@article {15145,
	title = {The role of vision in the host orientation behaviour of Hylobius warreni},
	journal = {Agricultural and Forest Entomology},
	volume = {14},
	number = {3},
	year = {2012},
	month = {August},
	pages = {286-294},
	abstract = {1 Visual stimuli, often in combination with olfactory stimuli, are frequently important components of host selection by forest-dwelling phytophagous insects. 2 Warren root collar weevil Hylobius warreni Wood (Coleoptera: Curculionidae) is a native insect in western Canada, where larvae feed primarily on lodgepole pine Pinus contorta and can girdle and kill young trees. This weevil is an emerging problem in areas heavily impacted by mountain pine beetle Dendroctonus ponderosae Hopkins. 3 No olfactory attractants have been identified for this insect, making monitoring and management difficult. Thus, we investigated the role of vision in the host-finding behaviour of Warren root collar weevil in the absence of known olfactory cues. 4 We conducted three experiments in field enclosure plots aiming to characterize aspects of host-finding behaviour by adult Warren root collar weevil. 5 We found that both male and female weevils were readily attracted to vertical plastic silhouettes in the shape of a trunk, crown or tree at distances of less than 4 m. This pattern of attraction persisted over 2 years in two slightly different study designs. Blinding the insects removed their ability to orient to these silhouettes, indicating that host-finding behaviour has a strong visual component. The use of different colour trunks and crowns (black, white and green) did not change the patterns of attraction of the insects to the silhouettes. 6 Exploiting visual attraction in this walking insect may present a new management tool in forest protection strategies.},
	keywords = {Dendroctonus ponderosae},
	isbn = {1461-9555},
	author = {Machial, Laura A. and B.S. Lindgren and Aukema, Brian H.}
}
@article {15146,
	title = {Dispersal of Warren Root Collar Weevils (Coleoptera: Curculionidae) in Three Types of Habitat},
	journal = {Environmental Entomology},
	volume = {41},
	number = {3},
	year = {2012},
	month = {Jun},
	pages = {578-586},
	abstract = {Warren root collar weevil, Hylobius warreni Wood, is a native, flightless insect distributed throughout the boreal forest of North America. It is an emerging problem in young plantings of lodgepole pine, Pinus contorta variety latifolia, in western Canada, where larval feeding can kill young trees by girdling the root collar. Susceptible plantings are becoming more abundant following salvage harvesting and replanting activities in the wake of an ongoing epidemic of mountain pine beetle, Dendroctonus ponderosae (Hopkins). Previous studies using mark-trap-recapture methods found that movement rates of adult H. warreni were elevated in areas with high numbers of dead trees, consistent with a hypothesis that the insects immigrate from stands with high mountain pine beetle-caused tree mortality to young plantings in search of live hosts. Sampling methods were necessarily biased to insects captured in traps; however, potentially missing individuals that had died, left the study area, or simply remained stationary. Here, we used harmonic radar to examine weevil movement in three different habitats: open field, forest edge, and within a forest. We were able to reliably monitor all but two of 36 insects initially released, over 96 h (4 d). Weevils released in the open field had the highest rates of movement, followed by weevils released at the forest edge, then weevils released within the forest. Movement declined with decreasing ambient air temperature. Our results suggest that weevils tend to be relatively stationary in areas of live hosts, and hence may concentrate in a suitable area once such habitat is found.},
	keywords = {Hylobius warreni},
	isbn = {0046-225X},
	author = {Machial, Laura A. and B.S. Lindgren and Steenweg, Robin W. and Aukema, Brian H.}
}
@article {14329,
	title = {The role of vision in the host orientation behaviour of Hylobius warreni},
	journal = {Agricultural and Forest Entomology},
	volume = {14},
	number = {3},
	year = {2012},
	month = {August},
	pages = {286-294},
