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Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) is an important egg parasitoid of the emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Methods for laboratory-rearing O. agrili have been developed but its mass-production depends on the continuous production and storage of freshly laid EAB eggs as well as diapaused parasitoid progeny (inside parasitized EAB eggs). The purpose of this study was to determine optimal environmental conditions for long-term storage of host eggs as well as diapaused parasitoid progeny. Fresh host eggs and diapaused parasitoid progeny were stored at two low storage temperatures (1.7 and 12.8 °C) and three levels of relative humidity (low ∼31%, medium ∼74%, and high ∼99.9%) for various length of time (15–270 days) and then evaluated for host egg suitability and the reproductive fitness of stored parasitoid progeny. EAB eggs were stored for approximately 30 days without significant reduction of their viability and suitability to O. agrili parasitism at low storage temperatures under high and medium relative humidity. Neither storage temperature or humidity had any significant effects on adult parasitoid emergence for storage durations of up to 270 days. When storage durations were over 120 days, however, both adult parasitoid longevity and fecundity declined approximately 20–30% across all temperature and humidity treatments. Relevance of findings to mass-production and storage of O. agrili for biocontrol is discussed. [ABSTRACT FROM AUTHOR]

The genus Agrilus is one of the most diverse insect genera worldwide. The larval feeding activity causes extensive damage in both forests and orchards. In addition, more than 30 species have been introduced outside their native range so far, including the emerald ash borer Agrilus planipennis Fairmaire. Thus, the availability of efficient trapping protocols for early detection of Agrilus species at entry points is of utmost importance. In this study we tested whether trapping protocols developed for surveillance of A. planipennis in North America were also effective for other Agrilus species. In particular, through a multi-country assessment we compared the efficacy of detecting Agrilus species on: (i) green glue-coated prism traps vs. green Fluon-coated multi-funnel traps when baited with the green leaf volatile (Z)-3-hexenol or left unbaited; and (ii) green multi-panel traps vs. green multi-panel traps baited with dead adult Agrilus beetles (decoys). A total of 23,481 individuals from 45 Agrilus species were caught. Trap design significantly affected both species richness and abundance of Agrilus species in several of the countries where the trapping experiments were carried out, and green prism traps outperformed green multi-funnel traps in most cases. On the contrary, the addition of a (Z)-3-hexenol lure or dead adult beetle decoys on to traps did not improve trap catches. Our study highlights that reliable trap models to survey Agrilus species are already available, but also that there is the clear need to further investigate chemical ecology of Agrilus species to develop semiochemical lures that can improve detection efficacy. [ABSTRACT FROM AUTHOR]

Emerald ash borer (EAB) (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is the most destructive insect to invade North American forests. Identifying habitat features that support EAB natural enemies is necessary to enhance EAB biological control. In many forest ecosystems, tree species diversity has been linked with reduced pest abundance and increases in natural enemy abundance. We assessed the influence of tree species richness, ash density, and proportion of total ash basal area on ash canopy condition, EAB larval densities, and biocontrol by woodpeckers and parasitoids in pairs of healthy and declining overstory (DBH > 10 cm) and recruit-sized ash (DBH 2–10 cm) in 4 post-invasion forests in Michigan, USA. Tree species richness and ash density were not significantly associated with EAB larval densities, ash canopy dieback and transparency, and woodpecker predation of EAB larvae. In declining and healthy overstory ash, woodpeckers killed 38.5 ± 3.9% and 13.2 ± 3.7% of larvae, respectively, while the native parasitoid Phasgonophora sulcata Westwood killed 15.8 ± 3.8% and 8.3 ± 3.0% and the introduced parasitoid Spathius galinae Belokobylskij & Strazanac killed 10.8 ± 2.5% and 5.0 ± 2.6% of EAB larvae. Parasitism by P. sulcata was inversely related to ash density while parasitism by S. galinae was positively associated with ash density. Ash density, but not tree diversity, appears to differentially influence biological control of EAB by parasitoids, but this effect is not associated with reduced EAB densities or improved canopy condition. [ABSTRACT FROM AUTHOR]

Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has caused extensive mortality of ash across North America. Biological control offers a potential long-term management option, allowing for long-term survival of ash. Careful monitoring of populations of biocontrol agents is necessary to understand their relative impacts. Understanding the emergence and flight phenology of these species allows for the optimization of monitoring schemes and improves our understanding of host–parasitoid interactions. We used yellow pan trapping data to assess the adult phenology of both EAB and its associated native and introduced parasitoids in 3 New York counties. We monitored 2 introduced larval biocontrol agents, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius galinae Belokobylskij & Strazanac (Braconidae), for 3–4 years post-release, as well as the native parasitoid Phasgonophora sulcata Westword (Chalcididae). Results indicate a single discrete emergence event for both EAB and P. sulcata in all monitored counties, which is consistent with previously reported results. Our results also suggest there are 4 generations per year of T. planipennisi and 3 generations of S. galinae in the monitored counties. We recorded an additional generation of T. planipennisi that had not previously been reported in New York, and both T. planipennisi and S. galinae appeared to emerge earlier than previously documented. [ABSTRACT FROM AUTHOR]

The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is one of the most destructive invasive forest pests in North America, where it has killed hundreds of millions of ash (Fraxinus spp.) trees since its first detection in 2002. Native to Asia, female EAB adults lay their eggs between bark crevices or under loose bark of their host trees. Because of this cryptic egg-laying behavior, field detection of EAB eggs has been extremely difficult, resulting in knowledge gaps of EAB egg-laying behavior. In the present study, I tested the potential use of strips of burlap fabric (0.03 m × 1 m) or polypropylene curling ribbon (0.005 m × 2 m) to induce female EAB adults to lay eggs on the trunks or branches of ash covered with these materials in the field. The burlap trap tested in this study detected more than twice as many EAB eggs (4.9 ± 1.1 eggs per burlap trap) as did the polypropylene ribbon trap (1.9 ± 0.5 eggs per ribbon trap). When the surface area of each trap is standardized to one square meter, however, both burlap fabric and polypropylene ribbon traps are equally effective in inducing female EAB adults to lay eggs onto the covered surface of ash trunks or branches. Potential applications of the oviposition traps for effective detection and control of EAB and other jewel beetles are discussed. [ABSTRACT FROM AUTHOR]

