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Invasive wood-boring insects are a major economic and ecological concern worldwide as they impact native woody plant populations. These pest species are increasing in prevalence, with devastating impact, as global trade leads to higher rates of introduction and establishment. The emerald ash borer (Agrilus planipennis; EAB) is one such species, which has caused widespread damage across much of the United States and is now spreading across Europe. Non-indigenous woodborers such as EAB are difficult to detect at early stages of invasion, which is when management and eradication efforts are most effective and cost efficient. Environmental DNA (eDNA) surveys have demonstrated power in detecting invasive species when rare in the landscape due to their ability to detect trace amounts of DNA and identify to species. Here, we trialled a novel eDNA method for collecting environmental samples within host trees where invasive pest larvae are feeding, using EAB as a case study. We extracted tree cores approximately 1 cm in length using an increment hammer to assess detectability of eDNA from larvae feeding under the bark. In trees visibly infested with EAB, we observed a seasonal peak in EAB DNA detection probability (~ 64%; towards the end of the growing season), indicating a potential impact of ash tree phenology or EAB phenology on detection. When we trialled the method in a site with ash trees of low or uncertain EAB abundance, we did not record positive EAB eDNA detections. This outcome may have resulted from differing EAB phenology at the northern latitude of this survey site or because larval galleries were less numerous causing EAB DNA to be scarcer within the tree. Our results, however, provide preliminary evidence that increment hammer tree cores can be used to detect eDNA of EAB and, perhaps, other wood-boring pests. Further work is needed to clarify false negative survey detections at ash trees showing little to no signs or symptoms of infestation, as well as investigating the deposition, transport and persistence dynamics of EAB eDNA within trees. [ABSTRACT FROM AUTHOR]

Non-Indigenous insects and pathogens (NIIP) have functionally eliminated numerous tree species of immeasurable cultural and ecological significance over the past century, with the number of species introductions and associated impacts growing each year. Foresters are often on the frontlines of these impacts, tasked with quickly adapting management plans to recover potential economic losses and maintain future silvicultural options following tree species loss. We highlight that the irreplaceable cultural and ecological values provided by many tree species argues for renewed focus on applying integrated pest management and adaptive strategies in novel ways to sustain these values for future generations. To guide these efforts, we describe a framework for adapting to NIIP centered on three interrelated components: preservation value, preservation approach, and preservation strategy. This framework and emerging species preservation efforts provide an alternative path forward to sustain threatened species and their associated values in an era of increasing change. Study Implications: The impact of non-indigenous insects and pathogens (NIIP) is one of the greatest challenges facing the long-term stewardship of forests in North America. Species preservation efforts that apply integrated pest management and adaptive strategies to maintain species in the face of NIIP are increasingly needed in foresters' toolboxes to address these novel threats. Identifying the preservation values (ethical responsibility, cultural integrity, ecological function, genetic conservation) tied to a species preservation effort will help guide how preservation approaches and strategies are applied at stand and landscape scales to sustain species and associated cultural and ecological values into the future. [ABSTRACT FROM AUTHOR]

The introduced emerald ash borer (EAB) represents the costliest invasive forest insect in US history, causing significant mortality of ash species across much of eastern North America as well as in Colorado and Oregon. Few surviving overstory ash trees exist in areas first invaded by EAB, such as the Lake States region; however, forests with healthy, mature ash remain in recently invaded regions, such as the northeastern United States. Given the importance of ash to cultural lifeways of Indigenous peoples and the ecology and economies of working forest lands, there is growing interest in applying protection measures to maintain ash in forested settings. We further develop our call for species preservation by presenting Indigenous and Western science case studies of ongoing efforts to mitigate the impacts of EAB, illustrating specific applications of these strategies for meeting different preservation goals in lowland and northern hardwood forests in northeastern North America. Study Implications: The introduced emerald ash borer (EAB) threatens to functionally eliminate ash species from large portions of the United States. Although the impacts of EAB are now widespread in many areas, portions of the United States, such as the Northeast, still contain forests with healthy, mature ash. This presents a unique opportunity to apply the integrated pest management strategies and knowledge gained from other invaded regions to preserve the cultural and ecological values provided by ash in the forest. Multistakeholder partnerships built around preserving the cultural and ecological values of ash have provided a powerful approach for sustaining ash into the future. [ABSTRACT FROM AUTHOR]

