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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #255102
Title: Leptographium tereforme sp. nov. and other Ophiostomatales isolated from the root-feeding bark beetle, Hylurgus ligniperda, in California

Author
item KIM, SUIJIN - Iowa State University
item HARRINGTON, THOMAS - Iowa State University
item Lee, Jana
item SEYBOLD, STEVEN - Forest Service (FS)

Submitted to: Mycologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2010
Publication Date: 6/17/2010
Citation: Kim, S., Harrington, T.C., Lee, J.C., Seybold, S.J. 2010. Leptographium tereforme sp. nov. and other Ophiostomatales isolated from the root-feeding bark beetle, Hylurgus ligniperda, in California. Mycologia. 103:152-163.

Interpretive Summary: The redhaired pine bark beetle, Hylurgus ligniperda F., is originally from Europe but was found in Southern California in 2003. This bark beetle feeds in the phloem layer or pine roots and stumps. Due to its feeding habits, the bark beetle can readily vector fungal pathogens from tree to tree, including the causative agent of blue-stain. In this study, fungal pathogens (in the Ophiostomatales group) were isolated from 118 adult redhaired pine bark beetles collected live from infested logs of Aleppo and Italian stone pine at two sites in California. In total, eight species of fungal species were identified, and seven species that were occasionally isolated were unidentified. The most frequently isolated species were Ophiostoma ips and Grosmannia galeiforme, which were isolated from 31% and 23% of the 118 beetles, respectively. The other species isolated included O. piceae (isolated from 9% of the beetles), O. querci (8%), and Leptographium tereforme sp. nov. (6%). Grosmannia huntii, L. serpens, three Sporothrix species, O. floccosum, O. stenoceras, two unidentified Hyalorhinocladiella sp., and a sterile fungus, were each isolated from less then 5% of the beetles. Most of the identified species were already known in the United States and have been found in association with redhaired pine bark beetle in other countries. However, the new species, L. tereforme, and G. galeiforme were recorded from the United States for the first time, and this is the first report of L. serpens from western North America.

Technical Abstract: The redhaired pine bark beetle, Hylurgus ligniperda F., is native to Europe but was discovered in Los Angeles, California in 2003. This root- and stump-feeding bark beetle is a common vector of Ophiostomatales, which are potential tree pathogens or causes of blue-stain of conifer sapwood. In this study, Ophiostomatales were isolated on a cycloheximide-amended medium from 118 adult H. ligniperda collected from infested logs of Pinus halepensis and P. pinea at two sites in California. In total, eight species of Ophiostomatales were identified, and seven species that were occasionally isolated were unidentified. The most frequently isolated species were Ophiostoma ips and Grosmannia galeiforme, which were isolated from 31% and 23% of the 118 beetles, respectively. The other species isolated included O. piceae (isolated from 9% of the beetles), O. querci (8%), and Leptographium tereforme sp. nov. (6%). Grosmannia huntii, L. serpens, three Sporothrix species, O. floccosum, O. stenoceras, two unidentified Hyalorhinocladiella sp., and a sterile fungus, were each isolated from less then 5% of the beetles. Most of the identified species were already known in the United States and have been found in association with H. ligniperda in other countries. However, the new species, L. tereforme, and G. galeiforme were recorded from the United States for the first time, and this is the first report of L. serpens from western North America.