@article {13276,
	title = {Bursaphelenchus rufipennis n. sp. (Nematoda: Parasitaphelenchinae) and redescription of Ektaphelenchus obtusus (Nematoda: Ektaphelenchinae), associates from nematangia on the hind wings of Dendroctonus rufipennis (Coleoptera: Scolytidae)},
	journal = {Nematology},
	volume = {10},
	number = {6},
	year = {2008},
	month = {2008},
	pages = {925-955},
	type = {Article},
	abstract = {Two species of aphelench, Bursaphelenchus rufipennis n. sp. and Ektaphelenchus obtusus, were isolated from the {\textquoteright}nematangia{\textquoteright}, cocoon-like structures found at the base of the hind wings of Dendroctonus rufipennis. The nematangia contained adult females of E. obtusus and the dauer juveniles of B. rufipennis n. sp. Only B. rufipennis n. sp. could be cultured on Monilinia fructicola on LGPDA (lactic acid-treated, glycerol-supplemented, potato dextrose agar). The new species of Bursaphelenchus is described and figured and some additional morphological characters are ascribed to E. obtusus, E. josephi, E. sandiaensis, E. smaelus (= E. prolobos) and E. terebranus after examination of type and/or voucher specimens. Bursaphelenchus rufipennis n. sp. has an adult body length of ca 500-1000 [mu]m, medium a ratios (ca 25-38 for females and ca 30-40 for males), b ratios of ca 8-13 (female) and 7-11 (male), c ratios of ca 15-22 (female and male), c{\textquoteright} ratios of ca 3-4 (female) and ca 2-3 (male), and is characterised by three incisures in the lateral field, mitten-shaped spicules and a conical female tail that curves ventrally and possesses a variable tail tip. The new species is morphologically closest to B. corneolus, B. curvicaudatus, B. gerberae, B. paracorneolus and B. talonus. Morphological examination of type and/or voucher specimens of five Ektaphelenchus species revealed coarse transverse body annulation and three pairs of male caudal papillae (except for the two species where males are not described). Clear typological differences were observed among these five Ektaphelenchus species in the structure of the lip region, presence/absence of stylet knobs and male spicule morphology. Although these characters have not been consistently documented in the past, they may be diagnostic for species in the genus. Molecular phylogenetic analysis based on SSU and D2/D3 LSU sequences revealed that B. rufipennis n. sp. was closest to B. paracorneolus and that E. obtusus was closest to species of Ektaphelenchoides and a Cryptaphelenchus sp.},
	keywords = {Dendroctonus rufipennis},
	isbn = {1388-5545},
	author = {Kanzaki, Natsumi and Giblin-Davis, Robin M. and Cardoza, Yasmin and Ye, Weimin and Raffa, Kenneth F. and Center, Barbara J.}
}
@article {13203,
	title = {Fuel Complex Alterations Associated with Spruce Beetle-Induced Tree Mortality in Intermountain Spruce/Fir Forests},
	journal = {Forest Science},
	volume = {57},
	number = {3},
	year = {2011},
	month = {Jun},
	pages = {232-240},
	abstract = {Tree mortality caused during extensive outbreaks of spruce beetle (Dendroctonus rufipennis Kirby (Coleoptera: Curculionidae)) has been assumed to increase hazardous fuel loads and consequently influence fire behavior, occurrence, and effects. However, little research has been done to quantify or qualify how spruce beetle-induced tree mortality may alter fuel complexes during the course of an outbreak. The objective of our research was to determine how fuel complexes differ between stands with endemic populations of spruce beetle, stands experiencing current outbreaks, and stands with postoutbreak spruce beetle-induced tree mortality. We measured ground, surface, and aerial fuels in spruce fir stands assigned into one of three spruce beetle condition classes: endemic, epidemic, or postepidemic. These stands were located on the Manti-LaSal and Fish lake National Forests in southcentral and southern Utah. We used analysis of variance (ANOVA) to compare mean differences in stand attributes and fuel variables between the three spruce beetle condition classes. The mean amount of down woody surface fuel (tonnes/ha) in the 100-hour size class in epidemic stands was significantly greater than that in endemic stands. Mean litter depth and amount was significantly greater in epidemic stands than in endemic and postepidemic stands. A significant increase for most estimates of live and dead herbaceous material was detected in epidemic stands and postepidemic stands compared with that in stands not affected by the spruce beetle. Likewise, significant increases in live shrub material were detected in postepidemic stands. Spruce fir stands also had significantly less live aerial fuels after outbreaks than endemic stands. FOR. SCI. 57(3):232-240.},
