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Validation of models of Land Use and Cover Change often involves comparing maps of simulated and reference change. The interpretation of differences between simulated and reference change depends on the characteristics of the process being studied. Our paper focuses on validation of models of one-way land change processes that spread in space. Our objective is to develop a method for validation of one-way land change models, such that the method provides objective information about the spatial distribution of errors. Using distance analysis on reference data, we build a baseline model for comparison with simulations. We then simultaneously compare the four maps of reference at initial time, reference at final time, simulation at final time, and baseline at final time. We also use Total Operating Characteristic curves and multiple-resolution map comparison. We illustrate the methods with a simulation of forest insect infestations. The methods give insights concerning the reference data and the spatial distribution of misses, hits, and false alarms with respect to initial points of infestations. The new methods reveal that the simulations underestimated change near initial points of spread. The spatial distribution of errors is a topic of land change models that deserves attention. For models of one-way, geographically-spreading processes, we recommend that validation should distinguish between near and far allocation errors with respect to initial points of spread.

Chemical control is widely used to control the Japanese pine sawyer beetle, Monochamus alternatus, but strong chemical regulations require an environmentally sound management strategy. In this work, we investigated the use of entomopathogenic fungi and their application as a means of practical pest management. Thirty-two diverse species of fungal isolates were assayed against adult pine sawyer beetles using a contact method under laboratory conditions, and four isolates showed over 70% virulence consequently. These isolates, two each of Beauveria bassiana and Metarhizium anisopliae were sprayed on the adult beetles at 1 × 107 conidia/ml in plastic containers, respectively. The M. anisopliae-treated adult beetles showed 67% mortality. M. anisopliae isolates JEF-197 and JEF-279 demonstrated dosage-dependent insecticidal activity. Following the laboratory experiments, semi-field trials were conducted in young pine trees under high (RH 94%) and low (RH 35%) humidity conditions. In the high humidity conditions, most of the adult beetles stayed on the top of the branches. When the two M. anisopliae isolates were sprayed on the beetles, they showed ca. 50–70% insecticidal activity 11 days after application. In contrast, in low humidity conditions, the adult beetles tried to move off the branches and onto the soil. When the beetles reached the JEF-197 and JEF-279-treated soil, we measured >90% insecticidal activity. This work suggests that M. anisopliae was the most virulent entomopathogenic fungus against adult Japanese pine sawyer beetles, and this forest insect could be ecologically controlled by the spray and soil application of the M. anisopliae isolates.

A growing body of work exists on the social implications of forest insect disturbances. However, although increasingly explored, there remains a need to further understand social responses to large...

Emerald ash borer (EAB), an invasive forest insect from Asia, has impacted vast areas in the United States and European Russia. To proactively understand the social impact of an EAB invasion in Europe and the USA, this study analyzed visitors’ preferences and preference heterogeneity for EAB-impacted forest scenarios in Vienna, Austria (n = 510) and Minneapolis, USA (n = 307). An image-based discrete choice experiment with latent-class analysis among on-site completed questionnaires in Vienna indicated four different visitor segments based on trade-offs among biophysical, social and viewscape elements. Within the forested environment, two segments placed greater importance on (bio)physical attributes and two on social aspects. Although all segments preferred a non-impacted ash forest, only one of the four identified the attribute describing EAB impacts and forest management as the most important attribute. Rather, visitor numbers and background viewscapes were more important than EAB impact and management to differentiate landscape preferences for three of the four segments. Differences in preferences were found between the Vienna and Minneapolis samples. Vienna respondents showed a higher preference for more natural conditions, disliked more the initial stage of EAB impact and placed more importance on background viewscapes and visitor numbers. Forest managers and greenspace planners need to consider the entirety of the forested condition, social and visual, for effective management and address that visitors differ in their preferences for all of these conditions.

Environmental change is altering forest insect dynamics worldwide. As these systems change, they pose significant ecological, social, and economic risk through, for example, the loss of valuable habitat, green space, and timber. Our understanding of such systems is often limited by the complexity of multiple interacting taxa. As a consequence, studies assessing the ecology, physiology, and genomics of each key organism in such systems are increasingly important for developing appropriate management strategies. Here we summarize the genetic and genomic contributions made by the TRIA project — a long-term study of the mountain pine beetle (Dendroctonus ponderosae Hopkins) system encompassing beetle, fungi, and pine. Contributions include genetic and genomic resources for species identification, sex determination, detection of selection, functional genetic analysis, mating system confirmation, hybrid stability tests, and integrated genetic studies of multiple taxa. These resources and subsequent findings have accelerated our understanding of the mountain pine beetle system, facilitating improved management strategies (e.g., enhancements to stand susceptibility indices and predictive models) and highlighting mechanisms for promoting resilient forests. Further, work from the TRIA project serves as a model for the increasing number and severity of invasive and native forest insect outbreaks globally (e.g., Dutch elm disease and thousand cankers disease).

