The Infrared Receptive Fields of Melanophila Acuminata (Coleoptera: Buprestidae)

Receptive fields of the infrared receptors located in sensory pits adjacent to the mesocoxal cavities of Melanophila acuminata were measured using a goniometric apparatus and plotted on a Mollweide homolographic projection. The receptive fields extend mainly in a lateral and ventral direction. The total receptive area in units of solid angle is 5.80 steradians but the simultaneous field of perception of infrared radiation of all the sensilla in a pit is only 0.42 steradian. Based on these findings and on other evidence we believe that the infrared-sensitive sensilla function during flight and are used by these beetles for detecting point sources of heat, such as forest fires, from long distances.