First report of Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae) and laurel wilt in Louisiana, USA: The disease continues westward on sassafras
Laurel wilt, caused by Raffaelea lauricola Harrington, Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), has spread rapidly through the coastal plains forests of the southeastern United States (USA) with devastating effects on redbay (Persea borbonia [L.] Spreng.; Laurales: Lauraceae) populations (Fraedrich et al. 2008; Harrington et al. 2008). The pathogen that causes the disease is a fungal symbiont of the redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera:Curculionidae: Scolytinae), and is carried in the mandibular mycangia of the beetle (Fraedrich et al. 2008). The beetle and fungus were introduced from Asia into the USA near Savannah, Georgia, around 2002 (Fraedrich et al. 2008; Harrington et al. 2011). Other members of the Lauraceae indigenous to the USA such as sassafras (Sassafras albidum [Nuttall] Nees; Laurales: Lauraceae) are also highly susceptible to the disease (Fraedrich et al. 2008), but sassafras is less common than redbay in the coastal plains of the Southeast (Koch & Smith 2008). Unlike redbay, which occurs only in the coastal plains, sassafras is widespread and occurs in forests over much of the eastern half of the USA. Many questions remain about the spread of laurel wilt on sassafras in forest types that are located inland and away from the coastal plains of the Southeast.