The problem of forest insect invasions is intensifying. Non-native forest insects are invading virtually every world region, and many are causing severe ecological and economic impacts. Biosecurity programs provide for intervention at various stages of the invasion process in order to mitigate the invasion problem. While preventing initial arrival of non-native insect species is a sound approach, such prevention is not always possible so additional measures are needed to manage invasions. Surveillance coupled with eradication is a valuable strategy for preventing the establishment of many new and potentially damaging species. Once non-native species are established, containment measures can be implemented to stop or slow the spread of these species in their non-native habitat. Here, we review how eradication and containment can be carried out as strategies for managing forest insect invasions. Several hundred programs have been implemented to eradicate non-native forest insects, with most programs proving successful. The vast majority of these eradication programs were implemented from 1970 onward. Pheromone-baited traps play a key role for detection and delimitation in most successful eradication programs. The isolation and synthesis of pheromones provided a key technology that facilitated forest insect eradications starting in the 1970s. Several examples are provided that illustrate both successful and failed eradication and containment programs. Consideration of historical experiences suggests the conditions that may lead to either success or failure of eradication and containment efforts.

Spatial synchrony and cycles are common features of forest insect pests, but are often studied as separate phenomenon. Using time series of timber damage caused by Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae) (southern pine beetle) in 10 states within the southern United States, this study examines synchrony in D. frontalis abundance, the synchronizing effects of temperature extremes, and the evidence for shared cycles among state populations. Cross-correlation and cluster analyses are used to quantify synchrony across a range of geographic distances and to identify groups of states with synchronous dynamics. Similar techniques are used to quantify spatial synchrony in temperature extremes and to examine their relationship to D. frontalis fluctuations. Cross-wavelet analysis is then used to examine pairs of time series for shared cycles. These analyses suggest there is substantial synchrony among states in D. frontalis fluctuations, and there are regional groups of states with similar dynamics. Synchrony in D. frontalis fluctuations also appears related to spatial synchrony in summer and winter temperature extremes. The cross-wavelet results suggest that D. frontalis dynamics may differ among regions and are not stationary. Significant oscillations were present in some states over certain time intervals, suggesting an endogenous feedback mechanism. Management of D. frontalis outbreaks could potentially benefit from a multistate regional approach because populations are synchronous on this level. Extreme summer temperatures are likely to become the most important synchronizing agent due to climate change.

Higher temperatures projected under current climate change models are generally predicted to exert an overall positive effect on the success of invasive insects through increased survivability, developmental rates and fecundity, and by facilitating geographic range expansion. However, these effects have primarily focused on the shifts in winter temperatures with limited attention to the role that summer heat may play in shaping species ranges or fitness. We examined the thermal ecology of an ecologically important invasive forest insect, the hemlock woolly adelgid (Adelges tsugae), by determining survival during its summer dormancy phase under increasing temperature regimens. From laboratory and field experiments, we documented a positive association between increased temperatures and duration of exposure, and A. tsugae mortality. Adelges tsugae mortality was minimal ( 30 °C). At the warmest, southernmost edge of their range, field mortality of A. tsugae ranged from 8.5 to 81.9% and was strongly correlated with site temperature regimens. Further, we found no significant differences in A. tsugae survival between populations collected from Maine and Georgia, and over a 3-year period within Georgia, indicating that A. tsugae may not be acclimating to heat. These results highlight the importance of including summer temperatures in studies regarding increased temperatures on insect dynamics, and may alter historical predictions of climate change impacts on invasive insects and the conservation of forest ecosystems.

Commercial tree plantations cover around a million ha in Uruguay, mostly with stands of eucalypt and pine trees. Uruguayan forestry was free of serious insect pest until the end of the twentieth century. Beginning in the 1990s, both forestry area and international trade experienced an exponential growth, followed by an increase of invasive insect records. More than half of the pests currently affecting Eucalyptus entered the country after 1995. The use of pesticides is greatly restricted, provided around 90% of the plantations are under FSC and/or PEFC certification schemes. Hence, the Uruguayan forestry has relied mainly on silvicultural and biological control to suppress insect pest populations. Biological control for forest insect pests in Uruguay can be tracked back to 1941. Currently, biological control with entomophagous or entomopathogenic organisms has been, or is currently being, implemented for eight insect pests in plantations in Uruguay. More than five parasitoid wasps and a nematode have been released and installed in the field. There are also at least two cases of introduction of entomophagous organisms simultaneously with the pest. I discuss the future of biological control in Uruguay, focusing on the advantages it possesses and the challenges it faces under the current pest status.

