Odour‐mediated host preference of Culex quinquefasciatus in Tanzania

Field experiments to determine the host preference of Culex quinquefasciatus Say (Diptera: Culicidae) between man, calf and goat, were conducted in Muheza, north‐east Tanzania. The responses of the mosquito to the three hosts were also compared to their responses to carbon dioxide. A total of 2565 unfed female mosquitoes were collected, of which Cx quinquefasciatus accounted for 96.6% of the catch. A human‐baited tent caught a larger number of host‐seeking Cx quinquefasciatus than a calf‐baited or goat‐baited tent (P<0.05). The man:calf ratio was 7.8:1 while the man:goat ratio was 10:1. The difference in response to either a calf‐ or goat‐baited tent was not statistically significant (P>0.05). The number of mosquitoes attracted to a human‐baited tent was significantly larger than that attracted to carbon dioxide released at 300 ml min−1. Only 25.3% of the human host attractancy was attributed to carbon dioxide. The number of Cx quinquefasciatus responding to a tent baited with a calf or goat was not significantly different from the number responding to a tent baited with carbon dioxide. It can be concluded that with equal availability of the three vertebrate hosts, Cx quinquefasciatus would respond more to volatile cues from a human host than from either a calf or goat, thereby supporting earlier data about its high degree of anthropophily. The major olfactory cue from a goat or a calf to which this mosquito responds is probably carbon dioxide.