The ability of Rhodnius prolixus (Hemiptera; Reduviidae) to approach a thermal source solely by its infrared radiation.

The ability of the haematophagous bug Rhodnius prolixus to approach a pure IR source only by its long-wave infrared radiation (IR) was investigated. To exclude any heated air from reaching the bug a cooled IR-transmitting window was placed between the IR-source (a Peltierelement heated to 35 degrees C) and the bug. Starved bugs were tested under invisible short-wave IR illumination (lambda<1 µm) in order to exclude also any visual cues. The number of bugs approaching the IR-source was significantly increased compared to the controls in which the IR-source was turned off (chi(2)-test, P<0.01). Our results show that Rhodnius prolixus can use infrared stimuli to find a host.