Sampling gravid Culex quinquefasciatus (Diptera : Culicidae) in Tanzania with traps baited with synthetic oviposition pheromone and grass infusions

The effectiveness of traps baited with (5R,6S)-6-acetoxy-5-hexadecanolide ( the synthetic oviposition pheromone) and grass infusions in sampling a popu lation of gravid Culex quinquefasciatus Say was conducted in Muheza, Northe ast Tanzania. A counterflow geometry (CFG) trap baited with pheromone and s et outdoors, adjacent to a pit latrine building, collected more gravid Cx. quinquefasciatus than a CDC trap baited with pheromone and operated without light. Inside pit latrine buildings, significantly more gravid Cx. quingue fasciatus were collected in a CFG trap-baited with pheromone or grass infus ion than in traps baited with tap water. CFG traps baited with either grass infusion or pheromone and set outdoors, away from known breeding sites, ca ught significantly more gravid Cx. quinquefasciatus than traps baited with tap water. CFG traps baited with pheromone + grass infusion caught signific antly more gravid Cx. quinquefasciatus than CFG traps baited with either gr ass infusion or pheromone. In both cases, the proportion of gravid mosquito es increased as traps were moved away from a natural emergence site. More g ravid Cx. quinquefasciatus were collected in a pheromone-baited CFG trap th an were egg rafts deposited in ajar with pheromonetreated water. It is conc luded that CFG traps baited with oviposition attractants can be used effect ively to sample gravid Cx. quinquefasciatus.