Invasions by nonnative forest insects constitute a major threat to the sustainability of natural forest ecosystems. While most nonnative forest insects have had relatively minor effects, a small proportion of these species have had catastrophic impacts, altering ecosystem processes into the extended future. Over the last century, numbers of invasions have steadily increased, and presently, the majority of forest insect problems are the result of invasions. Given trends of increasing global trade, this problem is likely to expand. Increased resources and efforts to reduce arrival rates of nonnative insects, to intensify early detection and eradication, and to slow the spread of established invaders will be needed in the future.

Outbreaks of insect pests periodically cause large losses of volume in Canada’s forests. Compounded with climate change, outbreaks create significant challenges for managing the sustainable delivery of ecosystem services. Current methods to monitor damage by these pests involve both field and aerial surveys. While relatively cost effective and timely, aerial survey consistency and spatial coverage may be insufficient for detailed monitoring across Canada’s vast forest-land base. Remote sensing can augment these methods and extend monitoring capabilities in time and space by incorporating knowledge of pest-host interactions and of how damage translates into a remote sensing signal for detection and mapping. This review provides a brief introduction to major forest insect pests in Canada (two bark beetles (Coleoptera: Curculionidae) and six defoliators) and the damage they cause, a synthesis of the literature involving aerial survey and remote sensing, and a discussion of how these two approaches could be integrated into future pest monitoring from a Canadian perspective. We offer some lessons learned, outline roles that remote sensing could serve in a management context, and discuss what ongoing and upcoming technological advances may offer to future forest health monitoring.

With global warming, recent winters in Switzerland have been milder than in previous decades, and this trend is predicted to continue. Survival during the cold season could increase for insect species sensitive to winter cold events. Forest pests, such as the pine processionary moth (Thaumetopoea pityocampa) and green spruce aphid (Elatobium abietinum), as well as some crop pests, such as the southern green stink bug (Nezara viridula), could overwinter more easily. These species are affected by temperatures below –12°C or below –8°C. In this study, we examined whether changes in winter minimum temperatures (Tmin) could potentially favour the winter survival of these pest species in various places in Switzerland. We analysed long-term daily Tmin data from the period 1980–2019 at 67 locations. We then used two climatic scenarios (RCP2.6 and RCP8.5) to analyse daily Tmin in 2020–2099. We determined the number of days with Tmin below –8°C or –12°C and the frequency of years with at least one day below these thresholds. Our results show that the frequency of cold days has decreased over the last 40 years, even though winter Tmin has increased less than yearly Tmin. However, the –8°C threshold was still reached in most years, except on the Southern side of the Alps. The –12°C threshold was reached almost every year above 800 m, but infrequently at lower elevations. Our results indicate that, by the end of the 21st century, temperatures below –12°C will occur only infrequently up to 1700 m in Switzerland, and years with occurrences of temperatures below –8°C will become rare at lower elevations. Future temperature conditions can thus be expected to favour some crop pests, by enabling them to overwinter more easily on the Swiss Plateau, as well as some forest pests, which will likely reach higher elevations.

Insect identification has the disadvantage that it is difficult for non-experts to carry out due to the specificity of insects. Therefore, it is necessary for the general user to use auxiliary tools such as books to identify insects for education such as ecological learning. In recent years, researches using Deep Learning in fields such as object detection, behavior recognition, voice recognition as well as cancer detection in medical field have been actively conducted and show excellent results. In this paper, we developed a classification application that can be used in mobile phones with high automation and portability to solve the above insect classification problems. Experiments were conducted on 30 insect species selected for observable insects irrespective of environmental factors such as habitat and season, and the transform learning were applied to ResNet, which showed excellent performance in ILSVRC to classify forest insect. Our system achieved an average insect classification accuracy of 94%, an insect classification speed of 0.03 sec, and an insect photo transmission of 0.5 sec to output this information. This has proven that non-experts provide the appropriate performance to use.

Financial support was provided by the Department of Science and Technology (DST)/National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology. This project was supported by multiple grants from the NRF, South Africa, including the grant specific unique reference number (UID) 83924.

Canada is host to a number of native and introduced forest insects that negatively affect the goods and services provided by forests. Some insects affect forests on a fairly predictable, ongoing basis, while others have impacts that are intermittent, difficult to predict, and sometimes catastrophic. Economic analysis has provided important insights that have informed our understanding of the impact of forest pests and pest management. At the same time, interactions between forests, forest insects, forest management, and economic welfare are complex, and credible assessments may be time consuming and may not always provide results with the certainty sought by policy-makers. This paper reviews the contribution of economics to forest pest management in Canada and suggests future directions for this important field of research.

