Search

Management responses to invasive forest insects are facilitated by the use of detection traps ideally baited with species-specific semiochemicals. Emerald ash borer, Agrilus planipennis Fairmaire, is currently invading North American forests, and since its detection in 2002, development of monitoring tools has been a primary research objective. We compared six trapping schemes for A. planipennis over 2 yr at sites in four U.S. states and one Canadian province that represented a range of background A. planipennis densities, canopy coverage, and ash basal area. We also developed a region-wide phenology model. Across all sites and both years, the 10th, 50th, and 90th percentile of adult flight occurred at 428, 587, and 837 accumulated degree-days, respectively, using a base temperature threshold of 10°C and a start date of 1 January. Most trapping schemes captured comparable numbers of beetles with the exception of purple prism traps (USDA APHIS PPQ), which captured significantly fewer adults. Trapping schemes varied in their trap catch across the gradient of ash basal area, although when considering trap catch as a binary response variable, trapping schemes were more likely to detect A. planipennis in areas with a higher ash component. Results could assist managers in optimizing trap selection, placement, and timing of deployment given local weather conditions, forest composition, and A. planipennis density. [ABSTRACT FROM AUTHOR]

Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an invasive pest causing extreme levels of mortality in ash (Fraxinus spp., Oleaceae) in the USA and Canada. Knowledge of buprestid chemical ecology is sparse, but the appearance of EAB in North America and its devastating ecological and economic impacts have afforded an opportunity to study its semiochemistry and biology in detail. We review the chemical ecology of EAB and the application of its sex pheromone, the female-produced (3 Z)-dodecen-12-olide ((3 Z)-lactone), and the green leaf volatile, (3Z)-hexenol, in operational surveys and experimental control strategies. Adding (3 Z)-lactone to green sticky prism traps with (3 Z)-hexenol on the south aspect of the tree canopy consistently increases trap captures and detection rates at low insect densities. This bait combination is more attractive than (3 Z)-hexenol alone, especially when traps are in a competitive deployment. Using a 'push–pull' strategy, some nonhost volatiles deployed in ash trees significantly lower trap capture and may be useful in the push component, with a girdled tree treated with systemic insecticide constituting the pull component. We review reliable branch sampling techniques to estimate incidence and density of EAB which positively correlate with trap capture. We recommend using these combined tools to detect, delimit, and monitor EAB. [ABSTRACT FROM AUTHOR]

We develop an acceptance sampling approach for surveillance of the emerald ash borer (EAB), a harmful forest pest, in Winnipeg, Canada. We compare sampling strategies computed with two different management objectives. The first objective maximizes the expected area with detected infestations and the second objective minimizes the expected number of undetected infested trees in sites that were not inspected or where inspection did not find an infestation. The choice of the management objective influences the survey strategy: achieving the first objective involves selecting sites with high infestation rates proximal to the infested area, whereas the second objective requires inspecting sites with both high infestation rates and high host densities. Adding uncertainty prescribes inspecting a larger area with lower sampling rates and extending the surveys to farther distances from the infested locations. If a decision maker wants to minimize the worst-case damage from failed detections, the optimal strategy is to survey more sites with high host densities at farther distances, where EAB arrivals could cause significant damage if not detected quickly. Accounting for the uncertainty addresses possible variation in infestation rates and helps develop a more diversified survey strategy. The approach is generalizable and can support survey programmes for new pest incursions. [ABSTRACT FROM AUTHOR]

The bronze birch borer, Agrilus anxius , is a North American buprestid pest of stressed or weakened birch trees (Betula spp.) and is considered a major threat to European birch species as a potentially adventive insect. Laboratory bioassays and field trapping experiments were conducted to elucidate potential visual and chemical cues used in host location in this species. Birch bark and foliar volatiles (Betula papyrifera Marsh) and a pheromone attractive to the congener, A. planipennis , (3 Z)-dodecen-12-olide ((3 Z)-lactone), were tested along with a girdled tree treatment, with purple sticky prism traps. Only the girdled tree treatment with purple traps elicited significant attraction by adult A. anxius. Various colours of sticky traps were tested with host volatiles attractive to A. planipennis ; results showed that unbaited green sticky traps were more attractive than other colours tested; none of the host volatiles tested increased trap capture with any traps. Examination of foliage and bark of B. papyrifera by GC/EAD, and GC/MS techniques has identified several EAD-active compounds with (3 Z)-hexenol and (5 S ,7 S)-conophthorin as the most EAD-active molecules. Neither compound, however, alone or combined, elicited significant trap capture on green sticky prism traps; these compounds may find importance as synergists once the pheromone for A. anxius is identified. [ABSTRACT FROM AUTHOR]

The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a highly destructive primary pest of ash (Fraxinus sp., Oleaceae) trees outside of its native range. Ash is an important component of many ecosystems and its loss would be detrimental to both the economy and the environment. The present study aimed to improve our understanding of the effectiveness of green sticky prism traps baited with host kairomone and insect pheromone lures for A. planipennis and to collect data for modelling the range of attraction of the pheromone (3Z)‐dodecen‐12‐olide [(3Z)‐lactone]. Traps were deployed over a single flight season in urban locations of Ontario, Canada, with low densities of EAB. Traps were placed in pairs of trees separated by not more than 25 m. All traps contained the host kairomone, (3Z)‐hexenol, with the remaining half in each pairing additionally baited with (3Z)‐lactone pheromone. Both lure types were highly effective in capturing EAB, with >90% detection rates overall. However, traps baited with the lactone pheromone and host volatile lures doubled trap captures of EAB over distances of at least 25 m from the nearest traps baited with only host volatiles. Although the baseline detection rate of traps containing (3Z)‐hexenol alone is not significantly reduced compared with traps containing (3Z)‐lactone, the overall trap effectiveness is significantly increased when (3Z)‐lactone is present. The implications for the use of (3Z)‐lactone at 3 mg per septum dose in an early warning trapping system are discussed. Trap layout methods and risk‐based analysis models can now be further refined by including these data about the attractive range of lures and their behaviour in different plot environments. [ABSTRACT FROM AUTHOR]

