The role of proboscis of the malaria vector mosquito Anopheles stephensi in host-seeking behavior

Background. the proboscis is an essential head appendage in insects that processes gustatory code during food intake,particularly useful considering that blood-sucking arthropods routinely reach vessels under the host skin using this proboscis as a probe. results. here,using an automated device able to quantify co2-activated thermo (35°c)-sensing behavior of the malaria vector anopheles stephensi,we uncovered that the protruding proboscis of mosquitoes contributes unexpectedly to host identification from a distance. ablation experiments indicated that not only antennae and maxillary palps,but also proboscis were required for the identification of pseudo-thermo targets. furthermore,the function of the proboscis during this behavior can be segregated from co2 detection required to evoke mosquito activation,suggesting that the proboscis of mosquitoes divide the proboscis into a thermo-antenna in addition to a thermo-probe. conclusions. our findings support an emerging view with a possible role of proboscis as important equipment during host-seeking,and give us an insight into how these appendages likely evolved from a common origin in order to function as antenna organs. © 2011 maekawa et al; licensee biomed central ltd.