SEXUAL DIMORPHISM IN THE ADULT ANTENNAE OF ANTITROGUS PARVULUS BRITTON AND LEPIDIOTA NEGATORIA BLACKBURN (COLEOPTERA: SCARABAEIDAE: MELOLONTHINAE)

Abstract

Antennae of both sexes of adults of Antitrogus parvulus and Lepidiota negatoria were examined using scanning electron microscopy following critical‐point drying. Males of A. parvulus have 7 large lamellae, the inner surfaces of which have ca 150,000 cup‐shaped placoid sensilla. Females have fewer and smaller lamellae, no placoid sensilla and few basiconic sensilla. Both sexes of L. negatoria have similar 3‐lamellate antennae with placoid sensilla and 2 types of basiconic sensilla. Sensilla differences suggest that male A. parvulus use pheromones to locate distant females, whilst in L. negatoria the antennal sensilla are used to locate host trees and proximate females. Copyright © 1990, Wiley Blackwell. All rights reserved