Xyleborus glabratus attacks and systemic colonization by Raffaelea lauricola associated with dieback of Cinnamomum camphora in the southeastern United States

摘要: Summary Laurel wilt, caused by Raffaelea lauricola, is responsible for extensive mortality of redbay and other American members the Lauraceae in southeastern United States. lauricola a mycangial symbiont ambrosia beetle (Xyleborus glabratus), fungus were accidentally introduced from Asia. Branch dieback camphortree (Cinnamomum camphora), an Asian member Lauraceae, has been occasionally observed areas where laurel wilt decimated populations, R. was isolated such camphortrees. However, role X. glabratus this branch remains unclear. Examination camphortrees on Jekyll Island, Georgia showed that healthy-appearing trees those with had attacked glabratus, but four times as many attacks. routinely discoloured xylem near tunnels healthy dieback. Single-point inoculations stems mature, failed to induce wilt-like symptoms or dieback, although discoloration scattered throughout xylem, reisolated irregularly at various heights some inoculated trees. In growth chamber experiments, single-point resulted systemic colonization no saplings. contrast, multiple points along stem (simulating attacks vector) symptoms, including brownish, diffuse xylem. Camphortree appears be more resistant than species vascular lauricola. The does colonize systemically, however, can apparently cause This suggests may provide brood material Asia it