Insects use semiochemicals to mediate important behaviours such as mating, oviposition, and foraging for resources. Chemical ecology research aims to identify these message-bearing chemicals and develop synthetic copies of semiochemicals for use in integrated pest management (IPM). There has been, and continues to be, an extensive research effort to understand the chemical ecology of various insects considered to be pests of forests in Canada. Canadian chemical ecology research has had an impact on IPM of forest insect pests in Canada and around the world. Canadian researchers have been involved in the identification of semiochemicals used by forest insects and the development and implementation of semiochemical-based management tactics for forest pest management. Semiochemicals have been incorporated into forest pest management for a variety of insect taxa primarily as tools to monitor and control forest insect pests in Canada. The goals of the current review are to: (1) highlight research conducted on semiochemical-based management of forest pests in Canada; (2) discuss the current and potential uses of semiochemicals in IPM of forest pests in Canada; and (3) evaluate potential areas for increased research and implementation of semiochemicals into the management of forest pests in Canada.

The ability of insect pathogens (in particular viruses) to cause long-term stable limit cycles in their hosts was first demonstrated theoretically by Anderson and May (1980, 1981). Since then, there has been extensive discussion and controversy about whether the cycles seen in temperate forest insects (Varley 1949; Baltensweiler 1964; Baltensweiler et al. 1977) are caused by pathogens (Myers 1988) and whether the addition of greater biological detail to the simple Anderson and May model increases or decreases the likelihood of cycles. The Anderson and May model is a set of coupled ordinary differential equations, related to the Lotka-Volterra predator-prey model, in which neither the host nor the pathogen shows any density-dependent self-regulation. Since the type of forest insect that shows long-term cycles frequently severely depletes its food supply, it is natural to ask whether the addition of host selfregulation makes cycles more likely. This was first done by Bowers et al. (1993), who concluded that density dependence was unlikely to increase the probability of population cycles, although the opposite conclusion was reached the following year by Dwyer (1994). The apparent contradiction was reconciled by White et al. (1996), who showed that the two studies had incorporated host self

Carbaryl is regarded among the most effective, economically viable, and ecologically-compatible insecticides available for protecting conifers from bark beetle attack in the western United States. Treatments are typically applied in spring prior to initiation of bark beetle flight for that year. We evaluated the efficacy of spring and fall applications for protecting individual lodgepole pine, Pinus contorta Dougl. ex Loud, from mortality attributed to mountain pine beetle, Dendroctonus ponderosae Hopkins, the most notable forest insect pest in western North America. Both spring and fall treatments of 2.0% a.i. carbaryl (Sevin ® SL) were efficacious for two field seasons, while results from a third field season were inconclusive due to insufficient beetle pressure. We discuss the implications of these and other results to the management of D . ponderosae .

Emerald ash borer (EAB) (Agrilus planipennis Fairmaire), the most destructive forest insect to have invaded North America, has killed hundreds of millions of forest and landscape ash (Fraxinus spp.) trees. Several artificial trap designs to attract and capture EAB beetles have been developed to detect, delineate, and monitor infestations. Double-decker (DD) traps consist of two corrugated plastic prisms, one green and one purple, attached to a 3 m tall polyvinyl chloride (PVC) pipe supported by a t-post. The green prism at the top of the PVC pipe is baited with cis-3-hexenol, a compound produced by ash foliage. Surfaces of both prisms are coated with sticky insect glue to capture adult EAB beetles. Double-decker traps should be placed near ash trees but in open areas, exposed to sun. Double-decker trap construction and placement are presented here, along with a summary of field experiments demonstrating the efficacy of DD traps in capturing EAB beetles. In a recent study in sites with relatively low EAB densities, double-decker traps captured significantly more EAB than green or purple prism traps or green funnel traps, all of which are designed to be suspended from a branch in the canopy of ash trees. A greater percentage of double decker traps were positive, i.e., captured at least one EAB, than the prism traps or funnel traps that were hung in ash tree canopies.

Forest pests are one of the most important factors disturbing forest ecosystems, by impacting forestry economy, ecosystem services, biodiversity, and sustainable ecosystem management. Monitoring the occurrence of forest pests offers clues to understand their impacts on the forest ecosystem and develop a sustainable ecosystem management strategy. This special issue is designed to create a better understanding of the changes and impacts of forest pests according to forest changes, caused by natural or anthropogenic causes. There are 13 papers published in this special issue, covering several issues concerning forest pests. Two of the papers reviewed the changes in forest pests in Korea or Poland. The remaining twelve papers covered issues concerning the monitoring, assessment, and management of forest pests. Through this special issue, we expect to contribute towards the improvement of our knowledge of the structures and processes in forest ecosystems relating to forest pests and fundamental information for the effective management of forest pests.