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a devastating, invasive insect pest of ash trees, Fraxinus spp., in North America. Using a simulation model, we evaluated three potential management options to slow the spread of A. planipennis in discrete outlier sites: (i) removing ash trees to reduce available host phloem resource, (ii) girdling ash trees to attract ovipositing female beetles and destroying the trees before larvae complete development, and (Hi) applying a highly effective systemic insecticide. Simulations indicate that systemic insecticide applications provided the greatest reduction in the radial spread of A. planipennis. In simulations in which management options were applied only within a 300 m radius from the origin of the infestation, insecticide applications reduced the radial spread by 30% and larval consumption of ash phloem by 40% beyond the treated area. In contrast, girdling ash trees reduced the radial spread by 15% and larval consumption of ash phloem by 20% beyond the treated area. Both of these management options significantly reduced the spread of A. planipennis when treatments were applied 1 to 4 years after infestations were initiated. Reducing ash phloem by removing ash trees decreased population size within treated areas but did not reduce the radial spread, population size, or larval consumption of ash phloem beyond treated areas. Resume: L'agrile du frene, Agrilus plenipennis Fairmaire (coleoptere, buprestides), est un insecte nuisible envahissant qui est devastateur pour le frene, Fraxinus spp., en Amerique du Nord. A l'aide d'un modele de simulation, nous avons evalue trois options potentielles de lutte pour ralentir la propagation d'A. plenipennis dans differents sites enclaves: (i) l'elimi-nation des frenes pour reduire la ressource disponible que constitue le phloeme de l'hote, (ii) l'annelation des frenes pour attirer les insectes femelles durant la periode d'oviposition et eliminer les arbres avant que les larves completent leur deve-loppement et (Hi) l'application d'un insecticide systemique tres efficace. Les simulations indiquent que les applications d'insecticide systemique reduisent le plus la propagation radiale d'A. plenipennis. Dans les simulations ou les options de lutte ont ete appliquees seulement a l'interieur d'un rayon de 300 m du point d'origine de l'infestation, les applications d'insecticide ont reduit la propagation radiale de 30 % et l'alimentation dans le phloeme du frene par les larves de 40 % au-dela de la zone traitee. Par contre, l'annelation des tiges de frene a reduit la propagation radiale de 15 % et l'alimen-tation dans le phloeme du frene par les larves de 20 % au-dela de la zone traitee. Ces deux options de lutte ont significati-vement reduit la propagation d'A. plenipennis lorsque les traitements etaient appliques un a quatre ans apres le debut des infestations. L'elimination des frenes pour reduire la quantite de phloeme disponible a diminue la taille de la population a l'interieur des zones traitees mais n'a pas reduit la propagation radiale, la taille de la population, ni l'alimentation dans le phloeme du frene au-dela des zones traitees. [Traduit par la Redaction], Introduction Nonindigenous invaders threaten biodiversity (Mack et al. 2000) and may profoundly affect evolutionary (e.g., Strauss et al. 2006) and community-ecosystem processes (e.g., Krushelnycky and Gillespie 2008). Invasive pests in [...]

