Molecular Characterization and Phylogenetic Analysis of the Pine Tortoise Scale Insect IToumeyella parvicornis/I

Pest molecular characterization is an essential practice to support and complete the classical morphological taxonomy of insects, as well as to provide helpful information that may lead to finding alternative control strategies or detection methods. Molecular biology methods are of great importance, especially for the species whose identification requires highly qualified operators or the support of optical tools for microscopic organisms. This fact is even more amplified if the pest under study is an alien species that can quickly spread into a new area, as in the case of Toumeyella parvicornis (Cockerell) in Italy and Europe at large. This species demonstrates the need for molecular characterization, inspiring the present study. Toumeyella parvicornis (Cockerell) (Hemiptera, Coccidae) is becoming a potential main pest of stone pine plants (Pinus pinea L.), both in urban parks and pinewood forests in Europe. Its recent distribution is a source of concern in several regions of Italy and in France. The early detection of this pest plays a fundamental role to contain its geographical expansion, but its taxonomic identification is still based on laborious observations of the morphological traits. The identification is also complicated by the small size of the pest, which makes the observations possible only through a stereomicroscope. Molecular identification is beneficial for detection, but currently, there is only a single gene sequence available for this pest. This study fills this gap in knowledge by providing the sequences of five different genes (COI, 28S, elongation factor (EF-1α), wingless (wg), and histone H3 (HexA)), together with a phylogenetic analysis carried out among species belonging to Coccidae, one of the most important families of scale insects. The results provide new valuable information about T. parvicornis and may represent useful data for its detection and management practices.