title: Larval habitat diversity and ecology of anopheline larvae in Eritrea.
abstract: Studies on the spatial distribution of anopheline mosquito larvae were conducted in 302 villages over two transmission seasons in Eritrea. Additional longitudinal studies were also conducted at eight villages over a 24-mo period to determine the seasonal variation in anopheline larval densities. Eight anopheline species were identified with Anopheles arabiensis predominating in most of the habitats. Other species collected included: An. cinereus, An. pretoriensis, An. d'thali, An. funestus, An. squamosus, An. adenensis, and An. demeilloni. An. arabiensis was found in five of the six aquatic habitats found positive for anopheline larvae during the survey. Anopheles larvae were sampled predominantly from stream edges and streambed pools, with samples from this habitat type representing 91.2% (n = 9481) of the total anopheline larval collection in the spatial distribution survey. Other important anopheline habitats included rain pools, ponds, dams, swamps, and drainage channels at communal water supply points. Anopheline larvae were abundant in habitats that were shallow, slow flowing and had clear water. The presence of vegetation, intensity of shade, and permanence of aquatic habitats were not significant determinants of larval distribution and abundance. Larval density was positively correlated with water temperature. Larval abundance increased during the wet season and decreased in the dry season but the timing of peak densities was variable among habitat types and zones. Anopheline larvae were collected all year round with the dry season larval production restricted mainly to artificial aquatic habitats such as drainage channels at communal water supply points. This study provides important information on seasonal patterns of anopheline larval production and larval habitat diversity on a countrywide scale that will be useful in guiding larval control operations in Eritrea.
authors.affiliation: National Malaria Control Program, Division of Communicable Diseases Control, Ministry of Health, P. O. Box 212 Asmara, Eritrea.
authors.forename: Josephat
authors.initials: J
authors.lastname: Shililu
authors.forename: Tewolde
authors.initials: T
authors.lastname: Ghebremeskel
authors.forename: Fessahaye
authors.initials: F
authors.lastname: Seulu
authors.forename: Solomon
authors.initials: S
authors.lastname: Mengistu
authors.forename: Helen
authors.initials: H
authors.lastname: Fekadu
authors.forename: Mehari
authors.initials: M
authors.lastname: Zerom
authors.forename: Asmelash
authors.initials: A
authors.lastname: Ghebregziabiher
authors.forename: David
authors.initials: D
authors.lastname: Sintasath
authors.forename: Gustavo
authors.initials: G
authors.lastname: Bretas
authors.forename: Charles
authors.initials: C
authors.lastname: Mbogo
authors.forename: John
authors.initials: J
authors.lastname: Githure
authors.forename: Eugene
authors.initials: E
authors.lastname: Brantly
authors.forename: Robert
authors.initials: R
authors.lastname: Novak
authors.forename: John C
authors.initials: JC
authors.lastname: Beier
mesh_terms: D000818:Animals; D000852:Anopheles / Q000254:growth & development*; D044822:Biodiversity; D017753:Ecosystem; D004777:Environment; D019017:Eritrea; D005618:Fresh Water / Q000469:parasitology*; D005843:Geography; D006801:Humans; D007814:Larva; D008288:Malaria / Q000635:transmission