Symbiosis, 37 (2004) 207-232 207 Balaban, Philadelphia/Rehovot Review article. Dendroctonus Bark Beetles as Model Systems for Studies on Symbiosis DIANA L. srx" and KIER D. KLEPZIG2 l Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, Missoula, MT 59812, USA, Tel. +1-406-243-5573, Fax. +1-406-243-6656, Email.
[email protected]; 2 USDA Forest Service, Southern Research Station, Pineville, LA 71360, USA Received September 11, 2003; Accepted January 21, 2004 Abstract Several characteristics of Dendroctonus-fungus symbioses make these associations ideal model systems for studying the development and maintenance of ectosymbioses. Within this relatively small genus, structures specialized for dissemination of symbionts (mycangia) have evolved at least three times, allowing comparisons of symbioses within and among mycangial and non-mycangial lineages. In addition to possessing highly specific symbionts that exhibit parallel cladogenesis with their hosts, many beetles are also associated with what appear to be "invaders". Dendroctonus species also exhibit considerable variation in life history and host tree range, factors which are likely to greatly affect the degree and manner in which they interact with fungi. In this paper, we develop a framework for developing and testing predictions on Dendroctonus-fungus symbioses. To develop the framework we categorized the nineteen species of Dendroctonus into five groups based on phylogenetic lineage. For each species, we summarized their life histories and associations with fungi. Using this framework, we then develop predictions on where particular association types are most likely to occur. Finally, we present three examples of Dendroctonus-fungus symbioses. Keywords: Ophiostoma, Leptographium, Entomocoriicium, mycangium, mycangia, mycangial fungi, mutualism, antagonism Presented at the 4th International Symbiosis Congress, August 17-23, 2003, Halifax, Canada "The author to whom correspondence should be sent.