Ayres Abstracts

Klepzig, K.D., J.C. Moser, M.J. Lombardero, M.P. Ayres, R.W. Hofstetter, and C.J. Walkinshaw. 2001. Mutualism and antagonism: Ecological interactions among bark beetles, mites, and fungi. Pages 237-269 in M.J. Jeger and N.J. Spence, editors. Biotic interactions in plant-pathogen associations. CABI publishing, New York. Full text in pdf.
Relationships among symbiotic organisms may change over time and ranges of resources. Other organisms may indirectly facilitate or interfere with these relationships. Interactions among bark beetles and their associated fungi and mites are complex examples of the manner in which symbioses change and are indirectly affected by other organisms. These complex relationships have been extensively studied in the southern pine beetle (SPB), a bark beetle that kills healthy living trees through mass colonization. The SPB is consistently associated with three main fungi. Two of these fungi (Ceratocystiopsis ranaculosus and Entomocorticium sp. A) are carried in a specialized structure (mycangium) in female SPB. The third fungus is carried phoretically on the exoskeleton. Both O. minus and C. ranaculosus are also carried by phoretic mites of SPB. Due to the effects of these fungi on SPB larval development, their competitive interactions have significant implications. The two mycangial fungi provide nutrition to developing larvae, while the phoretic fungus interferes with larval development. These interactions appear to be mediated by phoretic mites which have developed mutualistically symbiotic relationships iwth the SPB-associated fungi they vector. The multiple interdependencies in this system provide novel opportunities for control, and further research on, this damaging forest pest complex.

 

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