Detections of invasive species outbreaks are often followed by the removal of susceptible host organisms in order to slow the spread of the invading pest population. We propose the acceptance sampling approach for detection and optional removal of susceptible host trees to manage an outbreak of the emerald ash borer (EAB), a highly destructive forest pest, in Winnipeg, Canada. We compare the strategy with two common delimiting survey techniques that do not consider follow-up management actions such as host removal. Our results show that the management objective influences the survey strategy. The survey-only strategies maximized the capacity to detect new infestations and prioritized sites with high likelihood of being invaded. Comparatively, the surveys with subsequent host removal actions allocated most of the budget to sites where complete host removal would minimize the pest’s ability to spread to uninvaded locations. Uncertainty about the pest’s spread causes the host removal measures to cover a larger area in a uniform spatial pattern and extend to farther distances from already infested sites. If a decision maker is ambiguity-averse and strives to avoid the worst-case damages from the invasion, the optimal strategy is to survey more sites with high host densities and remove trees from sites at farther distances, where EAB arrivals may be uncertain, but could cause significant damage if not detected quickly. Accounting for the uncertainty about spread helps develop a more robust pest management strategy. The approach is generalizable and can support management programs for new pest incursions. [ABSTRACT FROM AUTHOR]

Recent research has demonstrated that the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), uses visual and chemical cues when locating potential mates and host trees. Here, we present the first evidence of the production of possible acoustic cues generated by adult males and females. We demonstrate for the first time that simultaneous wing opening and head 'pumping' in both males and females produce specific and distinct sounds. Acoustic recordings demonstrate that these sounds consist of a phrase comprising a 'click' generated by wing opening, followed by two separate chirps corresponding to the outward and subsequent inward movement of the head. Mean primary and secondary chirp durations were 0.332 ± 0.038 and 0.414 ± 0.046 s for males and 0.414 ± 0.046 and 0.389 ± 0.032 s for females, respectively. Overall mean phrase durations were 0.905 ± 0.114 s in males and 1.133 ± 0.133 s in females. Mean maximum phrase frequencies were 8 706.1 ± 141.1 and 7 885.0 ± 499.2 Hz in males and females, respectively. There were no significant differences in sound parameters between males and females. To determine whether these events were related to mating pair formation, we observed the occurrence of these events in adults paired with either another male or female and lone adults, and observed the number of mating pairs in copula formed during or shortly after sound production by either of the mating party. The mean number of sound‐generating events per min was significantly greater in males paired with females (0.75 ± 0.15) and/or other males (0.55 ± 0.23) vs. unpaired males (0.14 ± 0.06). Conversely, the mean number of sound‐producing events for lone females (1.4 ± 0.2) was significantly greater than for females paired with either males (0.49 ± 0.18) or other females (0.38 ± 0.10). No mating pairs in copula were formed during any of our observations. Scanning electron microscopy images showed the presence of possible pars stridens and plectrum structures on the ventral surfaces of the gula and pronotum in both males and females. Furthermore, we observed that the proportion of males and females exhibiting these specific behaviors were significantly greater under both halogen and incandescent light than under darkness, signifying the importance of light source or type on the production of acoustic signals. Although we did not find evidence of these behaviors being related to the courtship sequence, our results indicate the presence of a previously undescribed sound‐generation behavior in A. planipennis that is significantly influenced by light conditions. A trap that utilizes attractive plant and pheromone volatiles to detect emerald ash borer (EAB) (Coleoptera: Buprestidae) adults is the principal method for monitoring EAB populations. This trap exploits visual and chemical cues used by EAB adults to locate host trees and one another. An additional, yet undescribed, sensory modality in EAB is the role of acoustic cues produced by adults. We describe for the first time the existence of quantifiable and detectable acoustic sounds generated by EAB adults. [ABSTRACT FROM AUTHOR]

Emerald ash borer, Agrilus planipennis Fairmaire (EAB) (Coleoptera: Buprestidae), has caused devastating levels of mortality to ash trees (Fraxinus Linnaeus, Oleaceae) in North America. Early infestations of this insect are extremely difficult to detect due to cryptic larval feeding and lack of obvious signs or symptoms of initial attack. Considerable research has been conducted to develop tools and techniques aimed towards providing early detection and delimitation of populations of this invasive species. Sampling tools and techniques include: (1) relating visual signs and symptoms to the presence of EAB infestations; (2) use of girdled trap-trees to increase captures of adults and subsequent larval densities; (3) sub-sampling protocols to detect larvae under the bark based on their within-tree distribution; (4) artificial traps baited with pheromones and/or host volatiles attractive to adult EAB; (5) biosurvellience using buprestid-hunting wasps; and (6) remote sensing techniques. Additional research modelling patterns of infestation at the landscape scale indicate very clumped or aggregated distributions, greatly increasing the difficulty of early detection across large spatial scales. Further research is still required to increase the efficacy and efficiency of early detection tools and techniques, including cost/benefit analysis of the various sampling options, increased understanding of patterns of initial infestation across the landscape, development of sampling programs for both detection and delimitation, and development of sequential sampling programs to estimate EAB density. This information will enable foresters to make informed decisions regarding management strategies against this devastating pest. [ABSTRACT FROM PUBLISHER]

Copyright of Canadian Entomologist is the property of Cambridge University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Early detection of emerald ash borer (EAB) (Agrilus planipennis Fairmaire; Coleoptera: Buprestidae) infestation is problematic, with visual indicators not appearing until late during an infestation, and detection methods often requiring substantial trade-offs between information yielded and cost. Decision makers must determine which detection methods provide sufficiently valuable information that matches their objectives and adhere to budget constraints. Notably, decision makers from different organisations often have different objectives; hence their perceptions of costs and benefits of these choices can vary. Economic thought and analysis can provide useful insights for decision makers concerned with understanding and balancing costs and benefits associated with detection strategies. Here we provide a brief review of economic studies of EAB and present a conceptual framework on the detection strategy problem drawing on “information economics”. [ABSTRACT FROM PUBLISHER]