	abstract = {1 Visual stimuli, often in combination with olfactory stimuli, are frequently important components of host selection by forest-dwelling phytophagous insects. 2 Warren root collar weevil Hylobius warreni Wood (Coleoptera: Curculionidae) is a native insect in western Canada, where larvae feed primarily on lodgepole pine Pinus contorta and can girdle and kill young trees. This weevil is an emerging problem in areas heavily impacted by mountain pine beetle Dendroctonus ponderosae Hopkins. 3 No olfactory attractants have been identified for this insect, making monitoring and management difficult. Thus, we investigated the role of vision in the host-finding behaviour of Warren root collar weevil in the absence of known olfactory cues. 4 We conducted three experiments in field enclosure plots aiming to characterize aspects of host-finding behaviour by adult Warren root collar weevil. 5 We found that both male and female weevils were readily attracted to vertical plastic silhouettes in the shape of a trunk, crown or tree at distances of less than 4 m. This pattern of attraction persisted over 2 years in two slightly different study designs. Blinding the insects removed their ability to orient to these silhouettes, indicating that host-finding behaviour has a strong visual component. The use of different colour trunks and crowns (black, white and green) did not change the patterns of attraction of the insects to the silhouettes. 6 Exploiting visual attraction in this walking insect may present a new management tool in forest protection strategies.},
	keywords = {Dendroctonus ponderosae},
	isbn = {1461-9555},
	author = {Machial, Laura A. and B.S. Lindgren and Aukema, Brian H.}
}
@article {14330,
	title = {Dispersal of Warren Root Collar Weevils (Coleoptera: Curculionidae) in Three Types of Habitat},
	journal = {Environmental Entomology},
	volume = {41},
	number = {3},
	year = {2012},
	month = {Jun},
	pages = {578-586},
	abstract = {Warren root collar weevil, Hylobius warreni Wood, is a native, flightless insect distributed throughout the boreal forest of North America. It is an emerging problem in young plantings of lodgepole pine, Pinus contorta variety latifolia, in western Canada, where larval feeding can kill young trees by girdling the root collar. Susceptible plantings are becoming more abundant following salvage harvesting and replanting activities in the wake of an ongoing epidemic of mountain pine beetle, Dendroctonus ponderosae (Hopkins). Previous studies using mark-trap-recapture methods found that movement rates of adult H. warreni were elevated in areas with high numbers of dead trees, consistent with a hypothesis that the insects immigrate from stands with high mountain pine beetle-caused tree mortality to young plantings in search of live hosts. Sampling methods were necessarily biased to insects captured in traps; however, potentially missing individuals that had died, left the study area, or simply remained stationary. Here, we used harmonic radar to examine weevil movement in three different habitats: open field, forest edge, and within a forest. We were able to reliably monitor all but two of 36 insects initially released, over 96 h (4 d). Weevils released in the open field had the highest rates of movement, followed by weevils released at the forest edge, then weevils released within the forest. Movement declined with decreasing ambient air temperature. Our results suggest that weevils tend to be relatively stationary in areas of live hosts, and hence may concentrate in a suitable area once such habitat is found.},
	keywords = {Hylobius warreni},
	isbn = {0046-225X},
	author = {Machial, Laura A. and B.S. Lindgren and Steenweg, Robin W. and Aukema, Brian H.}
}
@article {13792,
	title = {Take me to your leader: does early successional nonhost vegetation spatially inhibit Pissodes strobi (Coleoptera: Curculionidae)?},
	journal = {Environmental Entomology},
	volume = {38},
	number = {4},
	year = {2009},
	month = {August},
	pages = {1189-1196},
	abstract = {The spatial influences of host and nonhost trees and shrubs on the colonization patterns of white pine weevil Pissodes strobi (Peck) were studied within a stand of planted interior hybrid spruce (Picea glauca (Moench) Voss X Picea engelmannii (Parry) ex Engelm.). Planted spruce accounted for one third of all trees within the stand, whereas the remaining two thirds were comprised of early-successional nonhost vegetation, such as alder (Alnus spp.), paper birch (Betula papyrifera Marsh.), black cottonwood (Populus balsamifera ssp. trichocarpa (T. Ng.) Brayshaw), lodgepole pine I Pinus contorta (Dougl.) ex Loud.), trembling aspen (Populus tremuloides Michx), willow (Salix spp.), and Canadian buffaloberry (Shepherdia canadensis (L.) Nutt.). Unlike the spruce trees, nonhost vegetation in the stand was not uniformly distributed. Spatial point process models showed that Canadian buffaloberry, paper birch, black