The lethal heat treatment dose (time and temperature) for the prepupal life stage of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), emerald ash borer (EAB), was determined through an in vitro application using a carefully calibrated heat treatment apparatus.The lethal and sublethal effects of heat on A. planipennis prepupae were assessed through a ramped heat delivery application, simulating industrial kilns and conventional heat chamber operations, for treatments combining target temperatures of 54 °C, 55 °C, and 56 °C, and exposure durations of 0 min (i.e., kiln temperature ramp only), 15 min, or 30 min. Prepupal EAB larvae did not survive exposure to 56 °C for 15 min or longer, or to 55 °C for 30 min. Sublethal effects were observed for all other treatments. Sublethal effects included delayed development and failure to complete the pupal and adult life stages. [ABSTRACT FROM AUTHOR]

We examined the health of mature blue ash, Fraxinus quadrangulata, in two forests in southwestern Ohio in relation to that of mature white ash, F. americana, and examined the potential importance of oviposition preferences and larval resistance in the persistence of blue ash.Both blue ash and white ash were largely unaffected by emerald ash borer in 2012. By 2018, nearly 90% of the blue ash trees observed in these forests had full or nearly full canopies, as opposed to less than 20% of the white ash encountered in our studies. In 2021, blue ash maintained a similar degree of canopy health as in 2018, but no standing live mature white ashes remained.Bark removals revealed no current or past larval feeding attempts in blue ash in 2018 or 2021, except for one attacked and killed tree in 2018. All white ash trees examined were attacked. In a laboratory bioassay with cut stems, emerald ash borer larvae fed less and grew significantly more slowly on blue ash than on white ash.Both reduced larval performance and reduced adult oviposition likely contribute to the persistence of blue ash in forests devastated by emerald ash borer. [ABSTRACT FROM AUTHOR]

Spathius galinae is a larval parasitoid native to the Russian Far East that was approved for release in the United States in 2015 for biological control of the emerald ash borer (EAB), Agrilus planipennis , an invasive beetle from Asia responsible for widespread mortality of ash trees (Fraxinus spp.) in North America. From 2015 to 2017, 1,340–1,445 females of S. galinae along with males were released into each release plot, paired with a nonrelease control plot (1–12.5 km apart), at 6 postinvasion forested sites containing abundant pole-sized ash trees in Michigan. By 2018, S. galinae had spread to all but one control plot. Based on the first year that S. galinae was found in trees in each control plot and the distances of those trees to the parasitoid release point within each site, we estimated that S. galinae spread at 3.7 (±1.9) km per year after its initial releases in 2015. The proportion of sampled trees with S. galinae broods, brood densities within sampled trees, and parasitism of EAB larvae increased sharply in both control and release plots after the last field releases in 2017, with the highest parasitism rates (42.8–60.3%) in 2020. Life table analysis showed that S. galinae alone reduced EAB's net population growth rate by 35–55% across sites from 2018 to 2020. These results demonstrate that S. galinae has established an increasing population in Michigan and now plays a significant role in reducing EAB populations in the area. [ABSTRACT FROM AUTHOR]

Exclusivity evaluation on specimens: 100% Primer specificity was evaluated using the LAMP test and PCR against non-target I A. anxius i , I A. bilineatus i , I A. sulcicollis i , I A. subcinctus i , I D. ponderosae i , and I D. rufipennis i (adults). The only species which are similarly large are: I Agrilus ater i , I A. biguttatus i , I A. guerini i , I A. mendax i , I A. sinuatus i , I A. subauratus i , I A. suvorovi i and I A. viridis i . Among the species which may attack I Fraxinus i trees, I A. convexicollis i , I A. graminis i , I A. cyanescens i , and I A. roscidus i are much smaller than I A. planipennis i and have a different abdominal segment shape (Volkovitsh et al., [30]). Five other species may also occur in I Fraxinus i spp.: I A. convexicollis i , I A. beauprei i , I A. graminis i , I A. cyanescens i , and I A. roscidus i (Jendek & Poláková, [18]). [Extracted from the article]

The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an invasive woodboring pest of ash trees (Fraxinus sp.) in North America. Among the Asiatic parasitoids being released for the management of EAB in North America, Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) is the only EAB egg parasitoid. To date, more than 2.5 million O. agrili have been released in North America; however, few studies have examined its success as a biological control agent of EAB. We conducted studies to assess O. agrili establishment, persistence, spread, and EAB egg parasitism rates in Michigan at the earliest release sites (2007–2010), as well as at more recent release sites (2015–2016) in 3 Northeastern United States (Connecticut, Massachusetts, New York). In both regions, we documented successful O. agrili establishment at all but one release site. In Michigan, O. agrili has persisted at release sites for over a decade and spread to all control sites located 0.6–3.8 km from release sites. Overall, EAB egg parasitism ranged from 1.5% to 51.2% (mean of 21.4%) during 2016–2020 in Michigan and from 2.6% to 29.2% (mean of 16.1%) during 2018–2020 in the Northeastern states. Future research efforts should focus on factors affecting the spatiotemporal variation in EAB egg parasitism rates by O. agrili, as well as its potential range in North America. [ABSTRACT FROM AUTHOR]

Forest stands infested by emerald ash borer (EAB), Agrilus planipennis Fairmaire, experience extensive mortality of mature ash trees. Post-invasion woodlands commonly have a small contingent of mature lingering ash, an orphaned cohort of seedlings/saplings, and low EAB densities. To protect regenerating ash against rebounding EAB populations, a suite of biocontrol agents are being reared and released. USDA APHIS guidelines currently recommend the release of parasitoids into forests prior to overstory ash mortality at sites containing a variety of ash size classes and low to moderate but building EAB densities. To understand if biocontrol establishment and control of EAB is feasible in post-invasion sites, we assessed the establishment of parasitoids in 6 post-invasion forest stands in 2 regions of NY and compared EAB mortality in these stands to 2 regions where releases were conducted during the early-invasion phase. Results of parasitoid trapping indicates Tetrastichus planipennisi Yang established under both release strategies. Spathius galinae Belokobylskij & Strazanac was only released in post-invasion stands, where it was established successfully. Artificial EAB cohorts were established and life tables were constructed at 3 sites per region. EAB mortality due to T. planipennisi parasitism was similar under both release strategies 2 yr after release in post-invasion stands versus 8 yr after release in early-invasion stands. Combined mortality from T. planipennisi and woodpecker predation resulted in consistently low EAB reproductive rates. Future biocontrol releases could target forests identified as economically or ecologically important, regardless of whether EAB populations are increasing or have collapsed following initial invasion. [ABSTRACT FROM AUTHOR]

