The pine-wood nematode, Bursaphelenchus xylophilus, in Minnesota and Wisconsin: insect associates and transmission studies.

Bursaphelenchus xylophilus was most commonly extracted from Cerambycidae emerging from nematode-infested pines. The greatest number of nematodes were extracted from Monochamus scutellatus and M. carolinensis. Low numbers of B. xylophilus were found in some buprestids. Monochamus marmorator and M. scutellatus were associated with B. xylophilus from balsam fir Abies balsamea. B. xylophilus from insects associated with balsam fir were morphologically different from insects associated with pine. Dauer larvae of B. xylophilus were concentrated in the thoracic segments of M. scutellatus and Monochamus mutator. B. xylophilus was transmitted to twigs during maturation feeding and to logs during oviposition by M. carolinensis, M. mutator and M. scutellatus. -Authors