	keywords = {Dendroctonus rufipennis},
	isbn = {0015-749X},
	author = {Jorgensen, Carl Arik and Jenkins, Michael James}
}
@article {13091,
	title = {Bark beetles, fuels, fires and implications for forest management in the Intermountain West},
	journal = {Forest Ecology and Management},
	volume = {254},
	number = {1},
	year = {2008},
	month = {January 15},
	pages = {16-34},
	type = {Article},
	abstract = {Bark beetle-caused tree mortality in conifer forests affects the quantity and quality of forest fuels and has long been assumed to increase fire hazard and potential fire behavior. In reality, bark beetles, and their effects on fuel accumulation, and subsequent fire hazard, are poorly understood. We extensively sampled fuels in three bark beetle-affected Intermountain conifer forests and compared these data to existing research on bark beetle/fuels/fire interactions within the context of the disturbance regime. Data were collected in endemic, epidemic and post-epidemic stands of Douglas-fir, lodgepole pine and Engelmann spruce. From these data, we evaluated the influence of bark beetle-caused tree mortality on various fuels characteristics over the course of a bark beetle rotation. The data showed that changes in fuels over time create periods where the potential for high intensity and/or severe fires increases or decreases. The net result of bark beetle epidemics was a substantial change in species composition and a highly altered fuels complex. Early in epidemics there is a net increase in the amount of fine surface fuels when compared to endemic stands. In post-epidemic stands large, dead, woody fuels, and live surface fuels dominate. We then discuss potential fire behavior in bark beetle-affected conifer fuels based on actual and simulated fuels data. Results indicated that for surface fires both rates of fire spread and fireline intensities were higher in the current epidemic stands than in the endemic stands. Rates of spread and fireline intensities were higher in epidemic stands due, however, to decreased vegetative sheltering and its effect on mid-flame wind speed, rather than changes in fuels. Passive crown fires were more likely in post-epidemic stands, but active crown fires were less likely due to decreased aerial fuel continuity. We also discuss the ecological effects of extreme fire behavior. Information is presented on managing forests to reduce the impact of bark beetle outbreaks and the interplay between management, bark beetle populations, fuels and fire hazard and behavior. (C) 2007 Elsevier B.V. All rights reserved.},
	keywords = {Dendroctonus ponderosae, Dendroctonus pseudotosugae, Dendroctonus rufipennis},
	isbn = {0378-1127},
	author = {Jenkins, Michael J. and Hebertson, Elizabeth and Page, Wesley and Jorgensen, C. Arik}
}
@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 {11997,
	title = {The influence of fallen tree timing on spruce beetle brood production},
	journal = {Western North American Naturalist},
	volume = {67},
	number = {3},
	year = {2007},
	month = {July},
	pages = {452-460},
	abstract = {This study compared brood production of the spruce beetle (Dendroctonus rufipennis Kirby (Coleoptera: Curculionidae. Scolytinae)) in downed host material felled during summer and spring seasons on the Wasatch Plateau in south central Utah. Thirty-three matched pairs of Engelmann spruce (Picea engelmannii Parry ex Engelm.) trees were selected for study in spring 1996. One tree of each pair was cut during August 1996 (summer-felled) and the other tree was cut in early April 1997 (spring-felled), so that trees would be colonized by spruce beetles of the same flight period. Brood adults were collected and counted from bark samples, which were removed from the top, bottom. and sides of all sample trees in October 1998. The number of emergent