Biosurveillance monitors the prey of the solitary buprestid-hunting wasp, Cerceris fumipennis (Hymenoptera: Crabronidae), for the presence for emerald ash borer (Agrilus planipennis , Fairmaire: Coleoptera: Buprestidae). Still unresolved is the foraging range, and thus the surveillance range, of C. fumipennis. Foraging occurs in forest canopies and wasps are difficult to track. We assumed that the proportion of conifer-feeding beetles collected at a colony would be related to the proportion of conifers in the surrounding area. If this is the case, the radius of the area around a colony which best correlates the proportion of conifers with the proportion of conifer feeding prey should reflect the foraging range of the colony. In this study, we used 7 yr of foraging data, and the National Land Cover Dataset 2016 map to estimate the foraging range of C. fumipennis. Overall, we found that the highest correlation between prey type collected, and forest type present, was between 1,000 and 1,500 m from the nest sites. We thus conclude that surveillance of a colony of C. fumipennis will yield information about the presence of non-native buprestids within a 1.0–1.5 km radius. [ABSTRACT FROM AUTHOR]

Spathius galinae Belokobylskij (Hymenoptera: Braconidae) is among several parasitoids introduced as classical biocontrol agents for control of the invasive emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in the US. However, the successful establishment of this parasitoid and its efficacy in suppressing emerald ash borer vary among the release sites and regions. We hypothesize that forest microhabitats and parasitoid overwintering life stages affect parasitoid overwintering survival, development, and emergence phenology of adults in the spring. To test this, we placed logs containing 3 different larval stages of S. galinae (early instar larva, late instar larva, and cocoon) in ventilated jars in 2 distinct microhabitat sites, i.e., urban forest and mature natural forest. These were deployed in late fall of 2020 and remained in the field through winter. The emergence of adult parasitoids was recorded in spring through summer of 2021. Parasitoids in the warmer urban site emerged more quickly, emerging 12 d earlier than parasitoids in the cooler mature forest site. None of the S. galinae deployed as early instar larvae diapaused in either urban or forest sites. In both habitats, 27.1 to 32.1% of late instar larvae diapaused. Across overwintering larval stages, the median time of S. galinae emergence was about 24 d in the urban microhabitat, significantly shorter than that (36 d) observed in the mature forest microhabitat. Our findings suggest that environmental factors profoundly affect S. galinae phenology, and consequently emerald ash borer biological control. Spathius galinae Belokobylskij (Hymenoptera: Braconidae) se encuentra entre varios parasitoides introducidos como agentes de biocontrol clásico para el control del barrenador esmeralda del fresno invasivo, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), en los EE. UU. Sin embargo, el establecimiento exitoso de este parasitoide y su eficacia para suprimir el barrenador esmeralda del fresno varían entre los sitios y regiones de liberación. Nuestra hipótesis es que los microhábitats del bosque y los estadios de vida de hibernación del parasitoide afectan la sobrevivencia, el desarrollo y la fenología de emergencia de los adultos en la primavera. Para probar esto, colocamos troncos que contenían 3 estadios larvales diferentes de S. galinae (larva de estadio temprano, larva de estadio tardío y capullo) en frascos ventilados en dos sitios de microhábitat distintos, un bosque urbano y un bosque natural maduro. Estos se desplegaron a fines del otoño del 2020 y permanecieron en el campo durante el invierno. Se registró la aparición de parasitoides adultos desde la primavera hasta el verano del 2021. Los parasitoides en el sitio urbano más cálido emergieron más rápidamente, emergiendo 12 días antes que los parasitoides en el sitio de bosque maduro más frío. Ninguno de los S. galinae se desplegó como larvas de estadio temprano en diapausa en sitios urbanos o forestales. En ambos hábitats, entre el 27,1 y el 32,1% de las larvas de estadio tardío entraron en diapausa. A lo largo de los estadios larvales de hibernación, la media del tiempo de emergencia de S. galinae fue de aproximadamente 24 días en el microhábitat urbano, significativamente más corto que el (36 días) observado en el microhábitat de bosque maduro. Nuestros hallazgos sugieren que los factores ambientales afectan profundamente la fenología de S. galinae y, en consecuencia, el control biológico del barrenador esmeralda del fresno. [ABSTRACT FROM AUTHOR]

The emerald ash borer (EAB), Agrilus planipennis Fairmaire, is the most destructive invasive pest on ash (Fraxinus spp.) in the United States. We determined whether ash trees injected with emamectin benzoate (EB) could protect untreated neighboring ash trees. We also determined whether the selective treatment of ash trees with EB injections had adverse effects on the establishment of introduced larval parasitoids Tetrastichus planipennis Yang and Spathius galinae Belokobylskij & Strazenac. In experiment one, trees were treated with EB and then retreated 3 years later. Five years post initial treatment, we found that 90% of treated ash trees retained healthy crowns, significantly higher than those of untreated control ash trees (16%). For experiment two, trees only received one treatment of EB and after 2 years 100% of treated ash trees retained healthy crowns, significantly higher than those of untreated ash trees (50%). In both experiments, we found that distance from the central EB-treated tree was not a significant predictor for tree health or presence of EAB exit holes. Although distance from the EB-treated trees appeared to have a significant positive relationship with woodpecker feeding signs on neighboring trees, such relationships did not result in significant differences in the proportion of neighboring ash trees retaining healthy crowns between EB treatment and control plots. The introduced EAB parasitoids appeared to have established equally well between treatment and control plots. Findings are discussed in the context of integration of EB trunk injection with biological control for protection of North American ash against EAB. [ABSTRACT FROM AUTHOR]

