@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 {13479,
	title = {Seeing the Forest Through the Trees: Differential Dispersal of Hylobius warreni Within Modified Forest Habitats},
	journal = {Environmental Entomology},
	volume = {39},
	number = {3},
	year = {2010},
	month = {Jun},
	pages = {898-906},
	abstract = {Hylobius warreni Wood, also known as the Warren root collar weevil, is a flightless insect that feeds on conifers throughout the boreal forests of Canada. Mature trees typically can withstand feeding, but larval feeding around the root collar may cause mortality to young trees. Recently, a large outbreak of mountain pine beetle (Dendroctonus ponderosae Hopkins) has killed a high proportion of mature lodgepole pine (Pinus contorta Douglas variety latifolia) across British Columbia, Canada. This raises concerns that adult weevils may migrate from mature forests with reduced host pools into adjacent young forests that had been salvaged and replanted. To study movement of these walking weevils in different habitat types, we constructed three research plots consisting of various combinations of live-, dead-, and mixed (i.e., live and dead) -tree habitats. We observed dispersal patterns of individually labeled insects using a novel insect trap attached to the base of trees. Approximately 35\% of insects were recaptured over 1 mo. Weevils were least likely to be recaptured proximate to the release location when released in a habitat with dead trees. Movement rates therein were almost double the rates of insects moving through live- or mixed-tree habitats. Our findings support the hypothesis that H. warreni may disperse out of habitats with dead trees into areas with higher proportions of green trees. Our findings are discussed in the context of habitat discrimination and potential increases in herbivory by H. warreni in western Canada given salvage harvesting activities after outbreaks of mountain pine beetle.},
	keywords = {Hylobius warreni},
	isbn = {0046-225X},
	author = {Klingenberg, Matthew D. and Bjorklund, Niklas 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 {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 {12540,
	title = {Temptations of weevil: feeding and ovipositional behaviour of Hylobius warreni Wood on host and nonhost bark in laboratory bioassays},
	journal = {Agricultural and Forest Entomology},
	volume = {11},
	number = {4},
	year = {2009},
	month = {November},
	pages = {397-403},
	abstract = {Warren root collar weevil Hylobius warreni Wood (Coleoptera: Curculionidae) is a long-lived, flightless insect native to coniferous forests across northern North America. Girdling by larval feeding causes significant mortality on young trees. The insect poses considerable challenges to reforestation.Adult weevils feed on all life stages of a variety of coniferous hosts prior to oviposition. Their relative feeding preferences, however, have not been quantified. Moreover, it is not known whether host bark influences oviposition behaviour.Feeding preferences of adult weevils were tested in both choice and no-choice laboratory bioassays using small branches from three conifers (lodgepole pine Pinus contorta var. latifolia, interior hybrid spruce Picea glauca x engelmannii, and Douglas-fir Pseudotsuga menziesii) and one deciduous tree (trembling aspen Populus tremuloides). Measurements included the surface area of bark consumed, rate of consumption, the number of days of feeding, and, in the no-choice assay, the number of eggs oviposited.Bark consumption was greatest on pine and Douglas-fir, followed by spruce. Little to no feeding occurred on aspen. Consumption did not vary between male versus female insects for any of the feeding metrics quantified.The presence of aspen branches did not inhibit feeding on any of the other species in the choice bioassays.The number of eggs laid by female insects did not differ significantly among tree species in the no-choice assay. Eggs were laid indiscriminately in the presence of all four host types.Results and opportunities for future research are discussed in the context of formulating new integrated pest management strategies for this insect, which is increasingly important in the period of reforestation subsequent to the mountain pine beetle epidemic in western Canada.},
	keywords = {Hylobius warreni},
	isbn = {1461-9555},
	author = {Hopkins, Gareth R. and Klingenberg, Matthew D. and Aukema, Brian H.}
}
@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 {10616,
	title = {Breach of the northern Rocky Mountain geoclimatic barrier: initiation of range expansion by the mountain pine beetle},
	journal = {Journal of Biogeography},
	volume = {39},
	number = {6},
	year = {2012},
	month = {Jun},
	pages = {1112-1123},
	abstract = {Aim Our aim is to examine the historical breach of the geoclimatic barrier of the Rocky Mountains by the mountain pine beetle (Dendroctonus ponderosae Hopkins). This recent range expansion from west of the North American continental divide into the eastern boreal forest threatens to provide a conduit to naive pine hosts in eastern North America. We examine the initial expansion events and determine potential mechanism(s) of spread by comparing spread patterns in consecutive years to various dispersal hypotheses such as: (1) meso-scale atmospheric dispersal of insects from source populations south-west of the Rocky Mountains in British Columbia (i.e. their historical range), (2) anthropogenic transport of infested plant material, and (3) spread of insect populations across adjacent stands via corridors of suitable habitat. Location British Columbia, Canada. Methods We explore potential mechanism(s) of invasion of the mountain pine beetle using spatial point process models for the initial 3 years of landscape-level data collection, 2004-2006. Specifically, we examine observed patterns of infestation relative to