cottonwoood, and trembling aspen had negative associations with damage caused by the weevil, even though the density of the insects{\textquoteright} hosts in these areas did not change. Moreover, knowing the locations of these nonhost trees provided as much, or more, inference about the locations of weevil-attacked trees as knowing the locations of suitable or preferred host trees (i.e., those larger in size). Nonhost volatiles, the alteration of soil composition, and overstory shade are discussed as potential explanatory factors for the patterns observed. New research avenues are suggested to determine whether nonhost vegetation in early successional stands might be an additional tool in the management of these insects in commercially important forests.},
	keywords = {Pissodes strobi},
	isbn = {0046-225X},
	author = {Koopmans, Jordan M. and de la Giroday, Honey-Marie C. and B.S. Lindgren and Aukema, Brian H.}
}
@article {13480,
	title = {Management response to one insect pest may increase vulnerability to another},
	journal = {Journal of Applied Ecology},
	volume = {47},
	number = {3},
	year = {2010},
	month = {Jun},
	pages = {566-574},
	abstract = {1. Large-scale insect outbreaks provide an ideal system to examine the cascade of ecological effects of disturbance regimes across forested landscapes. A major outbreak of the mountain pine beetle Dendroctonus ponderosae continues to exert landscape-level mortality across forests of lodgepole pine Pinus contorta var. latifolia. in western Canada. This outbreak, exacerbated in part by fire suppression and climate change, has affected more than 14 million ha of merchantable forest. Salvage and reforestation efforts are currently underway at landscape-level scales. An emerging concern is the migration of Warren root collar weevil Hylobius warreni from stands with a reduced host pool, i.e. those with a high per cent of mature, dead lodgepole pine, into young, replanted stands, resulting in significant levels of mortality to juvenile trees. 2. The impact of Warren root collar weevil in stands of young trees (9-11 years of age) replanted after salvage harvesting was examined in nine cutblocks (areas delineated for commercial timber harvest, c. 1 km in diameter). All cutblocks, sampled across the central interior of British Columbia, were located next to unsalvaged, mature stands. 3. Field data and aerial surveys revealed higher tree mortality from Warren root collar weevils along cutblock perimeters adjacent to unsalvaged, mature stands. Mortality decreased with increasing distance from the edge of the cutblocks. Additional mortality along these gradients was associated with increasing per cent of pine in the mature stand; more-so if the pine was dead. Moreover, the gradient of mortality became more pronounced with time as mountain pine beetle had attacked the adjacent mature stands. Weevils attacked the largest trees within the replanted cutblocks. 4. These gradients of tree mortality suggest migration of Warren root collar weevils from unsalvaged mature stands into adjacent replanted forests most probably in search of food. 5. Synthesis and applications. This study demonstrates how a management response to a large insect outbreak, itself mediated by anthropogenic factors, can predispose reforested stands to additional, unanticipated threats from other insects. Reforestation strategies following outbreaks of mountain pine beetle may need to include harvesting larger salvage blocks to minimize edge effects and reduce mortality from Warren root collar weevils. Moreover, the inclusion of deciduous non-host tree stock in planting mixes might reduce insect movement and limit tree mortality because of Warren root collar weevils.},
	isbn = {0021-8901},
	author = {Klingenberg, Matthew D. and B.S. Lindgren and Gillingham, Michael P. and Aukema, Brian H.}
}
@article {13056,
	title = {Radar observation and aerial capture of mountain pine beetle, Dendroctonus ponderosae Hopk. (Coleoptera: Scolytidae) in flight above the forest canopy},
	journal = {Canadian Journal of Forest Research},
	volume = {38},
	number = {8},
	year = {2008},
	month = {August},
	pages = {2313-2327},
	type = {Article},
	abstract = {An outbreak of the mountain pine beetle (Dendroctonus ponderosae Hopk.) in central British Columbia, Canada, has reached an unprecedented size and intensity and has been spreading. The 2005 emergence and subsequent flight of mountain pine beetle was studied using direct observation of emergence, weather radar imagery, and aerial capture. To verify that the daytime, clear-air radar returns seen during this period were indeed generated by airborne mountain pine beetles, aerial sampling in the area covered by the radar was performed using a drogue capture net towed by a single-engine light aircraft. Results verify that airborne mountain pine beetles are being detected by the weather radar and that, during the emergence period, significant numbers of mountain pine beetles can be found at altitudes up to more than 800 m above the forest canopy. An estimate of transport distance indicates that mountain pine beetles in flight above the forest canopy may move 30-110akm[center dot]day-1. An estimate of the instantaneous density of mountain pine beetles in flight above the canopy on flight days in 2005 indicate a mean (maximum) density of 4950 (18 600) beetles[center dot]ha-1.},
	keywords = {Dendroctonus ponderosae},
	isbn = {0045-5067},
	author = {Jackson, Peter L. and Straussfogel, Dennis and B.S. Lindgren and Mitchell, Selina and Murphy, Brendan}
}
@article {12583,
	title = {Successful colonization, reproduction, and new generation emergence in live interior hybrid spruce Picea engelmannii x glauca by mountain pine beetle Dendroctonus ponderosae},
	journal = {Agricultural and Forest Entomology},
	volume = {11},
	number = {1},
	year = {2009},
	month = {February},
	pages = {83-89},
	abstract = {1 Although mountain pine beetle Dendroctonus ponderosae Hopkins are able to utilize most available Pinus spp. as hosts, successful colonization and reproduction in other hosts within the Pinaceae is rare.2 We observed successful reproduction of mountain pine beetle and emergence of new generation adults from interior hybrid spruce Picea engelmannii x glauca and compared a number of parameters related to colonization and reproductive success in spruce with nearby lodgepole pine Pinus contorta infested by mountain pine beetle.3 The results obtained indicate that reduced competition in spruce allowed mountain pine beetle parents that survived the colonization process to produce more offspring per pair than in more heavily-infested nearby pine.4 We also conducted an experiment in which 20 spruce and 20 lodgepole pines were baited with the aggregation pheromone of mountain pine beetle. Nineteen pines (95\%) and eight spruce (40\%) were attacked by mountain pine beetle, with eight (40\%) and three (15\%) mass-attacked, respectively.5 Successful attacks on nonhost trees during extreme epidemics may be one mechanism by which host shifts and subsequent speciation events have occurred in Dendroctonus spp. bark beetles.},
	keywords = {Dendroctonus ponderosae},
	isbn = {1461-9555},
	author = {Huber, Dezene P. W. and Aukema, Brian H. and Hodgkinson, Robert S. and B.S. Lindgren}
}
@article {11430,
	title = {Association of tree diameter with body size and lipid content of mountain pine beetles},
	journal = {Canadian Entomologist},
	volume = {144},
	number = {3},
	year = {2012},
	month = {Jun},
	pages = {467-477},
	abstract = {Host tree diameter is considered an important predictor of the population dynamics of the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), but the relationship between host tree diameter and beetle traits is unclear. The primary objective of this study was to determine how the quality of individual mountain pine beetles, measured as body size (pronotum width) and lipid content, varied with the diameter of lodgepole pine trees, Pinus contorta var. latifolia Engelmann (Pinaceae). Naturally attacked trees, ranging in diameter from 10 to 35 cm, were selected from stands near Prince George, British Columbia, Canada. Colonisation density and pupal density generally increased with tree diameter, but the number of pupal chambers per gallery start remained constant. Tree diameter positively affected beetle body size, which in turn was positively correlated with absolute lipid content in both sexes and relative lipid content in males. However, tree diameter did not directly predict absolute lipid content, and relative lipid content decreased with tree diameter in males. Larger beetles emerged earlier in the emergence period with relative lipid content remaining constant throughout emergence. All relationships had considerable unexplained variation. Thus, the use of tree diameter or emergence time as predictors of population dynamics of mountain pine beetles should be done with caution.},
	keywords = {Dendroctonus ponderosae},
	isbn = {0008-347X},
	author = {Graf, M. and Reid, M. L. and Aukema, B. H. and B.S. Lindgren}
}
@article {10617,
	title = {Incoming! Association of landscape features with dispersing mountain pine beetle populations during a range expansion event in western Canada},
	journal = {Landscape Ecology},
	volume = {26},
	number = {8},
	year = {2011},
	month = {Oct},
	pages = {1097-1110},
	abstract = {Mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae, Scolytinae), is a forest insect that undergoes intermittent population eruptions, causing landscape-level mortality to mature pines. Currently, an outbreak covers over 16.3 million ha of British Columbia and Alberta in western Canada. Recent incursion into the jack pine (Pinus banksiana Lamb.) of northwestern Alberta threatens further range expansion through the boreal forest to central and eastern Canada. The spread from British Columbia into northwestern Alberta has been facilitated by above-canopy dispersal of the insect by meso-scale atmospheric currents. At these scales, dispersing D. ponderosae may behave like inert particles, causing terrain-induced tropospheric convective and advective currents to influence population dispersal and establishment. We use spatial point process regression models to examine the association of meso-scale variables, including landscape features and their orientations, habitat suitability, elevation and treatment efforts, with occurrence of D. ponderosae infestations in 2004, 2005, and 2006. Infestations of D. ponderosae primarily established in canyons and valleys, before moving into more open-sloped areas. Southwestern slopes of midslope ridges and small hills, southwest facing open slopes, and valleys that run in a northeast-southwest cardinal direction were positively associated with higher intensities of infestation. This study provides insight into the influences of complex terrain on landscape disturbance by a forest insect, and can be used to prioritize areas for potential management.},
	keywords = {Dendroctonus ponderosae},
	isbn = {0921-2973},
	author = {de la Giroday, Honey-Marie C. and Carroll, Allan L. and B.S. Lindgren and Aukema, Brian H.}
}
@article {10559,
	title = {Climate change and range expansion of an aggressive bark beetle: evidence of higher beetle reproduction in naive host tree populations},
	journal = {Journal of Applied Ecology},
	volume = {47},
	number = {5},
	year = {2010},
	month = {Oct},
	pages = {1036-1043},
	abstract = {1. Hosts may evolve defences that make them less susceptible and suitable to herbivores impacting their fitness. Due to climate change-driven range expansion, herbivores are encountering naive host populations with increasing frequency. 2. Aggressive bark beetles are among the most important agents of disturbance in coniferous forest ecosystems. The presence of bark beetle outbreaks in areas with a historically unsuitable climate, in part a consequence of climate change, provided an opportunity to assess the hypothesis that the mountain pine beetle Dendroctonus ponderosae has higher reproductive success in lodgepole pine Pinus contorta trees growing in areas that have not previously experienced frequent outbreaks. 3. We felled and sampled mountain pine beetle-killed trees from historically climatically suitable and unsuitable areas, i.e. areas with and without a historical probability of frequent outbreaks. Reproductive success was determined from a total of 166 trees from 14 stands. 4. Brood productivity was significantly affected by climatic suitability class, such that mean brood production per female increased as historical climatic suitability decreased. 5. Synthesis and applications. The current study demonstrates that the mountain pine beetle has higher reproductive success in areas where its host trees have not experienced frequent beetle epidemics, which includes much of the current outbreak area in north central British Columbia. This increased productivity of mountain pine beetle is likely to have been a key reason for the rapid population buildup that resulted in unprecedented host tree mortality over huge areas in western Canada. The outbreak thus provides an example of how climate change-driven range expansion of native forest insects can have potentially disastrous consequences. Since an increased reproductive success is likely to accelerate the progression of outbreaks, it is particularly critical to manage forests for the maintenance of a mosaic of species and age classes at the landscape level in areas where host tree populations are naive to eruptive herbivores.},
	keywords = {Dendroctonus ponderosae},
	isbn = {0021-8901},
	author = {Cudmore, Timothy J. and Bjorklund, Niklas and Carroll, Allan L. and B.S. Lindgren}
}
@article {9401,
	title = {Diameter of lodgepole pine and mortality caused by the mountain pine beetle: factors that influence their relationship and applicability for susceptibility rating},
	journal = {Canadian Journal of Forest Research},
	volume = {39},
	number = {5},
	year = {2009},
	month = {May},
	pages = {908-916},
	abstract = {<p>During outbreaks the mountain pine beetle (Dendroctonus ponderosae Hopkins) kills large lodgepole pine trees (Pinus contorta Dougl. ex Loud.) more frequently than smaller ones. There is, however, considerable variation in the relation of diameter to incidence of attack. In a meta- analysis of published data we found that the relationship was primarily determined by geographic location (elevation, latitude, and longitude). We propose a new tree mortality measure, the probability of death index, defined as the average percentage of mortality for trees \&gt;23 cm. The index may improve the precision in predictive modeling of tree mortality, as it provides a biologically relevant measure of mortality, since it only includes trees that contribute to the growth of an epidemic and is not influenced by the number of trees within a diameter class. To be useful to forest managers, it must be possible to predict the index from stand parameters that are easily meas- ured. The usefulness of the index was supported by a meta- analysis, which showed that 53\% of the variation in the mortal- ity index was explained by geographic location. Tree density did not explain any additional variation. Future research is needed to evaluate the performance of the probability of death index compared with that of other mortality measures.</p>
},
	keywords = {Dendroctonus ponderosae},
	isbn = {0045-5067},
	author = {Bjorklund, Niklas},
	editor = {B.S. Lindgren}
}
@article {9402,
	title = {Can predicted mountain pine beetle net production be used to improve stand prioritization for management?},
	journal = {Forest Ecology and Management},
	volume = {257},
	number = {1},
	year = {2009},
	month = {January 20},
	pages = {233-237},
	abstract = {Stand-level planning of lodgepole pine management can benefit from the use of mountain pine beetle susceptibility-riskmodel analyses to assign treatment priority. Priority is currently assigned based solely on relative levels of expected volume loss in the event of a mountain pine beetle outbreak.We evaluated the possibility to predict the relative contribution of brood beetles, by infested stands, to the next beetle generation. Existing data were used to develop generalized parameters for inclusion in predictive models of stand-level mortality and brood production. Model output for independent stands achieved a highly significant relationship with measured outcomes of brood productivity, indicating that relative levels of brood production can be predicted and incorporated into decision-models.},
	keywords = {Dendroctonus ponderosae},
	isbn = {0378-1127},
	author = {Bjorklund, Niklas and B.S. Lindgren and Shore, Terry L. and Cudmore, Tim}
}
@article {5234,
	title = {Using genetic analyses to infer mountain pine beetle population structure and dispersal patterns in British Columbia and Alberta},
	journal = {British Columbia Journal of Ecosystems and Management},
	volume = {9},
	number = {3},
	year = {2009},
	month = {Winter},
	pages = {140-142},
	abstract = {The mountain pine beetle (mpb) is an eruptive insect that is currently causing an outbreak of record size in western Canada. The longstanding lack of long-distance mpb dispersal data has limited our understanding and management of mpb outbreaks. Our goal was to characterize the genetic structure of western Canadian mpb populations, from which dispersal patterns may be inferred. We analyzed 35 mpb stands in British Columbia and Alberta at six microsatellite loci. The mpb exhibited strong and significant population structure. This structure was partitioned into a Northern and Southern group. The genetic structure and observed patterns of diversity are consistent with the notion of post-glacial recolonization and climate-driven differences in mpb population dynamics. Using our genetic data, we inferred the historical movement patterns of the mpb in western Canada. We found no evidence that the infestation spread from an epicentre in Tweedsmuir Provincial Park. Our data support multiple sources for the current outbreak. Management recommendations are included.},
	isbn = {1488-4666},
	url = {http://www.forrex.org/jem/default.asp},
	author = {Bartell, Nicholas V. and B.S. Lindgren and Cooke, Janice and Davis, Corey and Mock, Karen and Murray, Brent W.}
}