Detection of newly established populations of Agrilus planipennis Fairmaire, the most destructive forest insect to invade the United States, remains challenging. Regulatory agencies currently rely on artificial traps, consisting of baited three-sided panels suspended in the canopy of ash (Fraxinus spp.) trees. Detection trees represent another survey option. Ash trees are girdled in spring to attract ovipositing A. planipennis females then debarked in fall to assess larval presence and density. From 2008-2010, systematic grids of detection trees and artificial traps were established across a 390-km(2) area for the SLow Ash Mortality pilot project. We compared probabilities of detection associated with detection trees and artificial traps along varying A. planipennis density proxies estimated as distance-weighted averages of larval counts (detection trees) or adult captures (traps) within 800 m of each detection tree or trap. Detection trees were consistently more likely to be positive, that is, detect A. planipennis, than traps in all three years, even when traps were placed in canopies of detection trees. Probability of detection with a single detection tree was >50% when density proxies for the area were

Forest dependent people, Incessant poverty in India, Forest insect sector, Institutional linkages, Conservation of insect biodiversity In India, forest based insect enterprises has never been linked up with any forest management activity, either as a forest conservation strategy or to reduce the poverty in forested area. This investigation indicated that when forest dependent people are associated with forest insect industry (FII) like forest sericulture, lac culture or apiculture; this income generating activity links livelihood with forest conservation, and generates a viable model of collaborative forest management (CFM). In this model different stakeholders work together as a coherent entity for unified goal of managing the forest for well-being of the poor people in fringe areas. Article summaries and evaluates the prospect of India specific forest insect industry, and discusses how and to what extent integration of FII could be a viable livelihood component in CFM to conserve the forest and insect biodiversity. We analysed a case study on forestbased rearing of tropical tasar silkworm rearing in Central India from CFM perspective. Arguments in this communication are intended to provide forest managers and policy-makers with necessary input to consider location specific FII in CFM mode to provide a continuous source of small income to forest dependent people to ensure long lasting success of their forest management endeavours.

The paper is concerned with the investigation of the model of dynamics of population of caterpillar budworm (Choristoneura fumiferana). The system solutions behavior depending on the parameters values has been investigated, conditions of origination of canard curves have been found.

Model testing procedures represent a major challenge in the development of agent-based models (ABMs). However, they are required stages for a model to be accepted and to serve as a forecasting, management or decision-making tool. This study presents a comprehensive approach for testing ForestSimMPB, an agent-based model (ABM) designed to simulate mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, outbreaks at the scale of individual trees. ForestSimMPB is a complex system model that is using swarming intelligence, capable to represent individuals’ behaviours and spatial interactions that influence their surrounding environment. Swarm Intelligence (SI) methods are integrated into the ABM in order to reproduce the collective reasoning and indirect communication of autonomous agents representing MPB behaviour within the forest environment. Model testing approach consist of verification, calibration, sensitivity analysis, validation and qualification stages. Model testing is accomplished by simulating MPB infestations using both the ForestSimMPB model and a Random–ABM model that serves as a null model. Outcomes comparison and assessment are performed using raster-based techniques as well as spatial metrics. Aerial photographs of the British Columbia, Canada study sites are used in this model testing approach. Results indicate that ForestSimMPB model representations of MPB outbreaks are more similar than Random model representations to the spatial distribution of MPB-dead trees.

The forest tent caterpillar (Malacosoma disstria Hbn.) is an eruptive forest insect common across North America and an important defoliator of trembling aspen (Populus tremuloides Michx.). Forest stands having suffered severe defoliations by the forest tent caterpillar over multiple years are known to incur reduced tree growth and increased tree mortality. In this study, we developed a predictive model of forest tent caterpillar defoliation dynamics using local and contextual variables expressing forest composition and structure, and their heterogeneity, at different scales. Of all scales considered (500, 1000, 1500, and 2000 m), contextual variables at 1500 m were found to have the greatest effect on defoliation dynamics. At this scale, we found that a greater proportion of preferred host trees in the landscape increased defoliation severity, but duration was modulated by compositional heterogeneity, where persistence was reduced in highly heterogeneous landscapes. Indeed, the likelihood of a single year of defoliation was much greater in highly diverse landscapes than the likelihood of multiple years of defoliation. These findings are consistent with ecological theory. Contrary to the expected result that older trees would be most susceptible, we found that “middle-aged” trees (~50 years) were most likely to be defoliated.

