First report of Toumeyella parvicornis (Cockerell) in Europe (Hemiptera: Coccidae).

Toumeyella parvicornis (Cockerell), the Pine tortoise scale, is reported for the first time from Europe. Pre-imaginal instars and adults were observed starting from the fall of 2014 in several municipalities of Campania (Italy). Since the species is recorded as a harmful pest of several pine species in North America and the Caribbean, the presence of this alien insect in Europe is alarming and represents a possible major threat for native pine species and related economic activities. Scale insects are one of the most commonly transported groups of insects in plant trade and at the same time are one of the most successful invasive groups of insects (Pellizzari et al., 2005; Malumphy et al., 2012). Here we report the occurrence of Toumeyella parvicornis (Cockerell), the Pine tortoise scale, in southern Italy infesting Pinus pinea L. in urban environments. Italy is one of the most invaded of European countries by alien insects (Inghilesi et al., 2013) and this new record updates the list of the established Coccoidea in the country to 50 species (Mazzeo et al., 2014). During the last months of 2014, severe infestations of a sap feeding insect, producing huge amount of honeydew with impressive sooty mould development, were observed on stone pines (P. pinea) in Naples and neighboring municipalities (Campania, Italy). Abundant colonies of a soft scale insect were collected in many sampling sites. All slide mounted specimens (i.e., adult females and males, male tests and first-instar nymphs), representative of the collected samples, were ascribed to a species of the genus Toumeyella Cockerell associated with Pinaceae (Hamon & Williams, 1984; Hodgson, 1994; Kondo & Pellizzari, 2011; Miller & Williams, 1995; Sheffer & Williams, 1990), namely T. parvicornis. The genus Toumeyella has a wide distribution in the Nearctic and Neotropical Regions, with most species being described from the USA (Williams & Kondo, 2008). Currently there are 18 named species included in this genus, which are distributed in Brazil (3 spp.), Canada (2 spp.), Colombia (1 sp.), Cuba (2 spp.), Guatemala (1 sp.), Mexico (6 spp.), Puerto Rico (1 sp.), Turks & Caicos Islands (1 sp.), the USA (9 spp.) and Venezuela (1 sp.) (Kondo & González, 2014; Ben-Dov et al., 2015). Four species of Toumeyella live on Pinus spp.: T. parvicornis, T. pini (King), the striped pine scale, T. pinicola Ferris, the irregular pine scale, and T. virginiana Williams & Kosztarab, the Virginia pine scale (Williams & Kondo, 2008). The Pine tortoise scale has two forms, the typical bark form and a leaf form (Hamon & Williams 1984; Kondo & Pellizzari, 2011) (Fig. 1a–c). This species can be easily separated from other congeneric species by the characteristic dorsal bilocular pore clusters present on the adult female, with other minor differences on the antennae, anal plates and spiracular furrows (Fig. 2a–c) (Hamon & Williams, 1984; Williams & Kosztarab, 1972). Toumeyella species can be also distinguished by morphological characters of the first instars (Figs 1d, 2d) and male tests (Miller & Williams, 1990; Sheffer & Williams, 1990). T. parvicornis was originally described from Florida (USA), on Pinus palustris and P. taeda but is now known from Canada, Mexico, and all of the USA and is an important pest of several Pinus species (Clarke, 2013). Recently, T. parvicornis has been accidentally introduced into Puerto Rico (Segarra-Carmona & Cabrera-Asencio, 2010) and Turks and Caicos Islands, where it has become a severe pest of Pinus caribaea (Malumphy et al., 2012). T. parvicornis shows great environmental adaptability and an easy acceptance of new hosts, and this might allow the species to spread quickly into new territories. It is considered a destructive species infesting the most vigorously growing succulent twigs. In the northern parts of its range, the pine tortoise scale has one generation per year whereas four generations are typical for southern Georgia, USA (Clarke, 2013). In Turks and Caicos Islands, where even a fifth generation is possible, the impact of T. parvicornis has been severe. As reported by Malumphy et al. (2012), some of the infested areas contain no live trees or seedlings whilst other areas have a few live pines amongst dead and moribund trees. The rapid population growth rate of pine tortoise scale in Caribbean pine forests has been attributed to a combination of warm climatic conditions and a lack of natural enemies (Malumphy et al., 2012).