Buprestids are an emerging threat to broadleaf forests across the world. Species such as emerald ash borer (EAB, Agrilus planipennis) seriously threaten ash (Fraxinus spp.) in North America and Europe. As it continues spreading west from European Russia, native European ash populations will suffer dramatic losses. Due to their cryptic lifestyle of the egg and larval stages on developing bark and vascular tissue, buprestids and other wood borers can be difficult to detect. Early detection tools are vital to implement fast eradication measures, and prevent the establishment of invasive species populations. Detection methods using polymerase chain reaction (PCR) assays to target specific taxa can be extremely timely to obtain results especially since samples need to be transported to the laboratory first. However, loop-mediated isothermal amplification (LAMP) eDNA assays are highly specific and sensitive providing results within 30 min after sample extraction. In this study, we investigated the specificity and sensitivity of an EAB LAMP assay as an early detection tool in Europe. The assay was specific to EAB when tested against 12 European Agrilus spp., five buprestids, two Scolytinae, and five cerambycids (n = 24). The LAMP assay sensitivity amplified DNA from a concentration as low as 0.02 pg/µL. These results demonstrate that the LAMP assay is a highly specific, sensitive tool that can be used to detect and monitor EAB in European forests and urban settings. [ABSTRACT FROM AUTHOR]

• Tetrastichus planipennisi and Spathius galinae parasitised Agrilus biguttatus larvae in no-choice laboratory assays. • Oobius agrili parasitised Agrilus biguttatus and A. convexicollis eggs in no-choice laboratory assays. • This study is the first to show parasitism of a non-target Agrilus species by Tetrastichus planipennisi. The emerald ash borer (EAB, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is devastating ash trees in its invaded range of North America and spreading rapidly towards Western Europe from European Russia and Ukraine. To allow a rapid response when the beetle is detected, slow its spread and protect trees as part of a wider integrated pest management programme, pre-emptive biological control strategies that are suitable for Great Britain and the rest of Europe must urgently be developed. Three classical hymenopteran biological control agents have been mass-reared and released within North America to control EAB: the egg parasitoid Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae), and the larval parasitoids Tetrastichus planipennisi and Spathius galinae Belokobylskij & Strazanac (Hymenoptera: Braconidae). This study presents data on the risk these parasitoid wasps might pose to British Agrilus beetles. "No-choice" laboratory assays tested the susceptibility of A. biguttatus Fabricus eggs and larvae and A. sulcicollis Lacordaire and A. convexicollis Redtenbacher eggs to the parasitoids. Oobius agrili, T. planipennisi and S. galinae all attacked A. biguttatus, and offspring were produced. Oobius agrili also attacked the eggs of A. convexicollis, but not A. sulcicollis. This study is the first to show parasitism of a non-target species by T. planipennisi. Further work is needed to fully assess the non-target risk of these parasitoids for release using more ecologically relevant tests, such as 'choice', semi-field and chemical ecology assays on the attacked Agrilus species. [ABSTRACT FROM AUTHOR]

• The emerald ash borer (EAB) Agrilus planipennis is spreading to Europe from Russia. • Biological control offers sustainable solutions to control invasive pests. • In Europe, parasitoids of species of the genus Agrilus may adopt EAB. • We conducted a literature review of European parasitoids of Agrilus spp. • Sixty-four parasitoid species attacking Agrilus spp. were recorded. The emerald ash borer (EAB), Agrilus planipennis , is a woodboring beetle native to East Asia. It is highly invasive in North America, where it causes large-scale dieback of American ash species, Fraxinus spp. EAB is also invasive in Western Russia and Ukraine, and it continues to spread towards Central and Western Europe where all three native ash species are susceptible. Biological control approaches offer sustainable solutions to control invasive pests. In North America, four Asian parasitoid species that have coevolved with EAB have been introduced to control the pest. In Europe, many species of the genus Agrilus occur, and it is likely that at least some of their parasitoids will adopt EAB as a host as it spreads across the continent. However, parasitoids of Agrilus spp., are very poorly known in Europe because of the difficulty of studying the parasitoid complex of these solitary wood boring insects. In this review, we provide a literature overview of studies and records of European parasitoids of Agrilus spp. to provide a basis for future studies on the emerging parasitoid complex of EAB in Europe. Parasitoid records were found for 24 European species of Agrilus. Sixty-four parasitoid species were recorded, mostly larval parasitoids. However, it is likely that several of them are erroneous host-parasitoid associations or misidentifications, and the biology of most species and their role in the population dynamics of their hosts has been poorly studied. It is recommended to conduct pre-emptive studies on these parasitoids and their suitability as potential biological control organisms with EAB. [ABSTRACT FROM AUTHOR]

Survival of North American species of ash (Oleaceae: Fraxinus spp. L.) is threatened by emerald ash borer (EAB), Agrilus planipennis (Fairmaire), a phloem-feeding beetle that destroys the vascular system of its host. In forested sites where ash is a dominant overstory species, mortality caused by EAB can substantially alter conditions, with potentially cascading effects on ecosystems. In urban forests, ash trees were often abundant and provided an array of ecosystem services because of their rapid growth, capacity to withstand stressful urban conditions and prior to EAB, low pest load. Annualized costs of managing EAB on urban ash trees over the next 30 yr in the United States has been estimated to approach $1.8 billion. Numerous cost-benefit analyses have demonstrated that it is more cost effective to retain mature ash trees with systemic insecticides than to replace these trees in urban areas. Effective protection of urban ash trees depends on deployment of systemic insecticides before EAB injury disrupts the vascular system that transports insecticide to the canopy. Given the ongoing spread of EAB, timely management is critical for protecting urban ash canopies. Over the last 2 decades, we have encountered persistent myths that have hindered the adoption of protective measures to preserve urban ash in communities recently infested by EAB. Here we review these myths and counter them with research-based evidence that supports and justifies an ash management program. Finally, we use the 5 basic tenets of IPM to outline an approach for managing EAB in urban forests. [ABSTRACT FROM AUTHOR]

