Genus Alanstonea Mattingly, 1960
Alanstonea treubi (de Meijere, 1910), original combination: Scutomyia treubi.
Subfamily Culicinae, tribe Aedini. Alanstonea includes two species. Genus abbreviation – As.
The adults of Alanstonea generally resemble the adults of genus Armigeres in size and coloration, in having the proboscis laterally compressed and curved downward, and in the absence of dorsocentral setae. They differ from those of Armigeres in the absence of a lower mesepimeral seta and features of the male genitalia. The differences are more striking in the immature stages. The paddles of pupae lack a midrib and a marginal fringe, which are present in Armigeres. The siphon of Alanstonea larvae is narrow and bears a pecten and the anal papillae are narrow and pointed whereas the pecten is absent, the siphon very broad and stumpy and the anal papillae are broad with rounded apices in Armigeres. The similarity of Alanstonea with Stegomyia lies mainly with the male genitalia and with several larval characters. However, Alanstonea adults differ from Stegomyia adults in having a curved proboscis and legs without white bands. Larvae are distinguished from other Aedini by the combination of single setae 2- and 3-X and the absence of a grid or boss at the base of the ventral brush. Other characteristics include the following: ADULTS ‒ Pedicel of antenna with scales on lateral surface; maxillary palpus of females shorter than 0.25 length of the proboscis; maxillary palpus of males longer than the proboscis, slender, almost bare, palpomere 5 no thicker than palpomere 4; paratergite with numerous scales; mesopleuron with hypostigmal and upper and lower mesokatepisternal scales patches more or less contiguous; upper mesokatepisternal setae absent; postspiracular area with few or no scales; mesepimeral scale patch extends into the upper mesepimeral setae; anteprocoxal scales present; alula of wing with broad scales, dorsal tertiary fringe scales absent; hindcoxa more or less in line with dorsal margin of mesomeron; fore- and midungues of males simple; insula of females without setae. MALE GENITALIA ‒ Gonocoxite with scales; gonostylus with single apical claw; basal mesal lobe with numerous relatively short stout setae; aedeagus with apices of lateral plates fused. LARVAE ‒ Setae 4–6-C inserted well anterior to seta 7-C; setae 1- and 2-P on common tubercle; seta 1-I reduced, with 2 or 3 main branches and some secondary branching or feathering; seta 7-I‒V small and inconspicuous; seta1-S inserted near apex of siphon; seta 8-S very long; ventral brush (seta 4-X) comprised of 8 or 9 setae that are all or mostly single. PUPAE ‒ Trumpet without tracheoid; seta 6-I shorter than seta 7-I; seta 9-VII,VIII very long; paddles very small, shorter than seta 9-VIII, sub-triangular; seta 1-Pa well developed. See Aedini.
The past inclusion of species of Alanstonea in genera Armigeres and Stegomyia (as a subgenus of Aedes) suggested affinities with these two taxa. However, in the comprehensive cladistic study of tribe Aedini conducted by Reinert et al. (2009), Alanstonea and the Afrotropical Pseudarmigeres were recovered as sister taxa in a clade that comprised Petermattinglyius + (Alanstonea + Pseudarmigeres) + Heizmannia)), and this clade in a sister relationship to a clade comprised of Lorrainea + (((Udaya + (Belkinius + Zeugnomyia)) + (Eretmapodites + Armigeres)). A clade comprising Armigeres + (Alanstonea + Eretmapodites) was recovered in the phylogenetic analyses of Wilkerson et al. (2015). Additional study is needed to further resolve these relationships.
The immature stages are found in Nepenthes pitcher plants. The larvae are carnivorous and feed on other mosquito larvae (Mogi & Yong, 1992; Mogi & Chan, 1996). Nothing is known about the biology of the adults.
Alanstonea species are of no medical or economical importance.
Southeast Asia: recorded from Brunei, Indonesia (Java, Sumatra), Malaysia (Peninsular, Sarawak) and Thailand.
Mattingly, 1960 (subgenus of Aedes); Mattingly, 1971 (eggs); Ramalingam & Ramakrishnan, 1971; Reinert, 2000 (female genitalia); Reinert et al., 2004 (generic status, morphology, phylogeny); Reinert et al., 2009 (morphology, phylogeny); Rattanarithikul et al., 2010 (Thailand, keys, bionomics); Wilkerson et al., 2015 (as subgenus of Aedes, phylogeny).