The fungal pathogen Entomophaga maimaiga Humber, Shimazu et Soper has become an important biocontrol for gypsy moth (Lymantria dispar (L.)) in the northeastern United States and is commonly introduced into new areas with established gypsy moth populations. Germination of the fungus is dependent on spring temperature and moisture, but specific conditions associated with epizootics have not been determined. Whether E. maimaiga will be as effective in other regions that experience different weather conditions is not yet known. We examined similarity of weather conditions associated with 16 documented E. maimaiga epizootics with conditions at 1351 North American locations using the climate-matching software CLIMEX. Based on CLIMEX's overall index of climatic similarity, long-term annual climatic patterns across much of the eastern United States were 60%-80% similar to the conditions associated with epizootics. Monthly weather records from 1971 to 2000 in nine North Central states were examined to compare precipitation and temperature with conditions observed during epizootics. Based on climatic averages identified with the documented epizootics, temperature and precipitation conditions in Illinois, Indiana, Iowa, Kentucky, Missouri, and Ohio were more conducive for epizootics than conditions in Minnesota, Wisconsin, and Michigan, which were likely to support E. maimaiga epizootics in fewer than 6 of the 30 years considered. Le champignon pathogene Entomophaga maimaiga Humber, Shimazu et Soper est devenu un important moyen de lutte biologique contre la spongieuse (Lymantria dispar (L.)) dans le nord-est des Etats-Unis et est couramment introduit dans de nouvelles regions ou sont etablies des populations de spongieuse. La germination du champignon depend des conditions printanieres de temperature et d'humidite mais les conditions specifiquement associees aux epizooties n'ont pas ete determinees. On ne sait pas encore si E. maimaiga sera efficace dans d'autres regions ou les conditions meteorologiques sont differentes. Nous avons etudie la similitude entre les conditions meteorologiques associees a 16 epizooties documentees d'E. maimaiga et les conditions meteorologiques dans 1351 endroits en Amerique du Nord a l'aide du logiciel de comparaison du climat CLIMEX. Sur la base de l'indice general de similitude du climat de CLIMEX, les patrons annuels a long terme du climat a travers presque tout l'est des Etats-Unis sont de 60 a 80 % similaires aux conditions associees aux epizooties. Les donnees meteorologiques mensuelles de 1971 a 2000 dans neuf Etats du centre-nord ont ete examinees en comparant la temperature et les precipitations aux conditions observees lors des epizooties. Sur la base des moyennes observees lors des epizooties documentees, les conditions de temperature et les precipitations en Illinois, en Indiana, en Iowa, au Kentucky, au Missouri et en Ohio etaient plus propices aux epizooties que les conditions au Minnesota, au Wisconsin et au Michigan ou moins de six des 30 annees etudiees ont connu des conditions qui auraient pu entrainer une epizootie d'E. maimaiga. [Traduit par la Redaction], Introduction Substantial reductions in gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), defoliation in the northeastern United States in the last 10-15 years have been largely attributed to epizootics of Entomophaga [...]

We conducted a survey of 272 campers at 18 private and public campgrounds in Maine (n = 101), New Hampshire (n = 88), and Vermont (n = 83) to learn about their firewood movement behavior, and knowledge and beliefs about invasive forest pests. More than 25 percent of respondents reported that they often or always brought firewood from home for camping. Most (92 percent) had heard of invasive forest pests, but <25 percent could name an example without being prompted, affirming a need for increasing exposure of outreach materials to facilitate activation of attitudes associated with forest pests and transport of firewood. Campers provided helpful suggestions to improve current outreach and education efforts such as illustrating more of the detrimental impacts forest pests have on trees near homes or recreation areas. For campers who believe their wood is safe and therefore okay to transport regardless of regulations, a need exists to re-message arguments. Furthermore, results suggest that some campers with low involvement who are less engaged and less inclined to seek out information may additionally need more direct approaches. Actions to better capture the attention of these campers could potentially include confiscating illegally transported firewood at check stations, issuing warnings, or administering fines for moving nonlocal or nonheat-treated firewood in order to obtain compliance with protective firewood regulations. [ABSTRACT FROM AUTHOR]

We assessed density of emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) larvae over a 6-yr period by felling and sampling a total of 315 green ash (Fraxinus pennsylvanica Marsh.) trees that were left untreated or treated with imidacloprid, dinotefuran, or emamectin benzoate products at 1-yr, 2-yr, or 3-yr intervals. Our study, conducted across a 32-ha forested area, began soon after emerald ash borer became established and continued through the peak and eventual decline of the emerald ash borer population. Less than half of the 96 trees in the pretreatment sample were infested and larval densities were very low. Densities of emerald ash borer remained low for 3 yr, then increased exponentially, eventually resulting in mortality of most untreated overstory ash. Trees treated with either low or moderate rates of emamectin benzoate applied via trunk injection had few or no emerald ash borer galleries, even 3 yr post-treatment. Basal trunk sprays of dinotefuran applied annually were also effective at preventing larval densities from reaching damaging levels. Average larval densities on trees treated with a trunk injection of imidacloprid were lower but did not differ from untreated trees, regardless of treatment frequency. Larval parasitism was rare, while woodpecker predation was common and accounted for nearly all natural larval mortality, even on trees with very low densities of larvae. [ABSTRACT FROM AUTHOR]