adults produced in June 1999 was determined from exit holes counted in bark samples removed form these same locations. Mixed-model procedures were used to compare differences in the mean number of adults produced in summer-felled verus spring-felled trees in each year. The results indicated that significantly fewer spruce beetles were produced in summer-felled trees than in spring-felled trees. More brood adults were also present in, or emerged form, unexposed hole aspects (bottom, north, and east) of sample trees than exposed aspects (top, south and west). These finding suggest that disturbances providing spruce beetles with an abundance of fresh host material in the spring result in the greatest potential for spruce beetle production, particularly beneath unexposed bark aspects. Examples of such disturbances include snow avalanches, blowdown, and snow and ice damage.},
	keywords = {Dendroctonus rufipennis},
	isbn = {1527-0904},
	author = {Hebertson, Elizabeth G. and Jenkins, Michael J.}
}
@article {11998,
	title = {Climate factors associated with historic spruce beetle (Coleoptera: Curculionidae) outbreaks in Utah and Colorado},
	journal = {Environmental Entomology},
	volume = {37},
	number = {2},
	year = {2008},
	month = {April},
	pages = {281-292},
	type = {Article},
	abstract = {This study investigated relationships between climate and historic spruce beetle, Dendroctonits rufipennis Kirby (Coleoptera: Curculionidae), outbreaks in northern and southeastern Utah and western Colorado between 1905 and 1996. A chronology of outbreak years was constructed from historic records, research papers, newspapers, and other sources of information. Historic climate data for the region included annual and mean monthly temperature and precipitation, in addition to Palmer drought severity index (PDSI) values estimated from tree rings. Classification and regression tree analysis (CART) was used to identify those climate factors most important for predicting historic spruce beetle outbreaks. The factors identified by the best CART model included mean December temperature, mean September temperature 1 yr before outbreak years, the mean estimated PDSI value of the 5-yr period before outbreak years, and mean October precipitation. The resulting model correctly classified nonoutbreak and outbreak years 67 and 70\% of the time, respectively.},
	keywords = {Dendroctonus rufipennis},
	isbn = {0046-225X},
	author = {Hebertson, Elizabeth G. and Jenkins, Michael J.}
}
@article {11879,
	title = {Prepupal diapause and instar IV developmental rates of the spruce beetle, Dendroctonus rufipennis (Coleoptera: Curculionidae, Scolytinae)},
	journal = {Journal of Insect Physiology},
	volume = {57},
	number = {10},
	year = {2011},
	month = {Oct},
	pages = {1347-1357},
	abstract = {The spruce beetle, Dendroctonus rufipennis (Kirby), is an important mortality agent of native spruces throughout North America. The life-cycle duration of this species varies from 1 to 3 years depending temperature. The univoltine cycle (one generation per year) is thought to maximize outbreak risk and accelerate host mortality in established outbreaks. Prepupal diapause is associated with the semivoltine cycle (one generation per 2 years) and we investigated thermal conditions that result in diapause induction. Preliminary experiments used respirometry in an attempt to distinguish the diapause state of experimental insects but the technique was apparently confounded by low respiration before and during pupation, regardless of diapause status. Therefore, diapause induction was deduced using developmental delays. The observed developmental response was not a "switch", with developmental delay either present or absent, but instead varied continuously. We found that temperatures <15 [degree]C from instar Ill through mid-instar IV were associated with developmental delays beyond that expected from cool temperatures. Moreover, the duration of exposure to cool temperatures was important in determining the degree of developmental delay. Small, if any, delays were observed if the cumulative exposure to <15 [degree]C was <20 d whereas >40 d cumulative exposure was associated with distinct developmental suppression. Intermediate exposure to cool temperatures resulted in minor developmental delays. We used our results to parameterize a maximum likelihood estimation model of temperature-dependent instar IV developmental rates, including the effect of diapause. This model can be included as part of a spruce beetle phenology model for predicting population dynamics. Published by Elsevier Ltd.},
