Ultrastructure of Antennal Sensilla of a Prionine Longhorn Beetle, Prionoplus reticularis (White)

Abstract

Antennal sensilla are fundamental to an insects sensory perception of its environment. In species where one sex produces pheromones for attracting mates, we can predict antennal and sensilla morphology to be sexually dimorphic. Prionoplus reticularis White (Prioninae; Cerambycidae; Coleoptera) is a large longhorn beetle exhibiting a scramble competition polygyny mating system with sexual dimorphism present in antennae length, suggesting chemical cues are of importance in male mate searching. The present study aims to investigate the antennal ultrastructure morphology and sexual dimorphism in this species using scanning electron microscopy. Various sensilla were identified only in males: sensilla filiformia, sensilla auricillica, wall pore hairs, and distal sensilla chaetica. These sensilla are known to have chemosensory and mechanosensory functions in other insect groups, suggesting these sensory organs play an important role in male mating strategies.