OPHIOSTOMA-CLAVIGERUM IS THE MYCANGIAL FUNGUS OF THE JEFFREY PINE-BEETLE, DENDROCTONUS-JEFFREYI

Dendroctonus jeffreyi and D. ponderosae are sibling species of bark be etles (Coleoptera: Scolytidae) with few morphological and molecular ge netic differences. The two species are believed to have diverged relat ively recently. Dendroctonus jeffreyi colonizes only Pinus jeffreyi, w hile D. ponderosae colonizes up to thirteen Pinus spp., but not P. jef freyi. Adult beetles of both D. jeffreyi and D. ponderosae carry symbi otic fungi in mycangia located on the maxillary cardines. Dendroctonus ponderosae was known to carry two fungi, Ophiostoma clavigerum and O. montium, in its mycangia. However, it was not known which fungi might be carried by D. jeffreyi. Fungi were isolated from the mycangia of o ver 900 D. jeffreyi collected from a large portion of its geographic r ange. Using morphology, isozyme phenotypes, and growth rates at differ ent temperatures, all isolates from D. jeffreyi mycangia were determin ed to be O. clavigerum; O. montium was never isolated from D. jeffreyi mycangia.