title: Aestivation of the African malaria mosquito, Anopheles gambiae in the Sahel.
abstract: The African malaria mosquito, Anopheles gambiae, inhabits diverse environments including dry savannas, where surface waters required for larval development are absent for 4-8 months per year. Under such conditions, An. gambiae virtually disappears. Whether populations survive the long dry season by aestivation (a dormant state promoting extended longevity during the summer) or are reestablished by migrants from distant locations where larval sites persist has remained an enigma for over 60 years. Resolving this question is important, because fragile dry season populations may be more susceptible to control. Here, we show unequivocally that An. gambiae aestivates based on a demographic study and a mark release-recapture experiment spanning the period from the end of one wet season to the beginning of the next. During the dry season, An. gambiae was barely detectable in Sahelian villages of Mali. Five days after the first rain, before a new generation of adults could be produced, mosquito abundance surged 10-fold, implying that most mosquitoes were concealed locally until the rain. Four days after the first rain, a marked female An. gambiae s.s. was recaptured. Initially captured, marked, and released at the end of the previous wet season, she has survived the 7-month-long dry season. These results provide evidence that An. gambiae persists throughout the dry season by aestivation and open new questions for mosquito and parasite research. Improved malaria control by targeting aestivating mosquitoes using existing or novel strategies may be possible.
authors.affiliation: Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA. tlehmann@niaid.nih.gov
authors.forename: Tovi
authors.initials: T
authors.lastname: Lehmann
authors.forename: Adama
authors.initials: A
authors.lastname: Dao
authors.forename: Alpha Seydou
authors.initials: AS
authors.lastname: Yaro
authors.forename: Abdoulaye
authors.initials: A
authors.lastname: Adamou
authors.forename: Yaya
authors.initials: Y
authors.lastname: Kassogue
authors.forename: Moussa
authors.initials: M
authors.lastname: Diallo
authors.forename: Traoré
authors.initials: T
authors.lastname: Sékou
authors.forename: Cecilia
authors.initials: C
authors.lastname: Coscaron-Arias
mesh_terms: D000818:Animals; D000852:Anopheles / Q000254:growth & development*; D005260:Female; D007814:Larva / Q000254:growth & development*; D011891:Rain; D012621:Seasons
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