Woodborers in the Agrilus genus ( Coleoptera: Buprestidae) pose high invasiveness risk as indicated by the recent invasion and continental spread of emerald ash borer, and the associated threat to ash resources in North America. In that context, development of detection tools for potentially invasive Agrilus spp. is a research priority. Experiments carried out in 2013 in Slovakian beech and poplar forests evaluated the attraction of multiple Agrilus species to green and purple sticky prism traps baited with various lures [blank, cubeb oil, ( Z)-3-hexenol]. The two most abundant species were Agrilus viridis L. in beech ( Fagus spp.) forest (146 adults, >95% of which were females) and Agrilus convexicollis Redtenbacher in poplar ( Populus spp.) forest (158 adults, two-thirds of them males). The two species exhibited opposite responses to color: purple traps attracted 2-3× more adult A. viridis than green traps, whereas most (>95%) specimens of A. convexicollis were captured on green traps. Volatile baits did not influence captures of adults for either species. The introduction and establishment of A. viridis in North America is of particular concern owing to its feeding niche (primary pest that can attack healthy trees), large body size, and high level of polyphagy (>10 genera of host trees). Additional experiments conducted in beech forests in 2014 found purple prism traps more attractive to female A. viridis than green prism traps, especially those baited with cubeb oil. No analysis was conducted for males because of their low abundance. Female A. viridis flew earlier in 2013 than in 2014, but neither their body size nor fecundity varied between years. In both years, large females had more eggs in their abdomen than small females, and the number of eggs steadily declined over time, which suggests that female A. viridis are reproductively mature at emergence. [ABSTRACT FROM AUTHOR]

Female emerald ash borers, Agrilus planipennis (Coleoptera: Buprestidae), emit a macrocyclic lactone, ( Z)-3-dodecen-12-olide, that increases field trap captures on large-panel prism traps when co-emitted with the green leaf volatile ( Z)-3-hexenol. We assessed attraction to these compounds by using visual decoy-baited branch traps, which attract males by mimicking a living female resting upon a leaf. Pairs of branch traps, with and without visual decoy beetles, were placed on green ash, Fraxinus pennsylvanica, trees, which were assigned different odor treatments: 1) no odor, 2) ( Z)-3-hexenol alone, and 3) ( Z)-3-hexenol-plus-lactone. Male captures were positively affected by the presence of decoys and the emission of either ( Z)-3-hexenol or ( Z)-3-hexenol plus lactone. The decoy-baited traps with the combination of ( Z)-3-hexenol plus lactone caught more males than any other treatment. Greater male captures were associated with continuing captures later in the season, suggesting that decoy and odor attractants remain attractive throughout the flight period. Female captures were not affected by the visual decoys, but odors did influence captures, with the ( Z)-3-hexenol plus lactone treatment catching the greatest number of females. The rare female trap captures were negatively correlated with the more common male captures on the odorless and ( Z)-3-hexenol-baited traps, but were not correlated with male captures when the lactone was added. Thus, in the absence of the lactone, the visual signal of other conspecifics can inhibit female attraction. However, the pheromone attracts both sexes independently of the visual signal on the trap. [ABSTRACT FROM AUTHOR]

Agrilus planipennis (Coleoptera: Buprestidae), is causing extensive mortality of ash (Fraxinus Linnaeus; Oleaceae) in North America. Once detected in an area, resource managers require methods to obtain estimates that could improve management decisions. We studied the within-crown and within-branch distribution and abundance of A. planipennis feeding galleries by sampling 3-m-long branches from asymptomatic urban ash trees and subdividing each branch into 12 sections of 25 cm each. We found galleries in all 12 sections of some, but not all, branches. Section was a significant source of variation in A. planipennis gallery density/m² of branch surface area. A comparison of predictive power and efficiency of estimates for samples of increasing length, and for samples of the same length but consisting of different combinations of sections, revealed that those based on the two basal 25-cm sections of a branch from the lower-crown or mid-crown of an asymptomatic tree were less accurate and precise than those based on more sections, but were the most cost effective. Whittling more sections per branch, irrespective of the combinations of branch sections per length, improved predictive power but reduced cost effectiveness. We also observed that crown level was not important, and aspect was only marginally so, when estimating gallery abundance per sampled branch. [ABSTRACT FROM AUTHOR]

Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae) is a North American parasitoid now using Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) as a novel host, and may prove useful in biocontrol. Unfortunately, information is lacking regarding mating and the presence of pheromones, which may be important when attempting to exploit this parasitoid within a management context. Herein we used olfactometer assays and behavioural observations to determine the courtship and mating sequences of P. sulcata. A significantly higher proportion of males oriented towards females over the control arm containing filtered air in an olfactometer regardless of the age classes of females or males examined. We also observed four pre-copulatory behaviours that were consistent in all mating pairs. Our results indicate that courtship may be mediated by male perception of female-produced pheromones. Understanding the courtship sequence may be useful in rearing laboratory populations, while the putative pheromones may be useful in detection and retention of P. sulcata populations. [ABSTRACT FROM PUBLISHER]

