Mark-release-recapture experiments with Anopheles gambiae s.l. in Banambani Village, Mali, to determine population size and structure

摘要

Mark-release-recapture experiments with A. gambiae s.l. were performed during the wet seasons of 1993 and 1994 in Banambani, Mali. All recaptured mosquitoes were identified to species by PCR analysis and, when possible, by chromosomal analysis to chromosomal form. Two species of the A. gambiae complex were present: A. gambiae s.s. and A. arabiensis; their ratio differed greatly from 1 year to the next. 3 chromosomal forms of A. gambiae s.s. were found - Bamako, Savanna and Mopti. The drier 1993 wascharacterized by a high frequency of A. arabiensis and of the Mopti chromosomal forms of A. gambiae s.s. These trends were consistent with large-scale geographical patterns of abundance along a precipitation gradient. No difference in dispersal was observed between the 2 species, nor among the chromosomal forms of A. gambiae s.s. Therefore, in this situation at least, it is reasonable to group such data on the A. gambiae complex as a whole for analysis. Population size of A. gambiae s.l. females in thevillage was estimated to be 9000-11 000 in 1993 and 28 000 in 1994. The corresponding numbers were somewhat higher when independently-derived values of daily survival were used. These were consistent with estimates of effective population size obtainedfrom patterns of gene frequency change.