@article {12591,
	title = {Presence and Diversity of Streptomyces in Dendroctonus and Sympatric Bark Beetle Galleries Across North America},
	journal = {Microbial Ecology},
	volume = {61},
	number = {4},
	year = {2011},
	month = {May},
	pages = {759-768},
	abstract = {Recent studies have revealed several examples of intimate associations between insects and Actinobacteria, including the Southern Pine Beetle Dendroctonus frontalis and the Spruce Beetle Dendroctonus rufipennis. Here, we surveyed Streptomyces Actinobacteria co-occurring with 10 species of Dendroctonus bark beetles across the United States, using both phylogenetic and community ecology approaches. From these 10 species, and 19 other scolytine beetles that occur in the same trees, we obtained 154 Streptomyces-like isolates and generated 16S sequences from 134 of those. Confirmed 16S sequences of Streptomyces were binned into 36 distinct strains using a threshold of 0.2\% sequence divergence. The 16S rDNA phylogeny of all isolates does not correlate with the distribution of strains among beetle species, localities, or parts of the beetles or their galleries. However, we identified three Streptomyces strains occurring repeatedly on Dendroctonus beetles and in their galleries. Identity of these isolates was corroborated using a house-keeping gene sequence (efTu). These strains are not confined to a certain species of beetle, locality, or part of the beetle or their galleries. However, their role as residents in the woodboring insect niche is supported by the repeated association of their 16S and efTu from across the continent, and also having been reported in studies of other subcortical insects.},
	keywords = {Dendroctonus frontalis, Dendroctonus rufipennis},
	isbn = {0095-3628},
	author = {Hulcr, Jiri and Adams, Aaron S. and Raffa, Kenneth and Hofstetter, Richard W. and Klepzig, Kier D. and Currie, Cameron R.}
}
@article {8899,
	title = {Responses of Bark Beetle-Associated Bacteria to Host Monoterpenes and Their Relationship to Insect Life Histories},
	journal = {Journal of Chemical Ecology},
	volume = {37},
	number = {8},
	year = {2011},
	month = {Aug},
	pages = {808-817},
	abstract = {Bark beetles that colonize living conifers and their microbial associates encounter constitutive and induced chemical defenses of their host. Monoterpene hydrocarbons comprise a major component of these allelochemicals, and many are antibiotic to insects, fungi, and bacteria. Some bark beetle species exhaust these defenses by killing their host through mass attacks mediated by aggregation pheromones. Others lack adult aggregation pheromones and do not engage in pheromone-mediated mass attacks, but rather have the ability to complete development within live hosts. In the former species, the larvae develop in tissue largely depleted of host terpenes, whereas in the latter exposure to these compounds persists throughout development. A substantial literature exists on how monoterpenes affect bark beetles and their associated fungi, but little is known of how they affect bacteria, which in turn can influence beetle performance in various manners. We tested several bacteria from two bark beetle species for their ability to grow in the presence of a diversity of host monoterpenes. Bacteria were isolated from the mountain pine beetle, Dendroctonus ponderosae Hopkins, which typically kills trees during colonization, and the red turpentine beetle, Dendroctonus valens LeConte, which often lives in their host without causing mortality. Bacteria from D. ponderosae were gram-positive Actinobacteria and Bacilli; one yeast also was tested. Bacteria from D. valens were Actinobacteria, Bacilli, and [gamma]-Proteobacteria. Bacteria from D. valens were more tolerant of monoterpenes than were those from D. ponderosae. Bacteria from D. ponderosae did not grow in the presence of [alpha]-pinene and 3-carene, and grew in, but were inhibited by, [beta]-pinene and [beta]-phellandrene. Limonene and myrcene had little inhibitory effect on bacteria from either beetle species. Tolerance to these antibiotic compounds appears to have resulted from adaptation to living in a terpene-rich environment.},
	keywords = {Dendroctonus},
	isbn = {0098-0331},
	author = {Adams, Aaron S. and Boone, Celia K. and Bohlmann, Jorg and Raffa, Kenneth F.}
}
@article {8901,
	title = {Temporal variation in mycophagy and prevalence of fungi associated with developmental stages of Dendroctonus ponderosae (Coleoptera: Curculionidae)},
	journal = {Environmental Entomology},
	volume = {36},
	number = {1},
	year = {2007},
	month = {February},
	pages = {64-72},
	abstract = {Mycophagy by bark beetles is widespread. However, little is known regarding which developmental stages of bark beetles actually feed on fungi. To study this question, we sampled fungi associated with Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae) throughout development in naturally attacked trees. Isolations of fungi were made from phloem adjacent to brood and from brood exoskeletons and guts. Overall, the incidence of fungi with individual brood increased as brood development progressed. Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingf. and Ophiostoma montium (Rumbold) von Arx exhibited generally opposing trends in prevalence. G. clavigera was most likely to be found in phloem adjacent to prewintering third- and postwintering fourth-instar larvae. O. montium was most likely to be found in phloem adjacent to eggs, first-instar larvae, pupae, and teneral adults. In contrast to isolations made from phloem, fungi isolated from brood guts and exoskeletons were not observed to shift in prevalence. First- and third-instar larvae were often observed migrating to older portions of their galleries, indicating that they do not spend all of their time feeding at, and extending, the apex of the gallery. Our results suggest that not only are D. ponderosae brood in contact with and feeding on fungi throughout development, but also, that during development, contact of brood with a particular fungus is likely to change. Such temporal shifts in fungal symbionts may be environmentally driven and have important implications in how these fungi interact with their hosts within and across generations.},
	isbn = {0046-225X},
	author = {Adams, Aaron S. and Six, Diana L.}
}
@article {8898,
	title = {Geographic Variation in Bacterial Communities Associated With the Red Turpentine Beetle (Coleoptera: Curculionidae)},
	journal = {Environmental Entomology},
	volume = {39},
	number = {2},
	year = {2010},
	month = {April},
	pages = {406-414},
	abstract = {Bacterial communities are known to play important roles in insect life histories, yet their consistency or variation across populations is poorly understood. Bacteria associated with the bark beetle Dendroctonus valens Le Conte from eight populations, ranging from Wisconsin to Oregon, were evaluated and compared. We used the culture-independent technique of denaturing gradient gel electrophoresis to visualize bacterial diversity, or individual operational taxonomic units (Os), from individual beetles. One-way analysis of similarities was used to test for differences of bacterial communities between sites. Analysis of community profiles showed that individual beetles on average contained 10 OTUs, with frequency of association from 2 to 100\% of beetles. OTU sequences most closely matched [beta]- and [gamma]-proteobacteria, and one each matched Bacilli and Actinobacteria. Several OTUs were particularly abundant, most notably an Actinobacterium from 100\% and two Proteobacteria from 60\% of beetles sampled. Some OTUs were similar to previously described bacteria with known biochemical capabilities and ecological functions, suggesting that some bacterial associates of D. valens may contribute to its ability to exploit a resource low in nutrients and high in defensive compounds. There were significant differences of bacterial communities between sites. The strength of these differences was positively correlated with distance between sites, although additional unexplained factors also contribute to the variation.},
	keywords = {Dendroctonus valens},
	isbn = {0046-225X},
	author = {Adams, Aaron S. and Adams, Sandye M. and Currie, Cameron R. and Gillette, Nancy E. and Raffa, Kenneth F.}
}