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has killed millions of ash (Fraxinus spp.) trees across North America. Classical biological control using introductions of parasitoid wasps may provide a sustainable approach to managing this invasive insect. However, the establishment of parasitoids in the southern United States has been difficult. The phenology of emerald ash borer was studied in central North Carolina to inform biological control efforts that better align with the seasonal availability of susceptible emerald ash borer life stages in the warm climate of this region. Biweekly emerald ash borer life stage assessments were conducted in stands of infested green ash (Fraxinus pennsylvanica Marshall, Lamiales: Oleaceae) over 26 consecutive months (June 2019 through August 2021). Adult trapping was also conducted in these stands in the spring and summer of 2019, 2020, and 2021. Based on these collections, emerald ash borer exhibits a univoltine (1-yr) life cycle. Parasitoid-susceptible larvae (third and fourth instars in galleries) are present from late June through October (∼1,100–3,000 degree days base 10°C) and are mostly absent during the remainder of the year. Parasitoid release timings and the life history of selected parasitoid species should be aligned with this window of host availability to be effective. This characterization of emerald ash borer phenology and voltinism will help improve the timing and effectiveness of management efforts as this forest pest continues to spread in southern North America. [ABSTRACT FROM AUTHOR]

Despite a robust biocontrol program against emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), parasitoid populations cannot build quickly enough to save mature ash trees. The future of ash as a viable component of North American forests depends on survival of immature ash that were too small to be attacked during the initial outbreak. This study was designed to quantify impacts of established introduced parasitoids and native woodpeckers on the population growth of emerald ash borer infesting regenerating ash saplings in white ash forests. Most emerald ash borer larvae were killed by Tetrastichus planipennisi Yang and woodpeckers in the fourth instar. Life-table analyses revealed that the estimated net reproductive rate of emerald ash borer was R 0 = 4.2 in eastern New York and R 0 = 0.0 in western New York. Without mortality from parasitoids and woodpeckers, R 0 values would have been 16.4 and 7.9 in eastern and western New York, respectively. We monitored the health of mature and sapling ash trees from 2012 to 2017 and found that large trees were significantly more likely to be infested with emerald ash borer and to die than smaller trees. Fifty-four percent to 81% of ash saplings contained no living emerald ash borer, and the density of emerald ash borer at all sites was very low (< 4/m2). This study adds to the growing body of evidence that emerald ash borer biocontrol is contributing to population control and can help promote survival of young ash trees as forests recover from emerald ash borer outbreaks. [ABSTRACT FROM AUTHOR]

Simple Summary: Trunk-boring insects belong to one of the most destructive forest pests. Larvae in some groups are particularly difficult to detect since they make their living in trunks and no obvious sign can be found from outside. To deal with this problem, a new method is presented here, which is the embedding of a vibration probe into the tree trunk to pick up vibrations caused by larvae and the use of a model to distinguish whether the tree is infected. However, this procedure can experience severe interference from environmental noise, which is simultaneously picked up with vibrations. Thus, it is necessary to add a noise suppression process before discrimination. Previous examples have proved that the application of the analysis intended for sounds to boring vibrations is feasible. Therefore, we took advantage of deep learning-based speech enhancement and further improved it to develop a boring vibration enhancement model. The training data used in this research contains boring vibrations recorded within pieces of trunks and noise, which are common for trees' living environment. The experimental results indicate that the enhancement procedure provided by our model substantially increases the accuracy of several well-known classification models, guaranteeing a more practical larvae detection. The larvae of some trunk-boring beetles barely leave traces on the outside of trunks when feeding within, rendering the detection of them rather difficult. One approach to solving this problem involves the use of a probe to pick up boring vibrations inside the trunk and distinguish larvae activity according to the vibrations. Clean boring vibration signals without noise are critical for accurate judgement. Unfortunately, these environments are filled with natural or artificial noise. To address this issue, we constructed a boring vibration enhancement model named VibDenoiser, which makes a significant contribution to this rarely studied domain. This model is built using the technology of deep learning-based speech enhancement. It consists of convolutional encoder and decoder layers with skip connections, and two layers of SRU++ for sequence modeling. The dataset constructed for study is made up of boring vibrations of Agrilus planipennis Fairmaire, 1888 (Coleoptera: Buprestidae) and environmental noise. Our VibDenoiser achieves an improvement of 18.57 in SNR, and it runs in real-time on a laptop CPU. The accuracy of the four classification models increased by a large margin using vibration clips enhanced by our model. The results demonstrate the great enhancement performance of our model, and the contribution of our work to better boring vibration detection. [ABSTRACT FROM AUTHOR]

Agrilus planipennis (Coleoptera: Buprestidae) is the most serious invasive pest of ash trees (Fraxinus spp., Oleaceae) in the world. It has not yet reached the range of olive tree plantations, however it has been shown to complete its life cycle in this host tree. This pest native to East Asia was first found in Europe in Moscow in 2003 and has been spreading ever since. The aims of this study were to determine if the southern border of the range has already reached the Caucasus and to assess the potential range in this region based on host availability and heat availability. In 2021, we surveyed ash trees south to the known range in Russia. We did not find the pest in six cities in the North Caucasus region but found it in the city of Azov close to the Caucasus. Analysis of information about 550 localities of ash trees in the Caucasus showed that Fraxinus spp. is common throughout the region. The calculation of annual growing degree days base 10 °C indicated that the places where Fraxinus spp. grow above 1500 m are too cold for A. planipennis and therefore could potentially become a refuge for ash trees. The spread of A. planipennis to the Caucasus is of concern. First, the forest ecosystems of this region are endangered, since European ash Fraxinus excelsior is much more common there than in the currently infested regions in Russia. Second, the Russian Caucasus can become the gateway to Georgia, Armenia, Azerbaijan, Turkey and other countries of the Middle East and Southern Europe. We propose using Fraxinus angustifolia, F. ornus and Olea europaea growing in the Caucasus and adjacent regions as sentinel trees for the monitoring and pest risk assessment of these tree species. [ABSTRACT FROM AUTHOR]

