Infrared Sensors Base on Biopolymers: the Unique Infrared Receptors in "Fire-Loving" Beetles

Helmut Schmitz

Institut für Zoologie der Universität Bonn, Poppelsdorfer Schloss, D-51115 Bonn, Germany




Certain species of buprestid beetles show a so-called pyrophilous behaviour; i.e. the beetles approach forest fires. Immediately after the blaze, the pyrophilous beetles invade the freshly burnt area where they search for food (e.g. scorched small animals) and start reproduction. Two genera of jewel beetles (family Buprestidae) can be classified as pyrophilous: About a dozen species of the genus Melanophila which are distributed nearly all over the world except Australia and the Australian "fire-beetle" Merimna atrata which is endemic to Australia. The reason for the pyrophilous behaviour is that the wood-boring larvae of Melanophila and Merimna can only develop in the wood of burnt trees. As a morphological speciality both pyrophilous buprestid genera are equipped with IR receptors. Another pyrophilous beetle can be found in Australia: the "little ash beetle" Acanthocnemus nigricans (family Acanthocnemidae). This inconspicuous beetle is only 4 mm long and highly attracted by hot ash. However, its biology is unknown. Obviously, Acanthocnemus also depends on fires for its reproduction and is equipped with a pair of sophisticated IR receptors. The talk deals with structure and function of the three biological IR receptors and presents a technical sensor prototype derived from the IR receptor of Melanophila beetles.