Discovery of a phoretic association between Bursaphelenchus doui (Nematoda: Aphelenchoididae) and Monochamus saltuarius and Acalolepta sejuncta (Coleoptera: Cerambycidae)

Summary To investigate the phoretic association between nematodes in the genus Bursaphelenchus and cerambycid beetles in north-eastern Japan, Pinus densiflora logs were placed in two pine forests in the towns of Yamada and Hiranai as beetle oviposition sites. At 1-2 years after oviposition, adults of Monochamus saltuarius emerged from the logs placed in Yamada and adults of Acalolepta sejuncta and A. fraudatrix emerged from the logs placed in Hiranai, and Bursaphelenchus nematodes were recovered from two of these species (M. saltuarius and A. sejuncta). Morphometrics and a phylogenetic analysis of the internal transcribed spacer regions 1 and 2 and the 5.8S ribosomal RNA gene indicated that both of these nematode populations were B. doui, which has previously only been known to use M. subfasciatus and A. fraudatrix as vectors. Therefore, this study demonstrated that this nematode utilises at least four species of beetles belonging to two genera as vectors in the field.