Our ability to understand the dynamics of forest insect outbreaks is limited by the lack of long-term data describing the temporal and spatial trends of outbreaks, the size and long life span of host plants, and the impracticability of manipulative experiments at relevant temporal and spatial scales. Population responses can be studied across varying site and stand conditions, or for a few years under somewhat controlled circumstances, but it is difficult to study temporal variability for species that outbreak only two or three times a century. Fortunately, dendrochronology enables us to explore decadal- and century-scale outbreak dynamics at spatial scales ranging from within-tree to continental. Evidence of past insect defoliation can be identified, dated, and sometimes quantified using variation in the width and morphology of annual growth rings in trees (Plate 7.1). Mortality events can be identified and dated by dating the last growth ring on dead trees, growth release events in survivors, and postdisturbance recruitment events. Insect defoliation can be distinguished from weather and other disturbance agents by comparing responses in host and nonhost trees.

Based on the fundamental meaning of Geographic Information System (GIS), the important features of GE Smallworld and the fundamental features of Forest Resources, we discuss the current application in forest resources information management, forest insect pest and disease control, the integration between GPS (global positioning system) and RS (remote sensing), resource management in nature reserve. At the same time the further development of GE Smallworld in forest resources management has been analyzed.

Understanding perceptions of risks, awareness, and trust in management agencies is critical to effective management of large-scale forest insect disturbance. In this study, we examined regional variation in public perceptions of risk, compared public and land managers’ perceptions, and examined knowledge and trust as factors in shaping public perceptions of a mountain pine beetle (MPB) ( Dendroctonus ponderosae Hopkins) infestation. Survey data were collected from residents (n = 1303) in three regions of Alberta and from land managers (n = 43) responsible for MPB management. Results showed that residents had moderate or great concern for MBP risks, they were not well informed about MPB, and they showed slight trust in the provincial government and forest industry to manage the beetle. There was regional variation in perceptions of risks, knowledge, and trust. Land managers were less concerned about nontimber effects and had higher trust than the public. A positive correlation between trust and risk perceptions appears to contradict the risk literature. This relationship may be influenced by an intervening effect of knowledge. These results call for more attention to the content of risk messaging and the effects of trust and knowledge on the general public who take up these messages.

A decision support system (DSS) for improved management decision making and to reduce impacts of forest insect outbreaks was developed and implemented for two defoliators, hemlock looper (Lambdina fiscellaria fiscellaria Guen.) and balsam fir sawfly (Neodiprion abietis Harris), in District 15, a 336,805 ha forest managed by Corner Brook Pulp and Paper Ltd. in western Newfoundland, Canada. Over the past 15 years, 56% and 12% of the landbase were defoliated by balsam fir sawfly and hemlock looper, which had major effects on forest growth and yield. Relationships between reduced growth and survival and cumulative defoliation were quantified for each insect, to permit calculation of relative impact per forest stand as a function of defoliation, stand age, and species composition. These were integrated into a forest estate model to project effects on timber supply for 25 years. Defoliation during 1996–2008 was estimated to reduce total operable softwood growing stock and softwood harvest level by 26% and 31%, respectively, for balsam fir sawfly, and by 2–3% for the smaller-scale hemlock looper outbreaks. Given the long-term influence on forest structure, effects of defoliation on yield were projected to continue for up to 60 years after defoliation ceased. Sensitivity analysis using different defoliation scenarios suggested that maximum reductions in harvest levels could be reduced from 40% to 17% by protecting the most susceptible 25% of the landbase using biological insecticides, and minimized further to 9% by re-optimization of harvest schedules to reduce losses. This DSS provides a tool to help forest managers decide when and where to use biological insecticides, and how to use rescheduling of harvest, forest restructuring or planned salvage to reduce future losses.

Aerial surveys provide valuable information on the scale and severity of defoliation and mortality caused by forest insects. However, methods to estimate the losses in growth using aerial survey data are not available. This study presents a method to link aerial survey data of location and severity of insect defoliation to tree ring series of radial growth in order to quantify potential growth losses due to defoliation. The method includes estimation of potentially confounding effects of climate. As an example we used aerial surveys of hemlock looper defoliation in the Mt. Revelstoke region of British Columbia, and tree ring series of radial growth of 351 western hemlock trees located in 22 plots and exposed to various levels of periodic defoliation. An autoregressive conditional heteroskedasticity time-series model (ARCH) of standardized growth indices identified significant direct and lagged effects of climate and defoliation on radial growth between 1930 and 2005. Defoliation effects were statistically significant in all plots (P < 0.05). The variation in both timing and strength of estimated growth reductions varied considerably among plots. During years of observed defoliation the radial growth was reduced by an average of 10%. Growth reductions attributed to defoliation were most pronounced in the second and third year of a looper outbreak. Our modelling approach linked tree ring data to aerial survey data of defoliation through a logistic distance dependent threshold function and affords a quantitative estimation of regional growth losses.