Black ash ( Fraxinus nigra Marshall) trees are an important cultural resource and provide the wood used for traditional contemporary basketry by numerous Native American and First Nation tribes in the U.S.A. and Canada. The invasion and subsequent spread of emerald ash borer Agrilus planipennis Fairmaire ( Coleoptera: Buprestidae) threatens the ash resource in North America and the basketry tradition. Submersion of infested ash logs has been proposed as a potential tactic to control A. planipennis emergence, although the duration of submergence required to prevent adult beetle emergence is unknown., We assessed the survivorship of A. planipennis prepupae through adult beetle emergence in green ash ( F. pennsylvanica Marshall) bolts submerged at weekly intervals for up to 6 weeks and in black ash bolts submerged at 4-week intervals for up to 24 weeks. The moisture content of sapwood at depths where prepupal chambers are commonly found was quantified in the black ash bolts after 0, 12 and 24 weeks of submergence., Mortality of A. planipennis from prepupa to adult was low (5.7 ± 2.3%) for the first 6 weeks of submersion but rapidly increased to 100% in green ash and black ash bolts submerged for 8 weeks or longer. In black ash, the outer 1.3 cm of wood became highly saturated after submersion for 12 weeks (81.0 ± 4.5%) and moisture increased only slightly after 24 weeks (83.9 ± 2.8%)., The results obtained in the present study indicate that A. planipennis prepupae in green ash and black ash bolts can survive complete submersion for extended periods of time (i.e. at least 6 weeks) and successfully emerge as adults afterwards. Logs submerged for at least 8 weeks, however, produced no live A. planipennis beetles, indicating that submersion represents an efficacious control option. [ABSTRACT FROM AUTHOR]

Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky), is an invasive insect that has successfully established multiple times in North America. To investigate host colonization and reproductive success (exit holes/eggs), two ALB infested forest stands were sampled in central Massachusetts, USA. Infested Acer platanoides L., Acer rubrum L., and Acer saccharum Marsh. were felled, bucked into 1 m sections and dissected to determine indications of ALB infestations, such as presence of life stages or signs of damage on trees. ALB damage was also aged on a subset of trees to determine the earliest attacks on the three Acer species. In one stand, ALB oviposition was significantly higher on the native A. rubrum and A. saccharum than the exotic A. platanoides. In the second stand, ALB oviposition was significantly higher and cumulative reproductive success was higher on A. rubrum than A. platanoides or A. saccharum. An A. saccharum had the earliest signs of attack that occurred in 2006. Acer rubrum (2007) and A. platanoides (2010) were colonized shortly thereafter. Overall, ALB was more successful in A. rubrum, where adults emerged from 53% and 64% of trees in each stand, compared to A. platanoides (11% and 18%) or A. saccharum (14% and 9%).; [ABSTRACT FROM AUTHOR]

The fungal entomopathogen Entomophaga maimaiga has provided important biological control of gypsy moth, Lymantria dispar (L.), since the first epizootics occurred in the northeastern United States in 1989. Epizootics are initiated by germination of soil-bonm resting spores, which are highly sensitive to spring temperature and moisture. We compared gypsy moth infection by E. maimaiga in 33 oak stands in Michigan with infection under optimal laboratory conditions from 1999 to 2001 to assess differences between potential and realized efficacy of E. maimaiga. Field bioassays were conducted by exposing laboratory-reared, fourth-instar gypsy moth to soil at the base of oak trees for 4 d. Additional larvae were similarly exposed to soil collected from the field plots in laboratory bioassays with temperature, humidity, and moisture levels optimal for fungal germination. Overall E. maimaiga infection ranged from means of 3.2-29.8% in the field compared with 20.9-59.7% in the laboratory during three field seasons. Resting spore density in soil and gypsy moth egg mass density were significant predictors of field infections in two of the 3 yr, whereas resting spore density was a significant predictor of laboratory infections each year. Other variables that significantly predicted laboratory infections in one of the 3 yr included egg mass density, canopy cover, and soil pH. In laboratory bioassays, soil pH and E. maimaiga resting spore density were positively associated with increasing E. maimaiga infection rates of gypsy moth larvae. [ABSTRACT FROM AUTHOR]

