Ouedraogo_2005_Bull.Soc.Pathol.Exot_98_406

This study conducted from 1999 to 2000 in the suburbs of Bobo Dioulasso a town in the South of Burkina, aimed at investigating the susceptibility of the local population of Culex quinquefasciatus to various insecticides and proposing alternative strategies allowing a better management of insecticide resistance in the field. Eggs of C. quinquefasciatus were first collected in stagnant waste water places. The larvae were reared to early 4rth instar and tested by larval bioassays to determine the LC50/95 and the resistance ratios (RR50 and RR95) as well as their confidence intervals. A susceptible reference Strain "Slab" was used as control. Resistance was found to DDT and pyrethroids, but reduced susceptibility was found for carbamates, organophosphorates, phenyl pyrazole and in a less extend to Bacillus sphaericus. Resistance to pyrethroides is quite alarming since these insecticides are mainly used for bed net impregnation for the Roll Back malaria programme implemented in Africa. The high levels of insecticide resistance in C. quinquefasciatus suggest that alternative strategies have to be implemented to minimize the pressure of selection on resistant genes. The use of bio-larvicides (Bacillus sphaericus) alone or in rotation with different compounds may be a promising strategy for controlling C. quinquefasciatus in Bobo Dioulasso.