Heliographic signalling in Haploglenius Burmeister, 1839 (Neuroptera Ascalaphidae)

The males of the ascalaphid genus Haploglenius are equipped with a movable pronotal flap, covering a white thoracic membrane, whose function remains poorly known. Few recent original observations, conducted on undisturbed specimens in their natural environment, suggest that this structure is part of a complex visual communication system based on intermittently showing the bright, reflecting, thoracic white area on a dark background. This behaviour is probably associated with courtship.