Infrared receptors in pyrophilous insects

Abstract

So far, infrared (IR) receptors in insects have only been found in representatives of three beetle genera and one hemipteran genus, all of which fy to forest fres and are therefore referred to as pyrophilous. On freshly burned areas, the IR receptors serve as early warning systems that can be used to avoid landing on a hot spot. However, there is evidence in jewel beetles of the genus Melanophila, that the IR receptors may also serve to locate forest fres from greater distances. As the pyrophilous lifestyle has evolved independently in the four genera, no “standard IR receptor” exists. Mechanosensory-based, so-called photomechanic IR receptors have evolved in Melanophila beetles and pyrophilous Aradus bark bugs. In the Australian fre beetle Merimna atrata and in the small ash beetle Acanthocnemus nigricans, on the other hand, thermal IR receptors are found, in which an increase in temperature caused by IR absorption is measured.