Emerald ash borer (Agrilus planipennis Fairmaire (Coleoptera: Buprestidae)), an invasive phloem-feeding beetle native to Asia, has devastated North American ash forests since its detection in Michigan, United States in 2002. As the emerald ash borer has continued to spread, the potential for successful long-term management hinges upon the release, establishment, and spread of introduced larval and egg parasitoids for biological control. Here, we focus on the establishment and evidence for spatial spread of introduced larval parasitoid, Spathius agrili Yang and Spathius galinae Belokobylskij & Strazanac (Hymenoptera: Braconidae) in the state of Maryland. To assess each species, we analyzed historical release and recovery data and resampled previous release sites and nonrelease sites for establishment. We found little evidence of establishment or spread for S. agrili, despite a comparatively large number of release locations, events, and individuals. By contrast, despite much lower propagule pressure and shorter history of releases, we detected multiple established populations of S. galinae at release sites and at sites up to 90 km from the nearest release point approximately 3 yr after its most current release. Our findings show that S. galinae has established and spread rapidly following field releases whereas its congener, S. agrili has not. Although it may still be too early to evaluate the level of population control and ash protection afforded by S. galinae, these findings indicate the need for continued investment in S. galinae for emerald ash borer classical biological control efforts. [ABSTRACT FROM AUTHOR]

The invasive woodboring beetle emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) first was detected in the US in 2002 near Detroit, Michigan, USA. Since then it has continued to expand its range into the southern and midwestern sections of the country. Emerald ash borer was discovered in North Carolina, USA, in 2013, and is currently reported from more than 60 counties in the state. The present study was undertaken to begin determining the phenology of emerald ash borer in its newly expanded range below 40 °N latitude in North America. Here we report 4 yr of data on the overwintering stages of emerald ash borer in north-central North Carolina, obtained by debarking infested trees harvested from a single site near the northern border with Virginia, USA, with 1-yr additional data from a site about 39 km away. Results indicated that most emerald ash borers overwinter as fourth instars, with a small proportion advancing to the J-larva stage. Parasitoids that emerged from cocoons collected from emerald ash borer galleries and from logs held in emergence cages also were identified. These Hymenoptera include specimens of Xorides (Exomus) humeralis (Say) (Ichneumonidae), Atanycolus cf. cappaerti Marsh and Strazanac (Braconidae), Balcha indica (Mani & Kau) (Eupelmidae), Spathius sp. Nees (Braconidae), and Wroughtonia sp. Cameron (Braconidae). [ABSTRACT FROM AUTHOR]

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]

The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), native to Northeast Asia, is the most destructive invasive ash (Fraxinus spp.) pest in the United States. In the present study, we evaluated the effect of exposure of diapausing mature fourth instars (J-shaped larvae, JL) of EAB to cool temperatures, either 1.7 or 12.8°C for 1–9 mo, on their post-chill development including adult emergence, longevity, and lifetime fecundity under standard rearing conditions (26 ± 0.5°C, 16:8 h L:D). In addition, we determined the effect of different stages of the larvae chilled at 12.8°C for 3 mo on the subsequent post-chill development to EAB adults. Findings from the study revealed that a period (≥2 mo) of chill at 12.8°C is required for the termination of the EAB diapause. However, chill treatment of the larvae at the near zero temperature (1.7°C) does not result in the post-diapause larval development to adults, regardless of the chill time (1–9 mo). In addition, our results showed that chill treatment of immature young larvae (L1–L4 prior to JL) results in little production of EAB adults, indicating that EAB diapause predominantly as JL. Findings of this study may be useful to laboratory rearing of EAB from eggs through continuous generations and help us understand the pest's voltinism resulting from the diapause and post-diapause development under different climatic conditions. [ABSTRACT FROM AUTHOR]

The FraxiProtec, an autodissemination device loaded with the fungus Beauveria bassiana isolate CFL-A, was tested in the field to evaluate its potential to infect emerald ash borer adults and reduce their populations. During the 2-yr experimental period, the dispersion of B. bassiana -infected adults was also documented to assess the dissemination capacity of the biocontrol agent beyond the treated areas. The mean percentage of infected emerald ash borer in 2017 and 2018 in 15 treated sites was 43.3 ± 2.9% and 39.7 ± 3.9%, respectively, and no significant variation was observed over the tested years. Furthermore, a 40% significant reduction of the mean emerald ash borer population growth per tree in treated sites was recorded when compared to the control sites. Emerald ash borer infected with B. bassiana isolate CFL-A were collected from baited sticky traps in the sentinel stations in the area surrounding the FraxiProtec-treated sites. Even at a distance of 125 m, an average of 9.4 ± 2.6% infected emerald ash borer were collected. Finally, exploratory analyzes were carried out on parameters such as the area to be treated, ash tree density, and FraxiProtec density to document potential relationships, which could be used in the determination of a prescription. [ABSTRACT FROM AUTHOR]

Many jewel beetles (Coleoptera: Buprestidae) play an important ecological role in wood decomposition and nutrient cycling. Compared with other saproxylic species, buprestids are considered cryptic as they are difficult to sample and identify. As a result, factors that influence buprestid diversity and distribution are poorly understood. This is especially true in urban forests, which may be uniquely fragmented and contain unique species distributions. We utilized the native ground nesting hunting wasp Cerceris fumipennis Say to survey buprestids at 20 urban sites in Minnesota. We collected a total of 1,939 beetles consisting of 11 genera and 51 species, including 9 new state records for the state of Minnesota. We found a positive relationship between wasp size and size of beetle prey captured. Agrilus was the most common genus collected, followed by Dicerca. Species richness tended to decrease in sites with many emerald ash borers, Agrilus planipennis Fairmaire, which may reflect a potential tendency of wasps to return preferentially to high-density infestations of emerald ash borers. We found buprestid species richness positively correlated with site-level variables such as the number of dead trees within a 200 m radius around each C. fumipennis nesting site. Our work illustrates how C. fumipennis can be utilized for general buprestid surveys in urban areas to better understand the distribution of this cryptic family. [ABSTRACT FROM AUTHOR]

Cerceris fumipennis (Hymenoptera, Crabronidae) is a ground-dwelling wasp species that provisions its nests with wood-boring jewel beetles (Buprestidae), making it a useful tool for biosurveillance of buprestid forest pests, particularly the Emerald Ash Borer (Agrilus planipennis). The maximum foraging range of C. fumipennis has not yet been determined, but there have been limited studies on how far these wasps may fly when released from measured distances – an indication of their potential homing range. Careless (2008) determined the maximum homing range to be 2 km and hypothesized that the foraging range was limited to this distance. This study was coarsely-grained in that the wasps were released only at 1 km increments up to 3 km. Our study is finer-grained due to the release of wasps at intermediate distances within 3 km from the nesting area. Over 50% of the individuals released from 2.5 km and 3 km returned, indicating that the homing range of C. fumipennis is larger than previously estimated. The implications of this larger homing range and its effects on current predictions of foraging range are discussed. [ABSTRACT FROM AUTHOR]

The emerald ash borer (EAB), Agrilus planipennis (Fairmaire), is the most destructive invasive insect species of ash (Fraxinus spp.) in North America. An accurate method for early detection of this noxious insect pest is indispensable to providing adequate warning of A. planipennis infestation. A loop-mediated isothermal amplification (LAMP) assay (EAB-LAMP) was developed based on mitochondrial cytochrome c oxidase subunit I (COI) gene. The EAB-LAMP required only 30 min at 65°C to amplify A. planipennis DNA from specimens collected from geographically distinct locations. There was no cross-reactivity with other Agrilus and insect species. The developed EAB-LAMP differentially detected traces of A. planipennis genome (COI) within frass from various Fraxinus species. EAB-LAMP was also able to distinguish among A. planipennis DNA and other Agrilus species and nontarget insect species in trap captures. By detecting A. planipennis DNA in two additional trap captures (in situ), the EAB-LAMP was more sensitive and reliable than visual inspection. We tested the quantitative nature of the assay by evaluating pooled trap samples and demonstrated that the EAB-LAMP was capable of functioning optimally using a pool size of at least five individual trap samples. This potentially circumvents the need to perform large-scale individual analysis for processing trap samples. Considering its performance, specificity, sensitivity, and repeatability, the developed EAB-LAMP could be a valuable tool to support strategy and operation of large-scale surveillance for A. planipennis and could profitably be used in routine monitoring programs for effective management of A. planipennis. [ABSTRACT FROM AUTHOR]

Understanding the dispersal ability of invasive insects provides useful insights for developing effective management strategies. Historically, methods for marking insects for dispersal studies have been expensive, time‐consuming, labor‐intensive, and oftentimes ineffective, especially for woodboring beetles. Also, capturing or rearing insects requires human handling, which can alter behavior. Protein immunomarking is a well‐established technique for studying the dispersal of insects; however, it has not been applied to woodborers. This study evaluates the potential for using protein immunomarkers applied directly to woodborer‐infested trees to mark emerging beetles. Specifically, in the first experiment, we sprayed varying concentrations of ovalbumin (egg white) solution directly onto logs infested with emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae, Agrilini). In turn, an enzyme‐linked immunosorbent assay was used to detect the presence of protein on emerged beetles. To test the persistence of the mark, we applied varying concentrations of albumin to freeze‐killed beetles, mounted them on pins, and placed them over various time intervals in an exposed location outdoors. Adult EAB self‐marked as they emerged from protein‐treated trees, with higher protein concentrations persisting for longer on the cuticle. This technique offers a convenient, inexpensive, and durable means of marking woodborers and circumvents the need for human handling, allowing for more natural behavior and more realistic estimates of dispersal. Protein self‐marking may find application in studies of woodborer dispersal within natural forest environments. [ABSTRACT FROM AUTHOR]

Addressing the risk from pests present in wood and wood products destined for international trade is an essential step towards minimizing the movement, introduction and establishment of invasive species. One method of managing the pest risk associated with wood commodities is the use of a systems approach that incorporates multiple independent measures applied along a production pathway. However, quantifying the reduction of risk can be difficult because the approach requires raw material infested with the pest of interest at a sufficient density to be able to quantify changes in pest abundance. We tested a systems approach for the production of sawn wood using green ash, Fraxinus pennsylvanica Marshall (Lamiales: Oleaceae), infested with emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), by quantifying the change in pest density during the milling process and the precise effect of heat treatment on insects in situ. Greater than 90% of emerald ash borer were removed at the first step of the milling process (debarking) and >99% were removed before the production of green sawn wood. No insects survived kilning or heat treatment. All life stages of emerald ash borer were killed at 56°C and above. Heat, however, had no sublethal effect on emerald ash borer performance. These results show that the application of a systems approach to mitigate emerald ash borer in heat-treated, sawn wood is effective. Moreover, the model-system approach developed in this study can be a template for investigating the effect of systems approaches for other phloem-feeding insects. [ABSTRACT FROM AUTHOR]

Insect herbivores are more likely to successfully use a novel host if the plant is closely related to the ancestral host and the insect is polyphagous. Emerald ash borer (EAB), Agrilus planipennis (Fairmaire) (Coleoptera: Buprestidae) , is a specialist wood borer of ash (Fraxinus spp., Lamiales: Oleaceae) trees and one of the most destructive forest pests in North American forests. Recent studies have found that larvae can develop in stems of two ash relatives; white fringetree (Chionanthus virginicus (L.) [Laminales: Oleaceae]) and cultivated olive (Olea europaea (L.) [Laminales: Oleaceae]). For EAB adults, the ability to consume, successfully mate, and lay viable eggs on foliage of these hosts is unknown. Thus, we conducted two no-choice assays with adult EAB on foliage of white fringetree and olive paired with positive controls of susceptible ash. Larval performance was also examined in a reciprocal study with cut stems of white fringetree and green ash (Fraxinus pennsylvanica Marshall) to determine whether adult diet impacted the success of progeny. Longevity, consumption rates, and fecundity of adults were similar on white fringetree and ash foliage. In contrast, adults consuming olive died quickly, consumed more over time, and females laid far fewer eggs compared to those on ash. Adult diet did not impact larval success, but larvae in white fringetree stems grew slower. These results indicate that white fringetree is a suitable host for EAB to complete its lifecycle, although larvae perform more poorly on this host than in susceptible ash species. In contrast, the more distantly related olive appears to be a poor host for adult EAB, although some viable eggs were produced by females. [ABSTRACT FROM AUTHOR]