Aim We address the problem of geographically allocating scarce survey resources to detect pests in their pathways of introduction given information about their likelihood of movement between origins and destinations. We introduce a model for selecting destination sites for survey that departs from the aim of reducing propagule pressure (PP) in pest destinations and instead aims to increase monitoring of pest origins. The model is a maximum expected coverage problem (MECP), which maximizes the expected number of origins that are covered by the survey system, where an origin is covered if at least one of its transmission pathways connects to a surveyed destination. For comparison, we present two models that aim to reduce PP in destination sites. One model maximizes the expected number of transmission pathways that are covered by survey locations and the other maximizes the expected number of survey locations that have one or more pest introductions. Location United States, Canada. Methods We demonstrate the models by analysing the human-mediated spread of the emerald ash borer ( Agrilus planipennis Fairmaire), a major pest of ash trees in North America, by visitors to campgrounds in central Canada and the US Midwest. The models incorporate estimates of spread rates from a network of campers travelling from approximately 6500 invaded domains to 266 uninvaded campgrounds in three Canadian provinces (Ontario, Quebec and Manitoba) and three US states (Michigan, Minnesota and Wisconsin). Results The MECP and PP-based model solutions agreed for large surveillance budgets but exhibited differences when the budgets were small. These results stem from differences between the coverage-based objective in MECP and the PP-based metrics in the PP models. Main conclusions Our comparison of MECP and PP-based models reveals the trade-offs between objectives. Overall, the MECP is generic and can be adapted to survey species that are spread via other human-mediated vectors. [ABSTRACT FROM AUTHOR]

Monochamol (2-undecyloxy-1-ethanol) is a male-produced aggregation pheromone for several Monochamus Dejean (Coleoptera: Cerambycidae) species. We conducted trapping experiments in Canada, Poland, and China to test whether monochamol was attractive to additional Monochamus species and if attraction was synergised by plant volatiles and bark beetle (Coleoptera: Curculionidae) pheromones. We provide the first evidence of attraction for M. urussovii (Fischer) and M. saltuarius (Gebler) to monochamol or monochamol+kairomones. The highest numbers of M. urussovii were captured in traps baited with monochamol+plant volatiles (Manuka oil, ethanol and (95/5±) α−pinene). Captures of M. saltuarius were highest in traps baited with monochamol, with the addition of cubeb oil tending to reduce captures. The highest numbers of M. scutellatus (Say) were captured in traps baited with monochamol+kairomones. A similar pattern in trap captures was found for M. notatus (Drury), M. marmorator Kirby, M. carolinensis (Olivier), and M. mutator LeConte. Detection rates, that is, proportion of traps capturing at least one specimen, was highest for traps baited with monochamol plus kairomones, particularly for less-common species. These results support the emerging hypothesis that pheromone compounds can attract related cerambycid species with cumulative evidence for attraction to monochamol for 12 species of Monochamus worldwide. [ABSTRACT FROM PUBLISHER]

First detected in North America in 2002, the emerald ash borer (EAB) (Agrilus planipennis Fairmaire; Coleoptera: Buprestidae), an invasive phloem-feeding beetle from Asia, has killed tens of millions of ash (Fraxinus Linnaeus; Oleaceae) trees. Although few parasitoids attack EAB in North America, three parasitoid species were found attacking EAB in China: the egg parasitoid Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) and two larval parasitoids Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae). In 2007, classical biological control of EAB began in the United States of America after release of these three species was approved. In 2013, release of the larval parasitoids was approved in Canada. Research continues at study sites in Michigan, United States of America where the establishment, prevalence, and spread of O. agrili and T. planipennisi have been monitored since 2008. However, establishment of S. agrili remains unconfirmed in northern areas, and its release is now restricted to regions below the 40th parallel. In 2015, approval for release of Spathius galinae Belokobylskij (Hymenoptera: Braconidae), an EAB larval parasitoid from the Russian Far East, may be granted in the United States of America. Researchers are guardedly optimistic that a complex of introduced and native natural enemies will regulate EAB densities below a tolerance threshold for survival of ash species or genotypes in forested ecosystems. [ABSTRACT FROM PUBLISHER]

The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a destructive invasive pest that threatens North American ash (Fraxinus (Oleaceae)) and inflicts substantial aesthetic, ecological, and economic damage in urban forests and rural woodlands. Understanding adult EAB dispersal and spread of infestations is critical to effectively manage and mitigate its potential impact in North America and elsewhere. Challenges of quantifying short-distance and long-distance movement of adult EAB in the field remain exceptionally difficult. Here we review our current understanding of EAB spread. Research to date suggests natural spread of EAB populations is variable and influenced by local environmental conditions, but limited to only a few km per year. In contrast, long-distance spread resulting from anthropogenic movement of infested ash material, such as nursery trees or firewood, can greatly increase local and regional rate of spread through the formation of satellite populations. Key areas in need of future research are highlighted. [ABSTRACT FROM PUBLISHER]

Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a non-native, wood-boring beetle that has caused widespread mortality of ash (Fraxinus Linnaeus (Oleaceae)) in eastern North America. During 2004–2007, we determined whether forest community composition and structure of black (F. nigra Marshall), green (F. pennsylvanica Marshall), and white (F. americana Linnaeus) ash stands influenced their susceptibility to EAB invasion in southeast Michigan, United States of America. There was no relationship between EAB-induced ash decline or percentage mortality and any measure of community composition (tree species diversity, stand/ash density, total basal area, or relative dominance of ash). There was also no relationship between measures of EAB impact (density of EAB signs, ash decline rating, percentage ash mortality, or percentage infested ash) and forest attributes (ash/total stand density, basal area, ash importance, or stand diversity). Decline and mortality of black ash advanced more rapidly than that of white and green ash. Percentage mortality of ash increased from 51% to 93% during 2004–2007. Distance from the epicentre of the invasion was negatively correlated with ash mortality, but this relationship dissipated over time. Stand composition data suggests that ash will be replaced by Quercus Linnaeus (Fagaceae), Acer Linnaeus (Sapindaceae), and Tilia Linnaeus (Malvaceae); such vegetation changes will irreversibly alter the structure and function of these forests. [ABSTRACT FROM PUBLISHER]