An analysis of forest tent caterpillar Malacosoma disstria defoliation records from Ontario and Quebec over the period 1938–2002 indicates that outbreaks recur periodically and somewhat synchronously among regions of the two provinces. Cluster analysis revealed that the most strongly periodic, large-scale, synchronized fluctuations occurred within three regions: northwestern Ontario, eastern Ontario/western Quebec and southeastern Quebec. Defoliation in the vast surrounding hinterlands tended to be infrequent and sporadic, loosely tracking defoliation in the core outbreak regions. One small cluster in northeastern Ontario stood out as anomalous, as a result of an increasing trend in the duration of periodic defoliation episodes, marked by an unprecedented double-wave of defoliation that persisted from 1992 to 1999. This is the precise area where, in the early 2000s, trembling aspen Populus tremuloides stems were mapped as being in a state of decline of unprecedented severity and extent. Our results suggest forest tent caterpillar has the potential to cause significant impacts on forest health and, hence, carbon budgets in east-central Canada and that the forest tent caterpillar deserves more attention as a model system of forest insect disturbance ecology.

Long-distance introductions of new invasive species have often been driven by socioeconomic factors, such that traditional “biological” invasion models may not be capable of estimating spread fully and reliably. In this study we present a new methodology to characterize and predict pathways of human-assisted entries of alien forest insects. We have developed a stochastic quantitative model of how these species may be moved with commodity flow through a network of international marine ports and major transportation corridors in Canada. The study makes use of a Canadian roadside survey database and data on Canadian marine imports, complemented with geo-referenced information on ports of entry, populated places and empirical observations of historical spread rates for invasive pests. The model is formulated as a probabilistic pathway matrix, and allows for quantitative characterization of likelihoods and vectors of new pest introductions from already or likely-to-be infested locations. We applied the pathway model to estimate the rates of human-assisted entry of alien forest insect species across Canada as well as cross-border transport to locations in the US. Results suggest a relatively low nationwide entry rate for Canada when compared to the US (0.338 new forest insect species per year vs. 1.89). Among Canadian urban areas, Greater Toronto and Greater Vancouver appear to have the highest alien forest insect entry potential, exhibiting species entry rates that are comparable with estimated rates at mid-size US urban metropolises.

This study estimates the social benefits of controlling two very different forest insect outbreaks in New Brunswick (NB) and Saskatchewan (SK), namely spruce budworm (SBW) (Choristoneura fumiferana) and forest tent caterpillar (FTC) (Malacosoma disstria). Using dichotomous choice contingent valuation mail surveys, households in NB and SK were asked to indicate their willingness-to-pay (WTP) for controlling future SBW and FTC outbreaks. A majority of respondents (over 80% in each province) favored controlling outbreaks of these insects. In both provinces, respondents were on average willing to pay more for controlling SBW outbreaks compared to FTC outbreaks. Aggregate social benefits (measured via compensating surplus) associated with proposed insect control programs in NB resulted in annual social benefits of $14.3–20.8 million for SBW control, and $7.9–14.5 million for FTC control. Comparable net benefits in SK were $22.2–32.4 million for SBW control, and $11.7–22.0 million for FTC control. These results highlight the significance and uniqueness of social benefits generated from controlling outbreaks of these insects, and provide a foundation for incorporating them into a full benefit-cost analysis used to help make more informed and efficient policy decisions. La presente etude a evalue les avantages collectifs de la lutte contre les invasions de deuxinsectes forestiers au Nouveau-Brunswick (NB) et en Saskatchewan (SK), a savoir la tordeuse des bourgeons de l’epinette (SBW) (Choristoneura fumiferana) et la livree des forets (FTC) (Malacosoma disstria). Au moyen de sondages postaux elabores selon la methode d’evaluation contingente avec choix dichotomiques, nous avons demandea des menages au NB et en SK d’indiquer leur consentement a payer pour lutter contre des invasions futures de SBW et de FTC. Une majorite de repondants (soit plus de 80p.100 dans chaque province) a indiqueetre en faveur de la lutte contre ces insectes. Dans les deuxprovinces, les repondants etaient en moyenne prets a payer davantage pour la lutte contre la SBW que pour la lutte contre la FTC. Les avantages collectifs globaux (evalues d’apres le surplus compensatoire) des programmes de lutte proposes au NB se sont soldes par des avantages collectifs annuels variant de 14,3 a 20,8millions de dollars (M$) dans le cas de la lutte contre la SBW et de 7,9 a 14,5M$ dans le cas de la lutte contre la FTC. En SK, les avantages collectifs nets ont ete comparables, variant de 22,2a32,4M$ dans le cas de la lutte contre la SBW, et de 11,7a22,0M$ dans le cas de la lutte contre la FTC. Ces resultats font ressortir l’importance et la valeur unique des avantages collectifs generes par la lutte contre les invasions de ces insectes et fournissent un argument pour les integrer dans une analyse avantages-couts afin de favoriser la prise de decisions strategiques eclairees et efficaces.

