Efficacy of toxic sugar baits against adult cistern-dwelling Anopheles claviger

Sugar baits were used for mosquito control in cisterns at the building complex of Mar Saba Monastery in the Judean Hills, Israel. These cisterns provide fresh water for the monastery and are breeding and resting sites for Anopheles claviger (Meigen). The baits, including sucrose, fruit juice, dye marker and oral insecticide, were presented at the entrance of the cisterns and caused a drastic decline of A. claviger numbers in the neighbourhood. Pre-treatment catches of 16.8 ± 4.0 to 33 ± 8.1 females per trap decreased to between 2.5 ± 1.3 and 0.3 ± 0.6 females per trap six nights after treatment. Numbers of males were initially 9.2 ± 1.7 to 21.0 ± 4.8 specimens per trap and decreased to between 1.0 ± 0.4 and 0.5 ± 0.2 per trap post treatment. In the control area, where baits without toxin were presented in cisterns, there were only small fluctuations in the mosquito population. Non-poisonous bait marked >95% of the mosquitoes exiting from a cistern in the control area. Following treatment, the number of human-landing mosquitoes decreased by more than ten-fold in the experimental area, whilst in the control area there was no significant decrease.