Fungi associated with <i>Cryphalus rhusi</i> (Scolytinae; Coleoptera) infesting lacquer tree, <i>Toxicodendron vernicifluum</i>

We have examined the fungi associated with the scolytid bark beetle, <i>Cryphalus rhusi</i>, which infests the lacquer tree <i>Toxicodendron vernicifluum</i>. The fungi were also evaluated for pathogenicity in <i>T. vernicifluum</i> as a step toward clarifying the potential of the beetle for tree damage. Three fungal species, a <i>Yamadazyma</i> sp., a <i>Fusarium</i> sp., and <i>Penicillium pinophilum</i> were isolated from adult beetles that had emerged from branches. Of these, the <i>Yamadazyma</i> sp. appeared to be a close associate of the beetle, since it was isolated from all individuals used in the study, while the others were much less frequent. Pathogenicity tests revealed that the <i>Fusarium</i> sp. caused slightly larger lesions (by 2 mm) than the negative controls, whereas the <i>Yamadazyma</i> sp. did not cause any symptoms. We conclude that <i>C. rhusi</i>, with its associated fungi, is not likely to be a serious pest for <i>T. vernicifluum</i>.