Morphological differences between nymphal instars and descriptions of the antennal sensory structures of the nymphs and adults of Psylla pyricola Foerster (Homoptera: Psyllidae)

Abstract

Variations in the external appearance of the nymphs and imago of the pear psylla, Psylla pyricola, are described. The antennal flagellum has five types of sensilla: sensilla chaetica, sensilla trichodea, sensilla campaniformia, sensilla basiconica, and sensilla placodea. The sensilla placodes of the nymphal instars have a 'honeycomb' appearance which is replaced by 'flaps' in the adult. There is an increase in the number of sensilla placodea from one in the first nymphal instar to four in the adult.