	keywords = {Dendroctonus rufipennis},
	isbn = {0022-1910},
	author = {Hansen, E. Matthew and Bentz, Barbara J. and Powell, James A. and Gray, David R. and Vandygriff, James C.}
}
@article {11286,
	title = {Semiochemical sabotage: behavioral chemicals for protection of western conifers from bark beetles},
	journal = {U S Forest Service General Technical Report PNW},
	volume = {784},
	year = {2009},
	month = {April},
	pages = {85-109},
	abstract = {The discovery and elucidation of volatile behavioral chemicals used by bark beetles to locate hosts and mates has revealed a rich potential for humans to sabotage beetle host-finding and reproduction. Here, we present a description of currently available semiochemical methods for use in monitoring and controlling bark beetle pests in western conifer forests. Delivery systems include hand-applied methods, such as semiochemical-releasing bubblecaps, pouches, and "puffers," as well as products that can be applied by aircraft such as semiochemical-releasing flakes. Descriptions of both attractant-based ("pull") and anti-attractant-based ("push") strategies are provided. Examples are provided for the major bark beetle pests in western North America, including the mountain pine beetle (Dendroctonus ponderosae Hopkins), western pine beetle (Dendroctonus brevicomis LeConte), the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins), the spruce beetle (Dendroctonus rufipennis (Kirby)), and the red turpentine beetle (Dendroctonus valens LeConte),.},
	keywords = {Dendroctonus brevicomis, Dendroctonus ponderosae, Dendroctonus pseudotsugae, Dendroctonus rufipennis, Dendroctonus valens},
	isbn = {0363-6224},
	author = {Gillette, Nancy E. and Munson, A. Steve}
}
@article {10674,
	title = {Disturbance, structure, and composition: spruce beetle and Engelmann spruce forests on the Markagunt Plateau, Utah},
	journal = {Forest Ecology and Management},
	volume = {244},
	number = {1-3},
	year = {2007},
	month = {June 15},
	pages = {16-23},
	abstract = {In the 1990s a spruce beetle (Dendroctonus rufipennis) outbreak killed nearly all canopy Engelmann spruce (Picea engelmannii) across the Markagunt Plateau, southern Utah, USA. We quantified attributes of the forest before and after the spruce beetle outbreak, including tree ages, structure and composition on three sites. Greater than 99\% of the Engelmann spruce measured in this study were dead and 93\% of those died as a result of the beetle outbreak. Age structure analysis revealed each site had originally regenerated from a different antecedent disturbance, and not from a single, landscape-wide event comparable to the recent spruce beetle outbreak. Profound structural and compositional changes from spruce dominance to subalpine fir (Abies lasiocarpa), aspen (Populus tremuloides), or limber pine (Pinus flexilis) were found. No site was resistant to the spruce beetle and post-outbreak forest composition suggested that the response to the disturbance is at least partially due to species diversity. We suggest short-term (decades) system response will tend toward structures similar to pre-outbreak conditions however, composition will differ. Sparse Engelmann spruce regeneration (6\% of understory trees <5 cm diameter at breast height) compared with subalpine fir (62\%) and aspen (32\%) will likely preclude spruce from dominance for many decades. Long-term (centuries) forest reorganization will tend toward structures similar to the pre-outbreak system (i.e. forest); however, dominance by Engelmann spruce will likely take longer.},
	keywords = {Dendroctonus rufipennis},
	isbn = {0378-1127},
	author = {DeRose, R. Justin and Long, James N.}
}
@article {9852,
	title = {Multipartite symbioses among fungi, mites, nematodes, and the spruce beetle, Dendroctonus rufipennis},
	journal = {Environmental Entomology},
	volume = {37},
	number = {4},
	year = {2008},
	month = {August},
	pages = {956-963},
	type = {Article},
