent; seta 1-X short, single or double, inserted on saddle; seta 2-X moderately long, with 7−10 branches; seta 3-X long, single; ventral brush (seta 4-X) inserted on grid with both transverse and lateral bars, with 1 (rarely 2) precratal setae, *never 2 or more setae anterior to grid. PUPAE – Tracheoid area of trumpet weakly developed; setae 1-CT and 3-CT similarly developed; setae 4-CT and 5-CT branched and similar in length; setae 10-CT and eta 12-CT branched; seta 11-CT normally single, longer than seta 10-CT and seta 12-CT; seta 3-I long, stout, single, longer than setae 6,7-I; seta 1-II with numerous slender branches; seta 2-II inserted lateral to setae 1,3-II; seta 3-II,III long, stout, single; *seta 5-II longer than seta 3-II; seta 3-III longer than seta 5-III; seta 5-V longer than tergum VI; seta 6-VII inserted posterior and slightly mesal to seta 9-VII, seta 9-VII branched, longer than seta 6-VII; seta 9-VIII with 3−5 branches; paddle rounded apically with midrib extending to near apex, without hair-like marginal spicules; seta 1-Pa short, single or double. See Aedes.

Phylogenetic relationships: 

Although weakly supported, the cladistic analysis of Reinert et al. (2009) placed Bifidistylus in a position basal to a clade comprised of Albuginosus + (Tewarius + (Christophersiomyia + (Huaedes + Leptosomatomyia))), with Polyleptiomyia basal to Bifidistylus. Although the internal branches of the clade were weakly supported and only nine homoplastic characters diagnosed the Bifidistylus branch (the clade was not recovered when the data set was analysed in the study of Wilkerson et al., 2015), the subgenus exhibits clear distinctions from the other generic-level taxa within the clade. Characters of the females and the male and female genitalia that were not included in the analysis support the monophyly of Bifidistylus.

Bionomics and disease relations: 

Larvae principally inhabit rock pools under heavy shade. Females of Bf. lamborni have been collected biting humans in forest.

Species of subgenus Bifidistylus are not medically or economically important to humans.


Cameroon, Democratic Republic of the Congo, Equatorial Guinea, Kenya, Malawi, South Africa, and Zambia.

Principal references: 

Reinert et al., 2009 (as genus, morphology, phylogeny); Reinert, 2010 (as genus, female genitalia); Wilkerson et al., 2015 (phylogeny, classification).

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith