Comparing morphology of Myzus persicae regarding the taxonomic clarification of a subspecies colonising tobacco

Abstract

So far, multivariate analysis has been the go-to method for differentiation between the subspecies Myzus persicae persicae and M. persicae nicotianae. The present study used scanning electron microscopy (SEM) to analyse reared and field-collected individuals of both subspecies. Several characteristics led to subspecies differentiation at the morphometrical and micromorphological levels. The results are compared with earlier studies. Thus, previous differentiation by length was confirmed, which showed that M. persicae nicotianae has a relatively longer processus terminalis and siphunculus. In general, the apterae of M. p. nicotianae are larger, and both adult morphs exhibit longer hind legs than M. p. persicae.Comparing the alatae of M. p. persicae and M. p. nicotianae, only the latter possesses a scabrous cuticle covering the entire dorsal head. In contrast, alatae M. p. persicae exhibit a distal swelling of the siphunculi with a medial constriction. However, adult morphs of M. p. nicotianae bear siphunculi with constriction just beneath the flange. The SEM micromorphological analysis synergistically adds to the commonly used multivariate morphometry. Thus, closely related subspecies can be differentiated at a more detailed morphological level.