Practical and effective strategies to manage emerald ash borer (EAB) (Agrilus planipennis Fairmaire; Coleoptera: Buprestidae) are increasingly important given economic and ecological impacts of this invader. While EAB detection remains challenging, tactics are available to protect individual ash (Fraxinus Linnaeus; Oleaceae) trees and slow EAB population growth, thereby delaying ash mortality. Simulations with a coupled map lattice model, parameterised with data from numerous field studies, showed treating trees with a highly effective systemic insecticide (TREE-äge™; emamectin benzoate), would be more effective in slowing EAB population growth than girdling trees to attract ovipositing females then destroying trees before larvae develop, while harvesting ash to reduce available phloem would have the least effect. From 2008 to 2012, cooperators participated in a pilot project to implement an integrated strategy for an EAB infestation in Upper Michigan, United States of America. Ash was inventoried and EAB density monitored using girdled ash detection trees supplemented with baited artificial traps across the >750 km2 project area. While only a tiny fraction of ash trees in the project area were girdled (444–855 trees annually) or injected with TREE-äge™ (<360 roadside trees annually), and treatment distribution was restricted, both treatments slowed EAB population growth. Coupling TREE-äge™ injections with other tactics will likely yield additive or synergistic outcomes. [ABSTRACT FROM PUBLISHER]

As of summer 2014, the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has become established in 24 states in the United States of America and has killed tens of millions of ash trees since its introduction into Michigan in the 1990s. Considerable research has been conducted on many aspects of EAB life history, natural history, ecology, and management strategies in an attempt to contain this devastating pest. In this article, we review the life history, mating behaviours, and host plant selection by EAB in North America as well as host resistance to EAB attack. [ABSTRACT FROM PUBLISHER]

Emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an Asian species that was introduced into North America in the mid-1990s. The beetle has the potential to devastate populations of Fraxinus Linnaeus (Oleaceae) species. Several species of Hymenoptera parasitoids have made the transition from North American Agrilus Curtis hosts to A. planipennis, and some (e.g., Atanycolus Förster (Hymenoptera: Braconidae) species) have caused substantial mortality. Invertebrate predators of A. planipennis have been poorly investigated. Predation by woodpeckers (Aves: Picidae) has had the greatest impact on A. planipennis populations. Native entomopathogens have also been observed in populations of A. planipennis and are being explored as potential biological control agents. Agrilus planipennis is a freeze-intolerant species and as such perishes when its tissues freeze. However, the beetle can achieve a mean supercooling point of −30 °C by the production of cryoprotectants, especially glycerol. This low supercooling point in combination with temperatures higher than ambient in its overwintering microhabitat means that it can survive in most of its invaded range. As its distribution expands northward its cold hardiness may be challenged. North American species of Fraxinus possess some resistance to A. planipennis via defensive mechanisms, but these are quickly overcome by expanding larval populations. Intraspecific competition (via cannibalism and starvation) impacts larval survival. [ABSTRACT FROM PUBLISHER]

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a devastating insect pest in its introduced range. A trapping system that increases trap catches or detection rates in low-density populations would be beneficial for survey programs. Five trapping experiments were conducted to investigate factors influencing capture rates of male beetles on dark green traps baited with the A. planipennis pheromone, (3Z)-dodecen-12-olide ((3Z)-lactone), plus the green leaf volatile, (3Z)-hexenol. Low doses (0.001-1.0 mg) of (3Z)-lactone + (3Z)-hexenol did not consistently increase captures of male A. planipennis. In other experiments, mean captures of males were significantly higher on traps baited with a moderate dose (3.0 mg/septum) of (3Z)-lactone + (3Z)-hexenol, compared with lower doses (0.001, 0.1, and 1.0 mg) or (3Z)-hexenol alone. Next, we demonstrated that addition of (3Z)-lactone to traps baited with (3Z)-hexenol resulted in significantly greater increases in male captures when pairs of traps were placed on the same tree, than when traps were placed on adjacent trees. Moreover, significantly more A. planipennis were captured on pheromone-baited traps placed in the southern versus northern aspect of the crown. These results highlight the importance of experimental set-up for elucidating lure treatment effects and also suggests the (3Z)-lactone may be more active at close range. Our findings increase our understanding of the pheromone ecology of this species and lend support toward the use of dark green traps baited with 3.0 mg (3Z)-lactone + (3Z)-hexenol deployed in the south aspect of the canopy for detection programs for this insect. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious invasive pest of North American ash ( Fraxinus spp.) that has caused devastating mortality since it was first identified in North America in 2002. In 2012, we conducted field trapping assays that tested the efficacy of purple prism and fluon-coated green multifunnel (Lindgren funnel) traps. Traps were baited with combinations of several lures that were previously shown to be attractive to A. planipennis: manuka oil-a sesquiterpene-rich oil, (3Z)-hexenol-a green leaf volatile, or (3Z)-dodecen-12-olide [= (3Z)-lactone], a sex pheromone. Eighty-nine blocks (trap lines) were tested throughout nine states along the outer edges of the currently known A. planipennis infestation in North America. Trap catch was highest on fluon-coated green multifunnel traps, and trap detections at sites with low A. planipennis population density ranged from 72 to 76% for all trap and lure types tested. (3Z)-hexenol and (3Z)-lactone baited traps functioned as well as (3Z)-hexenol and manuka oil-baited traps. Independent of the lure used, detection rates on green fluon-coated multifunnel traps were comparable with glued purple prism traps in areas with low A. planipennis population densities. [ABSTRACT FROM AUTHOR]

Emerald ash borer, Agrilus planipennis Fairmaire ( Coleoptera: Buprestidae), is a major pest of ash trees, Fraxinus spp. (Oleaceae), in North America. This study investigated the timing of reproductive development in female beetles and the influence of female reproductive maturity on attraction to host volatiles. Based on dissections of females of increasing age, females with access to males for mating, and thus presumed mated, developed mature eggs only after 18-24 days. In contrast, female beetles reared without access to males, and thus unmated, did not develop mature eggs at any age. Chemical analysis of cuticular hydrocarbons detected the contact sex pheromone, 9-methyl-pentacosane, in cohorts of females which were 8-9 days old and older, supporting previous research that this compound signals sexual maturity to males. Results from field-trapping bioassays demonstrated that stage of female reproductive maturity influenced their attraction to host volatiles: females caught on traps baited with foliar volatiles contained eggs and ovarioles that were significantly less developed than those on traps baited with bark sesquiterpenes. However, our results revealed that females with immature stages of ovarioles and undeveloped eggs, such as those observed in unmated females, were rarely ever caught on traps baited with either of the host volatile lures. Further research on host compounds attractive to immature females is critical for early detection and possible control of A. planipennis populations during the extended pre-oviposition period. [ABSTRACT FROM AUTHOR]