1 Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive forest insect pest threatening more than 8 billion ash ( Fraxinus spp.) trees in North America. Development of effective survey methods and strategies to slow the spread of A. planipennis requires an understanding of dispersal, particularly in recently established satellite populations. 2 We assessed the dispersal of A. planipennis beetles over a single generation at two sites by intensively sampling ash trees at known distances from infested ash logs, the point source of the infestations. Larval density was recorded from more than 100 trees at each site. 3 Density of A. planipennis larvae by distance for one site was fit to the Ricker function, inverse power function, and the negative exponential function using a maximum likelihood approach. The prediction of the best model, a negative exponential function, was compared with the results from both sites. 4 The present study demonstrates that larval densities rapidly declined with distance, and that most larvae (88.9 and 90.3%) were on trees within 100 m of the emergence point of the adults at each site. The larval distribution pattern observed at both sites was adequately described by the negative exponential function. [ABSTRACT FROM AUTHOR]

Emerald ash borer,Agrilus planipennis Fairrnaire (Coleoptera: Buprestidae), aphloem-feeding pest native to Asia, was identified in June 2002 as the cause of widespread ash (Fraxinus spp.), mortality in southeastern Michigan and Windsor, Ontario, Canada. Localized populations of A. planipennis have since been found across lower Michigan and in areas of Ohio, Indiana, Illinois, Maryland, and Ontario. Officials working to contain A. planipennis and managers of forestlands near A. planipennis infestations must be able to compare alternative strategies to allocate limited funds efficiently and effectively. Empirical data from a total of 148 green ash, Fraxinus pennsylvanica Marsh., and white ash, Fraxinus americana L., trees were used to develop models to estimate surface area of the trunk and branches by using tree diameter at breast height (dbh). Data collected from 71 additional F. pennsylvanica and F. americana trees killed by A. planipennis showed that on average, 88.9 ± 4.6 beetles developed and emerged per m² of surface area. Models were applied to ash inventory data collected at two outlier sites to estimate potential production of A. planipennis beetles at each site. Large trees of merchantable size (dbh ≥ 26cm) accounted for roughly 6% of all ash trees at the two sites, but they could have contributed 55–65% of the total A. planipennis production at both sites. In contrast, 75–80% of the ash trees at the outlier sites were ≤13 cm dbh, but these small trees could have contributed only ≤12% of the potential A. planipennis production at both sites. Our results, in combination with inventory data, can be used by regulatory officials and resource managers to estimate potential A. planipennis production and to compare options for reducing A. planipennis density and slowing the rate of spread for any area of interest. [ABSTRACT FROM AUTHOR]

Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky), is an invasive insect that has successfully established multiple times in North America. To investigate host colonization and reproductive success (exit holes/eggs), two ALB infested forest stands were sampled in central Massachusetts, USA. Infested Acer platanoides L., Acer rubrum L., and Acer saccharum Marsh. were felled, bucked into 1 m sections and dissected to determine indications of ALB infestations, such as presence of life stages or signs of damage on trees. ALB damage was also aged on a subset of trees to determine the earliest attacks on the three Acer species. In one stand, ALB oviposition was significantly higher on the native A. rubrum and A. saccharum than the exotic A. platanoides. In the second stand, ALB oviposition was significantly higher and cumulative reproductive success was higher on A. rubrum than A. platanoides or A. saccharum. An A. saccharum had the earliest signs of attack that occurred in 2006. Acer rubrum (2007) and A. platanoides (2010) were colonized shortly thereafter. Overall, ALB was more successful in A. rubrum, where adults emerged from 53% and 64% of trees in each stand, compared to A. platanoides (11% and 18%) or A. saccharum (14% and 9%).