Leptographium longiclavatum: a new species associated with Dendroctonus ponderosae
In British Columbia (Canada), an epidemic of Dendroctonus ponderosae (EPPO A1 list) has been observed for the last 12 years. It is reported that the pest has spread over 10.1 million ha and infested 173.5 million m3 of Pinus contorta var. latifolia (lodgepole pine). Damage is caused by the insect itself which feeds on the phloem and by associated fungi which discolour sapwood and disrupt transportation of water to the tree crown. The infested trees are killed by simultaneous infection of the beetle and fungi. During studies on fungal species associated with the beetle, a new species of Leptographium was isolated from D. ponderosae, from bark and stained sapwood of infested P. contorta var. latifolia. So far, only Ophiostoma montium and O. clavigerum were reported in association with D. ponderosae. The new Leptographium species could be clearly distinguished from the Leptographium anamorph of O. clavigerum. The new species was described and called Leptographium longiclavatum. Leptographium species are usually weak pathogens (although there are a few exceptions like L. wageneri), however more studies are needed on the pathogenicity of L. longiclavatum to pine trees.
Lee S, Kim JJ, Breuil C (2005) Leptographium longiclavatum sp. nov., a new species associated with the mountain pine beetle, Dendroctonus ponderosae.
Mycological Research, 109(10), 1162-1170.