The invasive emerald ash borer, Agrilus planipennis Fairmaire ( Coleoptera: Buprestidae), is a major pest of ash trees, Fraxinus spp., in its introduced range in North America. Field studies were conducted to quantify the efficacy of traps baited with kairomone and pheromone lures for early detection of A. planipennis infestation. A trapping experiment demonstrated that green traps baited with the kairomone (3 Z)-hexenol detected at least one adult A. planipennis in 55.3% of plots with 'nil to low'-density infestations and in 100% of plots with 'moderate to high'-density A. planipennis infestations. Mean trap captures increased significantly with increasing infestation density. In terms of the optimal number of traps per plot, when one (3 Z)-hexenol-baited trap was placed per plot, the trap detected populations in 62% of the plots with 'low to moderate'-density infestations through branch sampling. Detectability was increased to 82% when two traps were placed per plot. Finally, addition of female-produced (3 Z)-lactone pheromone to traps significantly increased detection rates at both the trap and plot level, as compared with traps baited with the host volatile, (3 Z)-hexenol, alone (88 vs. 60%, respectively). Our results are the first to demonstrate the efficacy of baited green sticky traps for detecting low-density A. planipennis infestations, particularly when the (3 Z)-lactone pheromone is used. This combination is therefore recommended for development of early-detection protocols against A. planipennis. [ABSTRACT FROM AUTHOR]

Attraction of emerald ash borer, Agrilus planipennis Fairmaire, to a volatile pheromone was demonstrated in three field experiments using baited green sticky traps. A dose-response curve was generated for male A. planipennis to increasing release rates of (3Z)-dodecen-12-olide ( (3Z)-lactone) in combination with the green leaf volatile, (3Z)-hexenol. Only the lowest release rate (<2.50 µg/d) of (3Z)-lactone significantly increased captures of male A. planipennis, as compared with traps baited with (3Z)-hexenol alone. Effect of trap height, (3Z)-lactone, and (3Z)-hexenol and their interactions on the trap capture of A. planipennis was determined in a factorial experiment. Number of males per trap was significantly and positively affected by (3Z)-lactone, (3Z)-hexenol, and trap height whereas number of females per trap was affected by trap height only; none of the interactions were significant. As predicted, the greatest mean catch of males was in traps baited with (3Z)-lactone and (3Z)-hexenol placed high in the canopy. Electroantennogram tests on the bark volatile, 7-episesquithujene, demonstrated the ability of male and female A. planipennis antennae to detect and respond to this compound, particularly the (+)-7-epi-sesquithujene isomer. Results from an olfactometer bioassay and field testing did not demonstrate attraction of either males or females to (+)-7-epi-sesquithujene. These data increase our understanding of the pheromone ecology of the invasive emerald ash borer, provide further confirmation of the behavioral activity of the female-produced lactone pheromone, and should increase the ability to detect A. planipennis infestations where they are present. [ABSTRACT FROM AUTHOR]

Analysis by gas chromatography/mass spectrometry (GC/MS) of volatiles from virgin female emerald ash borer, Agrilus planipennis Fairmaire confirmed the emission of (3Z)-lactone [(3Z)-dodecen-12-olide] but not its geometric isomer, (3E)-lactone [(3E)-dodecen-12-olide]. Gas chromatographic/electroantennographic (GC/EAD) analysis of synthetic (3Z)-lactone, which contained 10% (3E)-lactone, showed a strong response of male and female antennae to both isomers. EAG analysis with 0.01- to 100-/µg dosages showed a positive dose response, with females giving significantly higher responses than males. In field experiments with sticky purple prism traps, neither lactone isomer affected catches when combined with ash foliar or cortical volatiles (green leaf volatiles or Phoebe oil, respectively). However, on green prism traps, the (3Z)-lactone significantly increased capture of male A. planipennis when traps were deployed in the canopy. Captures of males on traps with both (3E)-lactone and (3Z)-hexenol or with (3Z)-lactone and (3Z)-hexenol were increased by 45-100%, respectively, compared with traps baited with just (3Z)-hexenol. In olfactometer bioassays, males were significantly attracted to (3E)-lactone, but not the (3Z)-lactone or a 60:40 (3E):(3Z) blend. The combination of either (3E)- or (3Z)-lactone with Phoebe oil was not significantly attractive to males. Males were highly attracted to (3Z)-hexenol and the (3Z)-lactone + (3Z)-hexenol combination, providing support for the field trapping results. These data are the first to demonstrate increased attraction with a combination of a pheromone and a green leaf volatile in a Buprestid species. [ABSTRACT FROM AUTHOR]

The emerald ash borer, Agrilus planipennis Fairmaire, is an exotic invasive insect causing extensive mortality to ash trees, Fraxinus spp., in Canada and the United States. Detection of incipient populations of this pest is difficult because of its cryptic life stages and a multiyear time lag between initial attack and the appearance of signs or symptoms of infestation. We sampled branches from open-grown urban ash trees to develop a sample unit suitable for detecting low density A. planipennis infestation before any signs or symptoms are evident. The sample unit that maximized detection rates consisted of one 50-cm-long piece from the base of a branch ⩾6 cm diameter in the midcrown. the optimal sample size was two such branches per tree. This sampling method detected ≈75% of asymptomatic trees known to be infested by using more intensive sampling and ≈3 times more trees than sampling one-fourth of the circumference of the trunk at breast height. The method is less conspicuous and esthetically damaging to a tree than the removal of bark from the main stem or the use of trap trees, and could be incorporated into routine sanitation or maintenance of city-owned trees to identify and delineate infested areas. This research indicates that branch sampling greatly reduces false negatives associated with visual surveys and window sampling at breast height. Detection of A. planipennis-infested asymptomatic trees through branch sampling in urban centers would provide landowners and urban foresters with more time to develop and implement management tactics. [ABSTRACT FROM AUTHOR]

