Wings as Part of the Sensory System in the Aphid Subfamily Eriosomatinae s. lat. (Insecta, Hemiptera).

Wings are a crucial evolutionary trait of insects and constitute an important part of their sensory system. Phloem-feeding aphids specialising in particular host plant species require an efficient sensory system and locomotive abilities to find an appropriate plant to complete the life cycle. Wings (in winged morphs) play a crucial role in this dispersal, but the sensory part of their structure is neglected. Here, we review campaniform sensilla, responsible for sensing the mechanical deformations of wings, in the aphid subfamily Eriosomatinae, where many species are host-alternating, which requires distant flights. Based on light and scanning electron microscopy, we illustrate sensilla and their arrangement on wings in 10 species. We also provide a broader sensory background by correlating their number with other important olfactory and campaniform sensilla of the antennae and legs. We find a strong relation of forewing sensilla with olfactory receptors on antennae, but their number is specific for particular morphs, depending on the required flight effort, led by the abundance of the host plant. Morphs migrating to less abundant host have 1.15 to 1.77 more campaniform sensilla per 1 mm of forewing length than morphs migrating to more abundant host. Aphids reveal a relatively high number of sensilla on the distal part of the forewings, showing their importance for effective sensing the deformation of wing.