	abstract = {The spruce beetle, Dendroctonus rufipennis, is an eruptive forest pest of significant economic and ecological importance. D. rufipennis has symbiotic associations with a number of microorganisms, especially the ophiostomatoid fungus Leptographium abietinum. The nature of this interaction is only partially understood. Additionally, mite and nematode associates can mediate bark beetle-fungal interactions, but this has not yet been studied for spruce beetles. In this study, we found eight mite species associated with spruce beetles: Tarsonemus ips, T. endophloeus, Histiogaster arborsignis, Dendrolaelaps quadrisetus, Proctolaelaps hytricoides, Trichouropoda alascae, T. n. sp. nr dalarenaensis, and Urobovella n. sp 767. The most prevalent species was H. arborsignis. In addition, 75\% of beetles examined carried nematodes, with six species represented. These included a new species of Parasitorhabditis, Ektaphelenchus obtusus, Bursaphelenchus n. sp. 727, Aphelenchoides n. sp., Panagrolaimus sp., and Mykoletzkya ruminis. H. arborsignis showed strong feeding and oviposition preferences for L. abietinum among four fungal species tested in laboratory assays. Information on our attempts to culture the various nematode species collected from D. rufipennis is also provided. Bursaphelenchus were cultured from D. rufipennis nematangia plated on agar containing L. abietinum but not sterile agar, Thus, L. abietinum plays an important role in these gallery communities, affecting the tree-killing bark beetle, its phoretic mites, and nematodes. These data add to our understanding of bark beetle-microorganism interactions.},
	keywords = {Dendroctonus rufipennis},
	isbn = {0046-225X},
	author = {Cardoza, Yasmin J. and Moser, John C. and Klepzig, Kier D. and Raffa, Kenneth F.}
}
@article {9853,
	title = {Survey and phylogenetic analysis of culturable microbes in the oral secretions of three bark beetle species},
	journal = {Entomologia Experimentalis Et Applicata},
	volume = {131},
	number = {2},
	year = {2009},
	month = {May},
	pages = {138-147},
	abstract = {In a recent study, we reported a previously undescribed behavior in which a bark beetle exuded oral secretions containing bacteria that have antifungal properties, and hence defend their galleries against pervasive antagonistic Hyphomycete fungi. Actinobacteria, a group known for their antibiotic properties, were the most effective against fungi that invade the spruce beetle galleries. In the present study, we describe the isolation and identification of microorganisms from oral secretions of three bark beetles (Coleoptera: Curculionidae: Scolytinae): the spruce beetle, Dendroctonus rufipennis Kirby, the mountain pine beetle, Dendroctonus ponderosae Hopkins, and the pine engraver, Ips pini Say. Bacteria isolated from these three species span the major bacterial classes [alpha]-, [beta]-, and [gamma]-Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, except for D. ponderosae, which yielded no [alpha]-proteobacteria or Bacteroidetes isolates. Spruce beetles and pine engraver beetles had similar numbers of [alpha]-proteobacteria isolates, but pine engravers yielded twice as many Bacteroidetes isolates as spruce beetles. In contrast, mountain pine beetles yielded more isolates in the [beta]- and [gamma]-proteobacteria than spruce beetles and pine engravers. The highest percentage of Actinobacteria was obtained from spruce beetles, followed by pine engravers and mountain pine beetles. All of the fungal isolates obtained from the three beetle species were Ascomycetes. The greatest fungal diversity was obtained in spruce beetles, which had nine species, followed by pine engravers with five, and mountain pine beetles with one.},
	keywords = {Dendroctonus ponderosae, Dendroctonus rufipennis, Ips pini},
	isbn = {0013-8703},
	author = {Cardoza, Yasmin J. and Vasanthakumar, Archana and Suazo, Alonso and Raffa, Kenneth F.}
}
@article {9361,
	title = {Climate Change and Bark Beetles of the Western United States and Canada: Direct and Indirect Effects},
	journal = {Bioscience},
	volume = {60},
	number = {8},
	year = {2010},
	month = {Sep 10},
	pages = {602-613},