The physiological indices of Chinese cabbage(Brassica chinensis L.) grown under different intercropping systems used for this study included total soluble protein content, soluble sugar content, reducing sugar content, nitrate content, and pigment concentration. The objective of the present study is to discover the physiological level changes in Chinese cabbage in intercropping systems. The intercropping systems studied involved Chinese cabbage- garlic (Allium sativum L.) (CG), and Chinese cabbage-lettuce (Lactuca sativa L.) (CL). Chinese cabbage monoculture served as control (CK). Overall, higher mean soluble protein content and nitrate content were found in Chinese cabbage grown in the intercropping systems than those in CK. Significantly higher chlorophyll a content was found in cabbages from CL than CK during the latter half of the growing season. No significant difference in soluble sugar concentrations was found in CG and CL, as compared with CK. Reducing sugar content varied over the growing period of the Chinese cabbage in CG and CL. These results suggest that Chinese cabbage intercropped with noncrucifer plants increase the plant nutrient content. [ABSTRACT FROM AUTHOR]

Spruce budworm ( Choristoneura fumiferana (Clemens)) is one of the most serious forest insect pests in North America. Laboratory bioassays were performed to determine the lethal doses and lethal time of pyrethrins (a botanical insecticide) on 4th instar larvae of spruce budworm using larval dip assay. Results show that the LT values (time of 50% larval mortality) for spruce budworm at the pyrethrins concentrations of 12.5, 25, 50, 100, and 200 μg·L were 94.78, 45.54, 20.36, 14.39 and 11.37 h, respectively. The percentage of cumulative mortality at the pyrethrins concentrations of 12.5, 25, 50, 100, 200 μg·L was approximately 50%, 67%, 93%, 100% and 100% within 120 h, respectively. The LC value (concentration of 50% larval mortality) for the 4 instar larvae was 16.1μg·L. Thus, larval mortality of spruce budworm increased in a concentration-dependent manner, and lethal time decreased with increasing pyrethin concentrations. These findings suggest that pyrethrins have a potential in controlling spruce budworm populations. [ABSTRACT FROM AUTHOR]

The elm spanworm, Ennomos subsignaria (Hübner), occurs throughout Canada and the eastern United States and can be a destructive forest pest on a wide range of deciduous trees. Gas chromatography/mass spectrometry (GC/MS) and coupled gas chromatographic–electroantennographic detection (GC/EAD) analysis of pheromone gland extracts, in combination with chemical synthesis and field trapping studies have identified (2 S, 3 R)-2-(( Z)-oct-2′-enyl)-3-nonyl oxirane (hereafter Z6-9 S, 10 R-epoxy-19:H) as the female-produced sex pheromone. Significantly more male moths were captured between 1–100 μg loadings of this compound on red rubber septa in sticky traps compared to blank (unbaited) traps; catches then declined at higher dosages (500–1000 μg). The other isomeric enantiomer, (2 R, 3 S)-2-[( Z)-oct-2′-enyl]-3-nonyl oxirane ( Z6-9 R, 10 S-epoxy-19:H), at a 10-μg dosage did not elicit trap capture. The likely precursor to the active epoxide, ( Z, Z)-6, 9-nonadecadiene (( Z, Z)-6, 9-19:H), identified in virgin female sex pheromone glands, did not elicit trap capture either, and inhibited trap capture when combined with the active epoxide. Racemic 2-((Z)-oct-2′-enyl)-3-nonyl oxirane showed no significant difference in trap capture compared with Z6-9 S, 10 R-epoxy-19:H, indicating that the opposite enantiomer was not antagonistic. The addition of the EAD-active diene epoxide enantiomers (2 S, 3 R)-2-[( Z, Z)-octa-2′, 5′-dienyl]-3-nonyl oxirane or (2 R, 3 S)-2-[( Z, Z)-octa-2′, 5′-dienyl]-3-nonyl oxirane in admixture with Z6-9 S, 10 R-epoxy-19:H (at 10% of the latter) did not enhance or decrease trap capture compared to Z6-9 S, 10 R-epoxy-19:H oxirane alone, so they are not likely pheromone components. This pheromone, impregnated in rubber septa at less than 100-μg dosage, can now be used as a trap bait to develop detection and monitoring strategies for this insect. [ABSTRACT FROM AUTHOR]

1. Field surveys and a manipulative experiment were conducted to examine the hypotheses that intra-tree heterogeneity in natural enemy activity, foliar quality (independent of phenology), or phenology influence the intra-tree distribution and performance of Ennomos subsignaria on mature sycamore maple, Acer pseudoplatanus. 2. Ennomos subsignaria intra-tree distribution was distinctly clumped. Egg mass density was 85% higher on the lower bole than in the crown. Most early instars were found on lower crown proximal branches while most late instars and pupae were found on lower crown distal branches. This resulted in high levels of defoliation in the lower crown, especially on proximal branches. 3. No parasitoids were reared from eggs or late-instar larvae and only one pupa was parasitised, suggesting that preference for the bole and lower crown was not a response to parasitism. Similarly, E. subsignaria performance was not influenced by variable foliage quality (independent of phenology) within the crown. However, sycamore maple phenology had a large influence on E. subsignaria survival. More than 90% of newly emerged larvae survived to the adult stage when they fed on foliage with three pairs of leaves expanded per bud, whereas survival on younger foliage was reduced by >45%. 4. The peak period of E. subsignaria egg hatch was approximately 2 weeks after the peak period of sycamore maple budburst, which occurred acropetally. Egg hatch was closely synchronised with the availability of most suitable leaves for insect development on proximal branches of the lower crown, the location where most larvae initiated feeding. 5. The results support the phenology hypothesis and suggest that intra-tree variation in oviposition site and host phenological development influence the intra-tree distribution and performance of this generalist herbivore. [ABSTRACT FROM AUTHOR]

