Micromorphology of the model species pea aphid Acyrthosiphon pisum (Hemiptera, Aphididae) with special emphasis on the sensilla structure

Abstract

The pea aphid complex [Acyrthosiphon pisum (Harris 1776)] (Hemiptera, Aphididae), listed among the 14 aphid species of the greatest economic importance, is a globally distributed key pest of pulse crops. Since the pea aphid is a well-studied model organism, an enormous amount of literature has been published about this species. However, comprehensive morphological analyses using scanning electron microscopy (SEM), focused on all body parts of adult viviparous and sexual generations of A. pisum, are lacking. Thus, we present the first detailed morphological description of all body parts of adult wingless and winged viviparous females (parthenogenetic generation) as well as oviparous females, winged and wingless males (sexual generation), representing the most common A. pisum pea biotype. In particular, the sensilla of the body surface, antennae, mouthparts, legs and male genitalia are mapped by the high-resolution scanning electron microscope. The morphological diversity of sensilla is discussed in the context of their function and the biology of aphids.