International trade is widely acknowledged as a conduit for movement of invasive species, but few studies have directly quantified the invasion risk confronting individual locations of interest. This study presents estimates of the likelihood of successful entry for alien forest insect species at more than 3,000 urban areas in the contiguous United States (US). To develop these location-specific estimates, we first utilized historical merchandise imports and insect incursions data to estimate an annual US rate of alien insect species establishment. Next, we used historical pest interception data to calculate the proportion of all insects arriving at US ports of entry that are associated with forest hosts. We then combined these results to estimate a nationwide establishment rate specifically for alien forest insects. Finally, we employed international and domestic commodity flow networks to allocate this nationwide rate to individual US urban areas. For 2010, we estimated the nationwide rate as 1.89 new alien forest insect species per year. While the establishment rates observed at most urban areas were low (

Landscape composition and physiognomy affect community structure and species distribution across space and time. The pine processionary moth (PPM) (Thaumetopoea pityocampa Den. & Schiff., Lepidoptera, Notodontidae) is a common pine defoliator throughout southern Europe and Mediterranean countries. We surveyed the spatiotemporal distribution of the PPM in a pine plantation forest in southwestern France and used the density of the winter nests as a proxy for population density. The study spanned 4 years (2005–2008) and showed a high temporal variability in nest density. We found a strong edge effect with nest densities at stand edges more than twice as large as within-stand densities. At the landscape scale, the spatial distribution of the moth exhibited a significant spatial autocorrelation in 3 out of 4 years of our study. The spatial scales of the autocorrelation ranged from ca. 2 km to more than 22 km. We found a positive correlation between spatial distributions corresponding to certain sampling years, but the relationship was not systematic. Landscape configuration appeared to be an important driver of the PPM spatial pattern. Bivariate Moran’s I correlograms showed that patch richness density as well as the percentage of local landscape covered by various land uses were correlated with population density. The study showed that accounting for landscape characteristics may be important in order to understand forest insect pest distribution, even in cases where the host species is abundant and homogeneously distributed throughout the study area, e.g., pure plantation forests.

Problems of influencing insect populations by changing the food quality. In forest entomology, as opposed to plant and livestock breeding it is not possible at the present stage to make use of changes in food quality as a routine technique for influencing insect populations. Although noticeable reactions of insects to changes in food quality have been known for a long time research on this matter has not yet reached a stage far beyond a first tentative screening. A careful elaboration of these questions is suggested to master the forthcoming problems like the cultures of clones of spruce trees or fertilizing of forest trees.

Destructive outbreaks of forest pests are classified as gradient, cyclical or eruptive. The first of two types of outbreaks (gradient, cyclical) are generated by stand and site conditions conducive to the reproduction and survival of the pest or stressfull for the host plant(s). In these cases, outbreak probability, or risk, can be assessed with unidimensional risk equations. Outbreaks of the third type, the eruptive pests, are more difficult to predict because the density of the pest plays a critical role in initiating outbreaks in particular stands. Risk assessment models for these pests require a two-dimensional structure that integrates stand, site and insect numbers. We discuss methods for developing risk assessment models for eruptive pests using, as an example, mountain pine beetle populations infesting lodgepole pine stands. Zusammenfassung Beurteilung des Risikos bei Forstinsekten-Kalamitaten Schadliche Massenvermehrungen von Forstinsekten werden eingeteilt in gradierende, zyklische und eruptive. Die ersten beiden Typen werden durch Bestandes- oder Lagebedingungen hervorgerufen, die fur die Reproduktion und das Uberleben des Schadlings gunstig oder fur die Wirtspflanze ungunstig sind. In solchen Fallen kann die Kalamitatswahrscheinlichkeit bzw. das Risiko mit eindimensionalen Gleichungen beurteilt werden. Kalamitaten des eruptiven Typs sind schwieriger zu prognostizieren, weil die Schadlingsdichte eine ausschlaggebende Rolle bei der Auslosung der Vermehrung in einzelnen Bestanden spielt. Modelle zur Risiko-Beurteilung erfordern hier eine zweidimensionale Struktur, in welcher Bestand, Lage und Insektendichte integriert sind. Es werden am Beispiel eines Befalls von Lodgepole-Kiefern durch den Mountain Pine Beetle Erorterungen uber die Entwicklung von Risikobeurteilungs-Modellen fur eruptive Schudlinge angestellt.