covariates reflecting various dispersal hypotheses. We select the most parsimonious models for each of the initial 3 years of invasion using information criteria statistics. Results The initial range expansion and invasion of the beetle was characterized by aerial deposition along a strong north-west to south-east gradient, with additional aerial deposition and localized dispersal from persisting populations in following years. Main conclusions Following deposition of a wave front of mountain pine beetles parallel to the Rocky Mountains via meso-scale atmospheric dispersal, the areas of highest intensity of infestations advanced up to 25 km north-east towards jack pine (Pinus banksiana) habitat in a single year. There appeared to be no association between putative anthropogenic movement of infested materials and initial range expansion of the mountain pine beetle across the continental divide.},
	keywords = {Dendroctonus ponderosae},
	isbn = {0305-0270},
	author = {de la Giroday, Honey-Marie C. and Carroll, Allan L. and Aukema, Brian H.}
}
@article {9446,
	title = {Efficacy of tree defense physiology varies with bark beetle population density: a basis for positive feedback in eruptive species},
	journal = {Canadian Journal of Forest Research},
	volume = {41},
	number = {6},
	year = {2011},
	month = {Jun},
	pages = {1174-1188},
	abstract = {We evaluated the ability of constitutive and inducible defenses to protect trees and restrict herbivore reproduction across the endemic, incipient (i.e., transitory), and eruptive phases of a native bark beetle species. Host defenses were major constraints when mountain pine beetle (Dendroctonus ponderosae Hopkins) populations were low, but inconsequential after stand-level densities surpassed a critical threshold. We annually examined all lodgepole pines (Pinus contorta Douglas var. latifolia) in six 12-18 ha stands for 3-6 years for beetle attack and establishment as beetle densities progressed through various population phases. We also assayed a suite of tree physiological and chemical attributes and related them to subsequent attacks during that year. Rapidly inducible defenses appeared more important than constitutive defenses, and total monoterpenes were more important than particular constituents. Trees that exude more resin and accumulate higher monoterpene concentrations in response to simulated attack largely escaped natural attacks when populations were low. In stands where beetles had reached incipient densities, these defenses were ineffective. Larger diameter trees had more pronounced defenses than smaller diameter trees. As populations increased, beetles selected increasingly larger, more resource-rich trees, despite their better defenses. When populations were too low for cooperative attack, beetles exploited trees weakened by lower-stem insects. Behavioral plasticity allows beetles to persist at endemic levels until conditions shift, after which positive feedbacks predominate.},
	keywords = {Dendroctonus ponderosae},
	isbn = {0045-5067},
	author = {Boone, Celia K. and Aukema, Brian H. and Bohlmann, Joerg and Carroll, Allan L. and Raffa, Kenneth F.}
}
@article {9115,
	title = {Predisposition to bark beetle attack by root herbivores and associated pathogens: roles in forest decline, gap formation, and persistence of endemic bark beetle populations},
	journal = {Forest Ecology and Management},
	volume = {259},
	number = {3},
	year = {2010},
	month = {January 25},
	pages = {374-382},
	abstract = {Bark beetles are largely known for their ability to undergo intermittent population eruptions that transform entire landscapes and pose significant economic hardships. However, most species do not undergo outbreaks, and eruptive species usually exert only minor disturbances. Understanding the dynamics of tree-killing noneruptive species can provide insights into how beetles persist at low densities, and how some spatiotemporal patterns of host predisposition may more likely favor breaching eruptive thresholds than others. Elucidating mechanisms behind low-density populations is challenging, however, due to the requirement of long-term monitoring and high degrees of spatial and temporal covariance. We censused more than 2700 trees annually over 7 years, and at the end of 17 years, in a mature red pine plantation. Trees were measured for the presence of bark beetles and wood borers that breed within the primary stem, root weevils that breed in root collars, and bark beetles that breed in basal stems. We quantify the sequence of events that drive this decline syndrome, with the primary emergent pattern being an interaction between below- and above-ground herbivores and their fungal symbionts. This interaction results in an expanding forest gap, with subsequent colonization by early-successional vegetation. Spatial position strongly affects the likelihood of tree mortality. A red pine is initially very likely to avoid attack by tree-killing Ips beetles, but attack becomes increasingly likely as the belowground complex spreads to neighboring trees and eventually make trees susceptible. This system is largely internally driven, as there are strong gap edge, but not stand-edge, effects. Additional stressors, such as drought, can provide an intermittent source of susceptible trees to Ips beetles, and elevated temperature slightly accentuates this effect. New gaps can arise from such trees as they subsequently become epicenters for the full complex of organisms associated with this decline, but this is not common. As Ips populations rise, there is some element of positive feedback, in that the proportion of killed trees that were not first colonized by root organisms increases. This positive feedback is very weak, however, and we propose the slope between beetle population density and reliance on host stress as a quantitative distinction along a gradient from noneruptive through eruptive species. Almost all trees colonized by Ips were subsequently colonized by wood borers, likely a source of negative feedback. We discuss implications to our overall understanding of cross-scale interactions, between-guild interactions, forest declines, and eruptive thresholds. (C) 2009 Elsevier B.V. All rights reserved.},
