15 

 Emanations from animals including man . The use of l-octen-3-ol and its 



effect on some species of mosquito has been examined [1 1,20-24]. Octenol is present 



in ox breath and has been found to be an attractant for the tsetse fly. Although the 



response to octenol alone is not as great as the response to carbon dioxide, 



synergism is present when both are employed for attraction in some species of 



mosquitoes [20-24]. Lactic acid and octenol provided an additive effect for Ae. 



taeniorhynchus [11]. An interesting note is that Kline suspects that octenol will not 



activate flight, nor directionally alight the mosquito to the host at short range; 



instead, octenol is suggested to play a role in upwind flight, involving odor plumes, 



towards the host [11]. 



Lactic acid, obtained from acetone washings of human skin, was first 

 identified as a chemical attractant XoAe. aegypti by Acree et al. in 1968 [28]. Studies 

 of structurally similar compounds to lactic acid have produced mixed results [19]: 

 to-date, lactic acid is the only widely accepted attractant iorAe. aegypti. In females, 

 the response to lactic acid has been found to elicit response from the grooved peg 

 sensilla [12]. Attributed to the grooved pegs are neurons which either give an 

 excitatory or an inhibitory response to lactic acid. Studies comparing mosquito 

 attraction between host-seeking and non-host-seeking mosquitoes have demonstrated 

 differing sensitivities to lactic acid. After a blood meal, a mosquito which is non- 

 host-seeking has a suppressed excitatory neuron response [12]. 



Emanations from plants . Almost all mosquito species examined take sugar 

 meals [13]. Nectar feeding is necessary for survival in both sexes. If any differences 