Trees in an urban forest are highly valued because they have esthetic appeal, provide shade, and improve air quality. During the past 5 yr (2002-2006) in St. John's, Newfoundland and Labrador, Canada, the elm spanworm, Ennomos subsignaria (Hübner) (Lepidoptera: Geometridae), has reached outbreak densities. Each year, hundreds of trees have been completely defoliated, and many more trees have been partially defoliated. Adding to this problem, the larvae, their silk strands, and their frass are a considerable nuisance to property owners in areas of high larval densities. In this study, we evaluated the efficacy of three doses of bole-implanted acephate (AceCap 97) for reducing densities and associated defoliation of E. subsignaria on sycamore maple, Acer pseudoplatanus L. (Aceraceae). During the treatment year (2005), all three doses significantly reduced E. subsignaria larval and pupal density; full or two-thirds doses significantly reduced defoliation compared with control trees. During the posttreatment year (2006), bole-implanted acephate did not affect E. subsignaria egg mass density, survival (= adult emergence), or defoliation. Bole-implanted acephate is an effective and practical way of suppressing E. subsignaria densities and herbivory in an urban forest where the protection of high-value trees and the reduction of environmental contamination are of utmost importance. [ABSTRACT FROM AUTHOR]

Despite extensive empirical research and previous reviews, no clear patterns regarding the effects of habitat loss and fragmentation on predator-prey interactions have emerged. We suggest that this is because empirical researchers do not design their studies to test specific hypotheses arising from the theoretical literature. In fact, theoretical work is almost completely ignored by empirical researchers, perhaps because it may be inaccessible to them. The purpose of this paper is to review theoretical work on the effects of habitat loss and fragmentation on predator-prey interactions. We provide a summary of clear, testable theoretical predictions for empirical researchers. To test one or more of these predictions, an empiricist will need certain information on the predator and prey species of interest. This includes: (I) whether the predator is a specialist on one prey species or feeds on many kinds of prey (omnivore and generalist); (2) whether the predator is restricted to the same habitat type as the focal prey (specialist), can use a variety of habitats but has higher survival in the prey habitat (omnivore), or lives primarily outside of the focal prey's habitat (generalist); (3) whether prey-only patches have lower prey extinction rates than predator-prey patches; and (4) whether the prey emigrate at higher rates from predator-prey patches than from prey-only patches. Empiricists also need to be clear on whether they are testing a prediction about habitat loss or habitat fragmentation and need to conduct empirical studies at spatial scales appropriate for testing the theoretical prediction(s). We suggest that appropriate use of the theoretical predictions in future empirical research will resolve the apparent inconsistencies in the empirical literature on this topic. [ABSTRACT FROM AUTHOR]

Increasing intensity of land use by humans has led to loss of natural habitats, resulting in isolation of remaining habitat fragments. Using a pine-bark beetle ecosystem as a model, we tested the hypothesis that the ratio of abundance of predators to prey should decrease with increasing habitat loss at the landscape scale. We selected ten red pine ( Pinus resinosa) sites, representing extremes of available habitat within a 2 km radius surrounding each stand. The bark beetle, Ips pini, and its coleopteran predators were sampled using baited multiple funnel traps. Effects of stand isolation were considerable; ratios of predators to prey (mean number of predators/number of prey±SE) were significantly reduced in isolated stands (0.38±0.09) as compared to those with large amounts of surrounding conifer habitat (1.63±0.41). The decline in ratio occurred both because there was: a) a lower abundance of predators (ca 0.5–0.8×) captured in isolated stands; and b) a significantly higher number of prey (ca 2.2×) captured in isolated stands. Isolation or loss of habitat, therefore, differentially affected the two trophic levels, supporting theoretical predictions. Reductions in predator abundance and, presumably, enemy-caused mortality may lead to changes in the population dynamics of their prey species, possibly leading to increased outbreaks as habitat becomes increasingly isolated. [ABSTRACT FROM AUTHOR]

The article introduces various papers on the emerald ash borer (EAB) published within the issue, including one on the life cycle and mating behavior of the insect, another on the pheromone ecology of EAB and a paper on the classical biological control of the pest.

Knowledge of buprestid chemical ecology is sparse but the appearance of the invasive pest Agrilus planipennis Fairmaire in North America has provided the impetus to study in detail the semiochemistry and ecology of this important buprestid. The macrocyclic lactone (3Z)-12-dodecenolide [(3Z)-lactone] is identified as a key antennally-active compound that is produced by females and attracts males. Though a weak trap attractant alone, when combined with the host kairomone (3Z)-hexenol and the important visual cue of a green canopy trap, significant increases in male trap capture occur, thus defining (3Z)-lactone as both a sex pheromone of A. planipennis as well as the first and only known buprestid pheromone. The non-natural stereoisomer (3E)-12-dodecenolide and the saturated analog, 12-dodecanolide also exhibit mimetic activities towards male A. planipennis, suggesting a notable plasticity in this pheromonal structural motif. Efficient synthetic routes to these compounds have been developed. A series of fluoro-12-dodecanolides has also been synthesized containing CF2 groups as a strategy to bias the conformational space accessed by these macrolides and to assess if the analogs may act as mimetics for 12-dodecanolide pheromones associated in A. planipennis. These compounds also afford a unique opportunity to study the binding affinities of lactone surrogates with A. planipennis chemosensory proteins and olfactory receptors. Some progress has also been made in identifying the genes involved in the reception, processing and degradation of volatiles in this invasive insect. It is now evident that the behavior and ecology of A. planipennis involves a complex pattern of sensory modalities, including visual, tactile, olfactory and potentially acoustic components. Earlier reviews focused on studies of attractive host volatiles in development of a trapping system for early detection and visual and contact phenomena in A. planipennis mate finding. This review will update the semiochemistry and chemical ecology of A. planipennis and discuss studies on chemistry and behavior that have identified female-produced pheromone components and host kairomones. [ABSTRACT FROM AUTHOR]