Interactions of the Pathogen, its Insect Vector, and Fungi in Pine Wilt Disease

Abstract

The pinewood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease, and is vectored from wilt-killed to healthy pine trees by adults of the Japanese pine sawyer, Monochamus alternatus. This relationship between B. xylophilus and M. alternatus is greatly affected by fungi. Wood-inhabiting fungi affect the reproduction of B. xylophilus in wilt-killed trees, and then the number of B. xylophilus carried by a Monochamus beetle from wilt-killed to healthy trees. Entomopathogenic fungi prevent M. alternatus from transmitting B. xylophilus to healthy trees. Therefore, these fungi can determine the dynamics of the disease. If these fungi are effectively used and applied, we could control the disease successfully. Microbial controls of B. xylophilus and M. alternatus by fungi are being developed.