NEOTROPICAL REGION
Generic abbreviation: Ch.
Type species: Chagasia neivae Cruz (subjective synonym of Chagasia fajardi (Lutz 1904))
Etymology: Evandro Chagas
The Neotropical genus Chagasia comprises only five described species: Ch. ablusa Harbach, Ch. bathana (Dyar), Ch. bonneae Root, Ch. fajardi (Lutz) and Ch. rozeboomi Causey, Deane & Deane. Chagasia bathana extends from southern Mexico south through central America to Ecuador, Colombia and Venezuela; all other species are restricted to South America. Recently a new species (Chagasia nr. fajardi) was discovered by WRBU in collections from the Amazonian forest of eastern Ecuador. Chagasia species most closely ressemble the subfamily Anophelinae, but also bear some key characters mostly commonly associated with the subfamily Culicinae, including a tri-lobed scutellum with setae in three groups, parallel resting stance, postpronotal setae, and an arched scutum. Phylogenetic studies suggest that Chagasia species form a monophyletic lineage basal to other Anophelinae, the basal ancestral lineage within Culicidae and the possible New World origin of all mosquitoes. Chagasia bathana has three pairs of autosomes and a pair of sex chromosomes (2n = 8), in comparison to the 2n = 6 reported in all other mosquitoes. Midges of the family Chaoboridae, once regarded as a subfamily within Culicidae, also share the same chromosomal arrangement (2n = 8).
DIAGNOSTIC CHARACTERS (Click photos to view; mouse over and click large photo to zoom in.)
ADULT (illustrated): Thorax: Scutellum slightly tri-lobed with setae in three groups. Wing: Dark-scaled, or with dark and pale scales, not forming distinct spots. Abdomen: With plentiful setae, but almost devoid of scales.
LARVA (not illustrated): Head: Setae 2,4,6-C with very long stems ending in multiple long branches. Abdomen: Seta 1-III–V palmate with distinctive spatulate leaflets. Terminal segments: Anterior spiracular lobe with elongate median process; spiracular median plate with a fringe of long spicules laterally.
TAXONOMIC KEYS
Lane 1953
Harbach & Howard 2009
WRBU – Genera – Global – Larva
WRBU – Genera – Neotropical – Adult
WRBU – Genera – Neotropical – Larva
Exemplar DNA sequences
Ch. bathana COI (KX420410-14)
Ch. bonneae COI (KF671005-11, KX420415)
Ch. nr. fajardi COI (KF671012-13)
BIONOMICS
Immatures
Immatures of the genus Chagasia are found in hiding in dead leaves or floating debris in the slow-flowing grassy margins of shady forest streams. They are often recovered in the slow-flowing waters caught around tree roots, or in clear rock pools in stream basins.
Adults
Members of the genus Chagasia are true forest species and adults often rest in the vegetation close to the immature sites or in the humidity of the heavily shaded forest canopy. Female Chagasia species bite day and night deep in the forest, where they seldom encounter man. Although anthropophagic under forced laboratory conditions, Chagasia are essentially zoophilic.
*Associated pathogens: This list reports bacteria, viruses, and parasites recovered from, or experimentally passed through this species, and does not imply field vector status.
IMPORTANT REFERENCES (full citations below)
Cruz 1906: 199 (F)
Lane 1953: 138 (M*, F, L*, P*, E*; keys, taxonomy, bionomics)
Kreutzer 1978 (chromosome number)
Harbach & Howard 2009 (M*, F*, P*, L*; keys, taxonomic review)
Beltrán-Aguilar et al. 2011 (M gen*, F*, P*, L*; bionomics, taxonomy, distribution; Mexico)
VALID SUBGENERA
None
CURRENT GENERIC SYNONYMS
None
CITED REFERENCES
Beltrán-Aguilar, A., Ibañez-Bernal, S., Mendoza-Palmero, F., Sandoval-Ruiz, C.A., & Hernández-Xoliot, R.A. (2011). Taxonomy and distribution of the anopheline mosquitoes in the state of Veracruz, Mexico (Diptera: Culicidae, Anophelinae). Acta Zoologica Mexicana Nueva Serie, 27(3), 601–755.
Cruz, O.G. (1906). Um novo genero da sub-familia Anophelina. Brasil-Médico, 20(20), 199–200.
Kreutzer, R.D. (1978). A mosquito with eight chromosomes: Chagasia bathana Dyar. Mosquito News, 38(4), 554–558.
Leví-Castillo, R. (1953g). Aedes Garcíai n. sp., un aedino nuevo para la fauna ecuatoriana. Lanesia, nuevo subgenero de Aedes. Revista Ecuatoriana de Entomología y Parasitologia, 1(3), 101–106.
Harbach, R.E., & Howard, T. M. (2009). Review of the genus Chagasia (Diptera: Culicidae: Anophelinae). Zootaxa, 2210, 1–25.
CITE THIS PAGE
Walter Reed Biosystematics Unit (Year). Chagasia genus page. Walter Reed Biosystematics Unit Website, http://wrbu.si.edu/vectorspecies/genera/chagasia, accessed on [date (e.g. 03 February 2020) when you last viewed the site].
