Extracts of Diprion similis females contained about 15 ng of the sex pheromone precursor 3,7-dimethylpentadecan-2-ol per female. After derivatisation with (S)-2-acetoxypropanoyl chloride, we found that the major stereoisomer in the extract was (2S,3R,7R)-3,7-dimethylpentadecan-2-ol. Small amounts of other stereoisomers of 3,7-dimethylpentadecan-2-ol were also identified in the extract, namely 1% of (2R,3S,7S), 0.3% (2R,3R,7R) and 0.4% of (2R,3R,7S). An unknown fifth substance showed a very similar spectrum to 3,7-dimethylpentadecan-2-ol, both in SIM and full scan mode. None of the earlier suggested behavioural synergistic isomers ((2S,3S,7S), (2S,3S,7R) and (2S,3R,7S)) were detected in the extracts. In field tests in Ontario, Canada, the earlier identified main pheromone component, viz. the propanoate of (2S,3R,7R)-3,7-dimethylpentadecan-2-ol, was tested alone and in combination with other stereoisomers, earlier reported to be synergistic. No synergistic effects were detected and the threo four-isomer blend was as attractive as the pure main compound. Thus, one of the few examples of a diprionid sawfly using more than one substance in its sex pheromone could not be confirmed. The results also suggest that monitoring programs can use the more easily synthesized threo-blend without losing efficiency. Furthermore, the study suggests that other diprionid pheromones may benefit from a reinvestigation, to clarify possible synergistic effects of stereoisomers.

Populations of native North American parasitoids attacking Agrilus Curtis (Coleoptera: Buprestidae) species have recently been considered as part of an augmentative biological control programme in an attempt to manage emerald ash borer, Agrilus planipennis Fairmaire, a destructive wood-boring beetle discovered in North America in 2002. We evaluate trapping methods to detect and monitor populations of two important native larval parasitoids, Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae) and Atanycolus Forster (Hymenoptera: Braconidae) species, attacking emerald ash borer in its introduced range. We found that purple prism traps captured more P. sulcata than green prism traps, yellow pan traps, and log samples and thus were considered better for detecting and monitoring P. sulcata populations. Trap type did not affect the number of captures of Atanycolus species. Surprisingly, baiting prism traps with a green leaf volatile or manuka oil did not significantly increase captures of P. sulcata or Atanycolus species. Based on these results, unbaited purple prism traps would be optimal for sampling these native emerald ash borer parasitoids in long-term management programmes.

Emerald ash borer (EAB; Agrilus planipennis, Coleoptera: Buprestidae) causes large economic costs by killing ash trees (Fraxinus spp.): a process that takes several years of infestation. We suggest that the most important prediction regarding this species is not whether EAB can persist indefinitely in a new region, but whether it can persist long enough to kill trees. We use a mechanistic model of overwintering mortality of EAB prepupae to identify Canadian cities and more generally, those areas of North America at risk of impact. Although we have previously used a Newtonian cooling model to predict underbark temperatures of ash from meteorological data, we show that a linear regression model has smaller errors for the low winter temperatures relevant to EAB mortality. Using this regression model we generate distributions of predicted underbark temperatures which we then use to predict the return time of weather events cold enough to cause either complete (99%) or partial (75%) mortality of overwintering EAB prepupae. We find that most of North America does not experience extreme cold events frequently enough to prevent ash mortality from EAB (i.e., more frequently than every 6 years), and therefore conclude that large economic impacts are likely throughout the continent. However, if relatively frequent partial mortality events are sufficient to reduce ash mortality, there is a possibility of northern refugia for ash species, and some northern Canadian sites may escape the costs of this non-native pest.