	abstract = {Climatic changes are predicted to significantly affect the frequency and severity of disturbances that shape forest ecosystems. We provide a synthesis of climate change effects on native bark beetles, important mortality agents of conifers in western North America. Because of differences in temperature-dependent life-history strategies, including cold-induced mortality and developmental timing, responses to warming will differ among and within bark beetle species. The success of bark beetle populations will also be influenced indirectly by the effects of climate on community associates and host-tree vigor, although little information is available to quantify these relationships. We used available population models and climate forecasts to explore the responses of two eruptive bark beetle species. Based on projected warming, increases in thermal regimes conducive to population success are predicted for Dendroctonus rufipennis (Kirby) and Dendroctonus ponderosae Hopkins, although there is considerable spatial and temporal variability. These predictions from population models suggest a movement of temperature suitability to higher latitudes and elevations and identify regions with a high potential for bark beetle outbreaks and associated tree mortality in the coming century.},
	keywords = {Dendroctonus rufipennis},
	isbn = {0006-3568},
	author = {Bentz, Barbara J. and Regniere, Jacques and Fettig, Christopher J. and Hansen, E. Matthew and Hayes, Jane L. and Hicke, Jeffrey A. and Kelsey, Rick G. and Negron, Jose F. and Seybold, Steven J.}
}
@article {8540,
	title = {Nesting ecology of boreal forest birds following a massive outbreak of spruce beetles},
	journal = {Journal of Wildlife Management},
	volume = {71},
	number = {1},
	year = {2007},
	month = {February},
	pages = {51-63},
	abstract = {We studied breeding dark-eyed juncos (Junco hyemalis), yellow-rumped warblers (Dendroica coronata), and spruce-nesting birds from 1997 to 1998 among forests with different levels of spruce (Picea spp.) mortality following an outbreak of spruce beetles (Dendroctonus rufipennis) in Alaska, USA. We identified species using live and beetle-killed spruce for nest sites and monitored nests to determine how the outbreak influenced avian habitat selection and reproduction. We tested predictions that 1) nesting success of ground-nesting juncos would increase with spruce mortality due to proliferation of understory vegetation available to conceal nests from predators, 2) nesting success of canopy-nesting warblers would decrease with spruce mortality due to fewer live spruce in which to conceal nests, and 3) both species would alter nest-site selection in response to disturbance. Juncos did not benefit from changes in understory vegetation; nesting success in highly disturbed stands (46\%) was comparable to that in undisturbed habitats throughout their range. In stands with low spruce mortality, nesting success of juncos was low (5\%) and corresponded with high densities of red squirrels (Tamiasciurus hudsonicus). Yellow-rumped warblers nested exclusively in spruce, but success did not vary with spruce mortality. As disturbance increased, nesting warblers switched from selecting forest patches with high densities of live white spruce (Picea glauca) to patches with beetle-killed spruce. Warblers also placed nests in large-diameter live or beetle-killed spruce, depending on which was more abundant in the stand, with no differences in nesting success. Five of the 12 other species of spruce-nesting birds also used beetle-killed spruce as nest sites. Because beetle-killed spruce can remain standing for >50 years, even highly disturbed stands provide an important breeding resource for boreal forest birds. We recommend that boreal forest managers preserve uncut blocks of infested forest within managed forest landscapes and practice partial harvest of beetle-killed spruce rather than commercial clear-cutting of infested stands in order to sustain breeding bird populations until natural reforestation occurs. Because breeding densities do not always reflect fitness, assessing impacts of a massive natural disturbance should include measuring impacts of changes in vegetation on both reproductive success and predator-prey dynamics.},
	keywords = {Dendroctonus rufipennis},
	isbn = {0022-541X},
	author = {Matsuoka, Steven M. and Handel, Colleen M.}
}