	keywords = {Ips},
	isbn = {0378-1127},
	author = {Aukema, Brian H. and Zhu, Jun and Moller, Jesper and Rasmussen, Jakob G. and Raffa, Kenneth F.}
}
@article {9113,
	title = {Movement of outbreak populations of mountain pine beetle: influences of spatiotemporal patterns and climate},
	journal = {Ecography},
	volume = {31},
	number = {3},
	year = {2008},
	month = {June},
	pages = {348-358},
	type = {Article},
	abstract = {Insect outbreaks exert landscape-level influences, yet quantifying the relative contributions of various exogenous and endogenous factors that contribute to their pattern and spread remains elusive. We examine an outbreak of mountain pine beetle covering an 800 thousand ha area on the Chilcotin Plateau of British Columbia, Canada, during the 1970s and early 1980s. We present a model that incorporates the spatial and temporal arrangements of outbreaking insect populations, as well as various climatic factors that influence insect development. Onsets of eruptions of mountain pine beetle demonstrated landscape-level synchrony. On average, the presence of outbreaking populations was highly correlated with outbreaking populations within the nearest 18 km the same year and local populations within 6 km in the previous two years. After incorporating these spatial and temporal dependencies, we found that increasing temperatures contributed to explaining outbreak probabilities during this 15 yr outbreak. During collapse years, landscape-level synchrony declined while local synchrony values remained high, suggesting that in some areas host depletion was contributing to population decline. Model forecasts of outbreak propensity one year in advance at a 12 by 12 km scale provided 80\% accuracy over the landscape, and never underestimated the occurrence of locally outbreaking populations. This model provides a flexible approach for linking temperature and insect population dynamics to spatial spread, and complements existing decision support tools for resource managers.},
	keywords = {Dendroctonus ponderosae},
	isbn = {0906-7590},
	author = {Aukema, Brian H. and Carroll, Allan L. and Zheng, Yanbing and Zhu, Jun and Raffa, Kenneth F. and Moore, R. Dan and Stahl, Kerstin and Taylor, Stephen W.}
}
@article {9114,
	title = {Variation in Complex Semiochemical Signals Arising From Insects and Host Plants},
	journal = {Environmental Entomology},
	volume = {39},
	number = {3},
	year = {2010},
	month = {Jun},
	pages = {874-882},
	abstract = {Chemical communication by many insect species involves complex signals of both insect and plant origin. Much attention has been focused on the behavioral activities of these components but less on their sources of variation, despite implications for evolutionary theory and pest management. We studied variation in chemical signaling at host, tree-within-host, and beetle-on-tree scales using tunneling male pine engravers (Ips pini (Say)) on jack, Pinus banksiana Lamb, red, P. resinosa Aiton, and white, P. strobus L. pines. Pine engravers are distributed transcontinentally, and stereoisomeric ratios of their principal pheromone component ipsdienol varies regionally. Linear mixed-effects models were used to examine variation in monoterpene and pheromone volatile profiles, determined by gas chromatography. Phloem from white pine had the greatest concentration of monoterpenes, although insects tunneling in white pine produced the smallest ratios of monoterpenes to pheromones (1:2) in their volatile plumes relative to jack and red pine (1:1). Beetle-to-beetle variation in plume composition was [approximately equal]2-9 times greater than the inter-tree variation within a tree species. The stereoisomeric ratio of ipsdienol was highly consistent within the pheromone component of the plume. The little variation present existed almost entirely at the level of the insects. Within the pheromone component of the plume in a given host species, there was up to 13 times more beetle-to-beetle than tree-to-tree variation. This magnitude was almost double the magnitudes of the ratios among components within the entire plumes. Implications to the behavioral ecology of bark beetle communication, such as potential strategies of cheating and predator avoidance, are discussed.},
	isbn = {0046-225X},
	author = {Aukema, Brian H. and Powell, Jaimie S. and Clayton, Murray K. and Raffa, Kenneth F.}
}
@article {5964,
	title = {Autologistic regression analysis of spatial-temporal binary data via Monte Carlo maximum likelihood},
	journal = {Journal of Agricultural Biological and Environmental Statistics},
	volume = {13},
	number = {1},
	year = {2008},
	month = {March},
	pages = {84-98},
	type = {Article},
	abstract = {This article considers logistic regression analysis of binary data that are measured on a spatial lattice and repeatedly over discrete time points. We propose a spatial-temporal autologistic regression model and draw statistical inference via maximum likelihood. Due to an unknown normalizing constant in the likelihood function, we use Monte Carlo to obtain maximum likelihood estimates of the model parameters and predictive distributions at future time points. We also use path sampling to estimate the unknown normalizing constant and approximate an information criterion for model assessment. The methodology is illustrated by the analysis of a dataset of mountain pine beetle outbreaks in western Canada.},
	keywords = {Dendroctonus ponderosae},
	isbn = {1085-7117},
	author = {Zhu, Jun and Zheng, Yanbing and Carroll, Allan L. and Aukema, Brian H.}
}