We evaluated the use of fluorescent powders for tracking dispersal by the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), of Beauveria bassiana isolates from an autocontamination device. Neither of the two DayGlow powders tested (Arc Yellow and Aurora Pink) interfered with fungal germination or growth, nor did they affect survival of beetles in the laboratory, or affect virulence of the fungus. The powders persisted at least 10 days out-of-doors on dead beetles in sticky band traps, and at least 14 days on pouches inside autocontamination traps. During field trials of autocontamination traps with powder-dusted fungal pouches in southwestern Ontario, 8.0% of the 4010 beetles captured in green prism and sticky-band traps were positive for fluorescent powders. Only half (46.2-57.8%) of the powder-positive beetles actually carried viable fungal conidia, as determined by plating of beetle rinses, possibly as a result of patchy growth of fungal isolates and reduced conidia production on pouch surfaces during the 16-day trapping experiment. The presence of viable conidia (either one or both isolates) on about 10% of beetles that did not carry any visible powder particles may be an indication of horizontal transmission of the fungus by beetles that had visited the autocontamination traps.

Under laboratory and field conditions in Ontario, Canada, we explored the natural history of Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae), an indigenous solitary endoparasitoid of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in North America. Adult P. sulcata emergence was similar to 20.2-23.9 days after host emergence at 21 degrees C, with P. sulcata females emerging an similar to 5.4-5.8 days before males. Females also represented 61.8 and 67.0% of emerging adults in the two years sampled. Mean adult longevities for males and females of P. sulcata were 23.8 +/- 1.10 and 28.9 +/- 1.11 days at 21 degrees C, respectively. Mean potential fecundity of P. sulcata at emergence was 55.7 +/- 2.9 eggs per female. Based on adult emergence, parasitism at two sites varied from 11.7% to 34.4%. Adult parasitoids were first observed in the field in early June, with peak capture occurring in late June. Parasitism rates in A. planipennis-infested ash trees was not affected by tree height below 360 cm, whereas parasitism was not observed at heights > 360 cm. Our results suggest that although mass rearing will be challenging, observed parasitism rates in conjunction with temporal and spatial synchrony indicate that indigenous P. sulcata may be an important source of mortality for A. planipennis populations.

Ptosima Dejean, 1833 (Coleoptera: Buprestidae) (Fig. 1) contains 10 extant species worldwide (Bellamy 2008) with four species occurring in North American (Nelson 1978, Nelson et al. 2008). Nelson (1978) keyed and redescribed the North American species. Plant genera records for Ptosima spp. include Crataegeus (Rosaceae), Cercis (Fabaceae) and Quercus (Fagaceae) (Paiero et al. 2012). Ptosima idolynae Frost, 1923 and P. laeta Waterhouse,1882 are confined to south central North America, whereas P. gibbicollis (Say, 1823) and P. walshii LeConte, 1863 are widely distributed in eastern North America. Bright (1987) stated that P. gibbicollis “probably occurs in southern Ontario”, but makes no mention of P. walshii. Paiero et al. (2012) mapped the distribution of P. gibbicollis as occurring in Ontario. They also mapped the host range of P. walshii, as a potential distributional range for the beetle, encompassing Manitoba, Ontario and Quebec, but no records were known for these Provinces. Ptosima walshii is considered “rarely collected” (MacRae 2006) and “infrequently encountered” (Paiero et al. 2012). Nelson (1978) stated that P. walshii had been reported from Illinois, Texas, Kansas and California, suggested that the California record was doubtful, and added new State distribution records for Iowa, Michigan, Minnesota, Mississippi, Missouri, Ohio and Wisconsin. Westcott (1991) provided compelling evidence that the California record was erroneous. Records for four states that border Canada—Michigan, Ohio, Wisconsin and Minnesota—are represented by a total of eight collections (Nelson 1978). The Michigan record was a single collection labeled “Ag. Coll. 20.V.1889” (Nelson 1978). Westcott (1991) reported a specimen from Oklahoma. Thus, the literature records confirmed by specimens include 11 States but no Provinces. As part of a trapping study for the recently discovered European oak borer, Agrilus sulcicollis Lacordaire (Coleoptera: Buprestidae) in North America (Jendek and Grebennikov 2009, Haack et al. 2009), we collected numerous P. walshii adults in southwestern Ontario. These collections represent the first verified records of the species

Biological control has been an important tactic in the management of Canadian forests for over a century, but one that has had varied success. Here, we review the history of biological control programmes using vertebrate and invertebrate parasitoids and predators against insects in Canadian forests. Since roughly 1882, 41 insect species have been the target of biological control, with approximately equal numbers of both native and non-native species targeted. A total of 161 species of biological control agents have been released in Canadian forests, spanning most major orders of insects, as well as mites and mammals. Biological control has resulted in the successful suppression of nine pest species, and aided in the control of an additional six species. In this review, we outline the chronological history of major projects across Canadian forests, focussing on those that have had significant influence for the development of biological control. The historical data clearly illustrate a rise and fall in the use of biological control as a tactic for managing forest pests, from its dominance in the 1940s and 1950s to its current low level. The strategic implementation of these biological control programmes, their degree of success, and the challenges faced are discussed, along with the discipline's shifting relationship to basic science and the environmental viewpoints surrounding its use.

AbstractPhasgonophora sulcataWestwood (Hymenoptera: Chalcididae) is a North American parasitoid now usingAgrilus planipennisFairmaire (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 ofP. 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 ofP. sulcatapopulations.

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.

AbstractEmerald ash borer,Agrilus planipennisFairmaire (Coleoptera: Buprestidae), is an Asian species that was introduced into North America in the mid-1990s. The beetle has the potential to devastate populations ofFraxinusLinnaeus (Oleaceae) species. Several species of Hymenoptera parasitoids have made the transition from North AmericanAgrilusCurtis hosts toA. planipennis, and some (e.g.,AtanycolusFörster (Hymenoptera: Braconidae) species) have caused substantial mortality. Invertebrate predators ofA. planipennishave been poorly investigated. Predation by woodpeckers (Aves: Picidae) has had the greatest impact onA. planipennispopulations. Native entomopathogens have also been observed in populations ofA. planipennisand are being explored as potential biological control agents.Agrilus planipennisis 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 ofFraxinuspossess some resistance toA. planipennisvia defensive mechanisms, but these are quickly overcome by expanding larval populations. Intraspecific competition (via cannibalism and starvation) impacts larval survival.

In this study we demonstrate how the notion of diversification can be used in broad-scale resource allocation for surveillance of invasive species. We consider the problem of short-term surveillance for an invasive species in a geographical environment. We find the optimal allocation of surveillance resources among multiple geographical subdivisions via application of a classical portfolio framework, which allocates investments among multiple financial asset types with uncertain returns in a portfolio that maximizes the performance and, by meeting the desired diversification targets, protects against errors in estimating the portfolio's performance.We illustrate the approach with a case study that applies a spatial transmission model to assess the risk of spread of the emerald ash borer (EAB), a significant pest in North America, with infested firewood that may be carried by visitors to campground facilities in central Canada. Adding the diversification objective yields an expected survey performance that is comparable with undiversified optimal allocation, but more importantly, makes the geographical distribution of survey priorities less subject to possible errors in the spread rate estimates. Overall, diversification of pest surveillance can be viewed as a viable short-term strategy for hedging against uncertainty in expert- and model-based assessments of pest invasion risk. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.

Abstract This chapter focuses on pine false webworm (Acantholyda erythrocephala) attacking Pinus spp. in Canada, and provides an overview of the biological control agents and parasitoids that have been used to date for its management, the release of the larval parasitoid Myxexoristops hertingi, and the evaluation of effectiveness of Trichogramma platneri, Trichogramma minutum and Trichogramma acantholydae. Future research prospects are recommended.

The emerald ash borer (EAB) (Agrilus planipennis Fairmaire) (Coleoptera; Buprestidae), is an invasive wood-boring beetle native to northeast Asia. This species was first detected in Michigan USA in 2002, and is a significant threat to native and ornamental ash tree species (Fraxinus spp.) throughout North America. We characterized seven polymorphic microsatellite markers for EAB and used these to investigate EAB population structure in the early invasive populations within North America and in comparison with Asia. We found 2–9 alleles per microsatellite locus, no evidence of linkage disequilibrium, and no association with known coding sequences, suggesting that these markers are suitable for population genetic analysis. Microsatellite population genetic structure was examined in 48 EAB populations sampled between 2003 and 2008 from five regions, three in the introduced range, Michigan (US) and Ontario and Quebec (Canada) and two Asian regions, China and South Korea, where EAB is native. We found significant genetic variation geographically but not temporally in EAB populations. Bayesian clustering analyses of individual microsatellite genotypes showed strong clustering among multiple North American populations and populations in both China and South Korea. Finally, allelic richness and expected heterozygosity were higher in the native range of EAB, but there was no difference in observed heterozygosity, suggesting a significant loss of alleles upon introduction but no significant change in the distribution of alleles within and among individuals.

We use two ecological niche modeling methods, Maxent and GARP, to model the potential distribution of emerald ash borer (Agrilus planipennis, EAB) in its invaded (Canada, USA) and native range (eastern Asia). For each algorithm (Maxent and GARP), we constructed three different models based on native or invaded data or a combination thereof. All GARP models yielded higher area under the curve (AUC) values and had therefore higher discriminatory power than the corresponding Maxent models, and the area predicted as suitable by GARP in North America was generally larger and included most infested sites even at the known range edges. In Asia, habitat suitability predicted by both algorithms was low and models trained with invaded coordinates did not transfer well to the native range. We found that none of the Maxent models provided a prediction precise enough for reliable risk assessment and the development of management plans, but a GARP model trained in the native range performed well when validated with data from the invaded range. Based on this GARP model, EAB may be able to extend its North American range further south, north and west covering roughly half (49%) of the natural range of the most common affected ash species (Fraxinus americana, F. nigra, F. quadrangulata, and E. pennsylvanica). While our results demonstrate that native data may be useful for risk assessment of invasive species, a validation of early predictions based on these data is only possible with a time lag, which is lacking for most species. Due to uncertainties associated with ecological niche models for invaders, native data may not be sufficient at all times for long-term risk assessment. With regard to the latter, we recommend frequent re-evaluation of models based on more current monitoring. Combining ecological niche models with more mechanistic approaches based on experimental data may reduce uncertainty and improve risk assessment. (C) 2012 Elsevier B.V. All rights reserved.

Emerald ash borer (EAB) is an invasive phloem-feeding insect causing extensive mortality to ash (Fraxinus sp.) in North America. Economic costs associated with EAB-related mortality of street and backyard trees in Canadian urban areas were estimated over a 30-year time horizon. The approach employed a simple spread model to approximate EAB arrival times at each community based on three maximum spread rates: slow (~10 km/year), medium (~30 km/year), and fast (~50 km/year). Costs are estimated for four discount rates (0%, 2%, 4%, and 10%) and three treatment rates (0%, 10%, and 50% of trees treated with an insecticide). Ash density along urban roads was estimated from a variety of sources, including a recently developed survey that allows for rapid assessment of street tree compositions. Based on the 30 km/year spread rate, a 4% discount rate, and a 10% treatment rate, the present value of the costs is estimated to be approximately CAD $524 million (2010 currency rate); this value increases to roughly $890 million when costs associated with backyard trees are included. These estimates are conservative because they focus only on damage to street (and backyard) trees; nonetheless, their magnitude suggests considerable justification for investments to slow the spread of EAB in Canada.

Most studies of under-bark microclimate have been restricted to observations of a few coniferous trees in wooded locations. The findings of these studies may not generalize to deciduous hardwood trees, or to trees in urban environments. We addressed this limitation with a large data set of under-bark temperatures of ash trees (Fraxinus spp.) in urban and woodlot environments at six different Ontario locations. We observed that daily minimum under-bark temperatures of these deciduous trees are significantly warmer than daily minimum air temperatures in the winter, and that these differences can be important to predictions of overwintering mortality of wood-boring beetles during cold periods. The difference between air and under-bark temperature minima can vary considerably, and we observed that, on 17% of days in the winter of 2008-2009, minimum under-bark temperatures differed by more than 4 degrees C from minimum air temperatures on the north side of woodlot trees (the most conservative value found). With such large differences relatively common, we conclude that assumptions of a constant level of temperature difference between the under-bark microclimate and air temperature are not valid. There were significant differences between under-bark temperature minima in urban and woodlot environments, but the small magnitude of these differences (<0.5 degrees C) suggests that urban heat island effects will not significantly influence beetle overwintering survival, at least for urban trees bordering a park or yard. Spring maxima under-bark temperatures on the south side of trees were significantly warmer than air temperature maxima, but not for the north side of the trees. This difference leads to significantly faster predicted development times for beetles on the south side of urban trees. However, no difference was found between development times predicted using air temperature and under-bark temperatures for the south side of woodlot trees. Clearly, solar loading leads to faster development rates, and as a result, we suggest urban trees in exposed areas may alter the projected population dynamics of wood-boring insects in wider regions. (C) 2012 Elsevier B.V. All rights reserved.

Aim Uncertainty has been widely recognized as one of the most critical issues in predicting the expansion of ecological invasions. The uncertainty associated with the introduction and spread of invasive organisms influences how pest management decision makers respond to expanding incursions. We present a model-based approach to map risk of ecological invasions that combines two potentially conflicting goals: (1) estimating the likelihood of a new organism being established at a given locale and (2) quantifying the uncertainty of that prediction.Location Eastern and central Canada.Methods Our methodology focuses on the potential for long-distance, human-assisted spread of invasive organisms. First, we used a spatial simulation model to generate distributions of plausible invasion outcomes over a target geographical region. We then used second-degree stochastic dominance (SSD) criteria to rank all geographical locations in the target region based on these distributions. We applied the approach to analyze pathways of human-assisted spread (i.e., with commercially transported goods) of the emerald ash borer (EAB) (Agrilus planipennis Fairmaire), a major pest of ash trees in North America.Results The projected potential of the pest to establish at remote locations is significantly shaped by the amount of epistemic uncertainty in the model-based forecasts. The estimates based on the SSD ranking identified major 'crossroads' through which the movement of the EAB with commercial transport is most likely to occur. The system of major expressways in Ontario and Quebec was confirmed as the primary gateway of the pest's expansion throughout the Canadian landscape.Main conclusions Overall, the new approach generates more realistic predictions of long-distance introductions than models that do not account for severe uncertainties and thus can help design more effective pest surveillance programmes. The modelling technique is generic and can be applied to assess other environmental phenomena when the level of epistemic uncertainty is high.

The emerald ash borer (Agrilus planipennis, Coleoptera: Buprestidae) is a wood-boring invasive pest devastating North American ash (Fraxinus spp.). A. planipennis overwinters primarily as a freeze-avoiding prepupa within the outer xylem or inner bark of the host tree. The range of this species is expanding outward from its presumed introduction point in southwestern Michigan. We hypothesized that loss of cold tolerance in response to mid-winter warm spells could limit survival and northern distribution of A. planipennis. We determined whether winter-acclimatised A. planipennis prepupae reduced their cold tolerance in response to mid-winter warm periods, and whether this plasticity was reversible with subsequent cold exposure. Prepupae subjected to mid-winter warm spells of 10 and 15°C had increased supercooling points (SCPs) and thus reduced cold tolerance. This increase in SCP was accompanied by a rapid loss of haemolymph cryoprotectants and the loss of cold tolerance was not reversed when the prepupae were returned to −10°C. Exposure to temperatures fluctuating from 0 to 4°C did not reduce cold hardiness. Only extreme warming events for several days followed by extreme cold snaps may have lethal effects on overwintering A. planipennis populations. Thus, distribution in North America is likely to be limited by the presence of host trees rather than climatic factors, but we conclude that range extensions of invasive species could be halted if local climatic extremes induce unidirectional plastic responses.