B Synonyms b : I A. fleischeri kurosawai i Obenberger, 1940; I A. tscherepanovi i Stepanov, 1954 (Jendek, [6]); I A. kochi i Théry, 1942; I A. fleischeri nipponicola i Kurosawa, 1963 (Jendek & Grebennikov, [7]); I A. fleischeri i var. I coreicus i Kurosawa, 1954 (Lee & Ahn, [8]; unavailable). Hosts I Agrilus fleischeri i infests poplars and willows as a cambial-feeding insect pest. I A. fleischeri i has been responsible for significant damage (tree mortality and decreased of wood quality) to economically important poplar trees in Liaoning, northeast China, and especially to I P. nigra i var. I italica i , which is widely found in the EPPO region (Zang I et al. i , [19]). Round wood and sawn wood of more than 6 mm thickness of I Populus i spp. and I Salix i spp. should either originate in pest-free areas or undergo debarking followed by heat treatment, irradiation or fumigation. [Extracted from the article]

There is an urgent need in Europe to prepare resources for the arrival of the emerald ash borer, Agrilus planipennis (Buprestidae, Coleoptera) from European Russia, and possibly other invasive jewel beetles. A lightweight, easy to handle, non‐sticky trap could facilitate monitoring and detection to derive information about emerald ash borer and other jewel beetle populations. In two experiments carried out over two consecutive years in an oak forest, a new non‐sticky multi‐funnel trap design with a light‐green (sometimes described as fluorescent yellow) visual cue was developed. Altogether, there were 238 (2018) and 194 (2019) specimens captured often (2018) and eight (2019) Agrilus species, eight of which are oak‐related and one (A. convexicollis) was linked to ash. The new light‐green multi‐funnel trap performed similarly to the sticky design with a similar coloured surface. Our results suggest that the new trap design may be suitable for catching a wide range of buprestid species. It may also have the potential to be further optimized with respect to visual and olfactory cues, which would provide an even more useful tool for monitoring both invasive and indigenous buprestids. [ABSTRACT FROM AUTHOR]

Most of the current understanding of the orientation and communication of jewel beetles arose from research on the Asian emerald ash borer (EAB), Agrilus planipennis , which has become one of the most destructive invasive forest insect pests in history following its introduction to North America and European Russia. From a European perspective, a number of jewel beetles have a high invasive risk similar to that of the emerald ash borer, including the potential threat of the bronze birch borer Agrilus anxius , the goldspotted oak borer Agrilus auroguttatus , and the twolined chestnut borer Agrilus bilineatus. Native jewel beetles expanding their geographic range include the cypress jewel beetle Ovalisia festiva and the black-banded oak borer Coraebus florentinus. Other native species are increasing in their importance, including the flathead oak borer Coraebus undatus , the two-spotted oak borer Agrilus biguttatus , the flatheaded beech borer Agrilus viridis and Agrilus cuprescens. Commonly used prism and multi-funnel trap designs and other promising experimental trap designs have been tested and compared in the US and in Europe. One factor considered has been colouration, typically purple and green. Another is olfactory attraction, both to plant volatiles and extracts such as (Z)-3-hexenol, Manuka oil, Phoebe oil and Cubeb oil, and also to pheromones such as (Z)-3-lactone, for emerald ash borer. Field observations have been made of mating and host-finding behaviours of oak buprestids based upon visual stimuli in North America and Europe. By using pinned dead EAB models, visual mating approaches have been observed by males of Agrilus biguttatus , Agrilus sulcicollis and Agrilus angustulus , which is a behaviour similar to that previously observed in EAB. Green plastic-covered branch-traps significantly out-performed other trap designs and caught more Agrilus jewel beetles if an artificial visual decoy that copies a beetle body was included. A higher fidelity decoy offered the same distinctive light-scattering pattern as real resting EAB females and elicited the full sequence of stereotypical male mating flight behaviour of EAB and A. biguttatus from up to 1 m away. An optimization of visual, olfactory and other possible stimuli has likely not yet been achieved. More sophisticated trap designs could lead to more sensitive detection capabilities with increased selectivity. [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]

Concern about the potential for the bronze birch borer, Agrilus anxius , (BBB) to invade Europe and decimate European Birch trees motivated exploration of tools developed for the emerald ash borer, Agrilus planipennis (EAB) for the detection and monitoring of BBB. Both purple prism traps and green multi-funnel traps were hung in girdled and non-girdled birch trees and ash trees. Beetles were overwhelmingly caught in traps hung in their own host trees. Girdling increased the number BBB, but not EAB, caught in traps. Neither EAB nor BBB showed a preference between trap types. Traps hung in second-year girdled birch trees captured as many BBB per trap as first-year girdled birch trees, and were more effective as detectors than first-year girdled trees. Other native buprestids were caught in traps. Chrysobothris species strongly preferred purple prism traps and Anthaxia species preferred green multi-funnel traps. Non-target Agrilus varied in preference. Native ash borer A. subcinctus , strongly preferred green multi-funnel traps hung in ash trees. Agrilus bilineatus , the two-lined chestnut borer, preferred purple prism traps. Traps hung in girdled birch trees show strong promise as a monitoring and detection tool for BBB. [ABSTRACT FROM AUTHOR]

Biological control offers a long-term and sustainable option for controlling the destructive forest pest emerald ash borer (EAB), Agrilus planipennis Fairmaire, in North America. Three larval parasitoids, Spathius agrili Yang (Hymenoptera: Braconidae), Tetrastichus planipennisi Yang (Eulophidae), and Spathius galinae Belokobylskij & Strazanac, have been introduced to North America from the native range of EAB (northeastern Asia). While T. planipennisi appears to be persisting where it has been introduced in northern United States, S. agrili failed to establish in northeastern states. The more recently identified parasitoid S. galinae was recovered from the Russian Far East and climate matching suggests it should be suited for release in colder climates. We collected data on the phenology of EAB and its introduced larval parasitoids from colonies established in an insectary, growth chambers, and field-caged trees in Syracuse, New York to determine whether asynchrony between parasitoids and EAB or climate could impact establishment and persistence. Phenological data indicated EAB has one and 2-yr life cycles in New York, with parasitoid-susceptible EAB larvae available spring to fall for parasitism. Insectary and growth chamber studies indicated S. galinae and T. planipennisi were synchronous with EAB phenology, and field studies suggested both species could overwinter in northeastern climates. Spathius agrili was asynchronous with EAB phenology and climate, emerging when fewer parasitoid-susceptible EAB larvae were available and temperatures were not optimal for survival. Our results suggest S. galinae and T. planipennisi are suited for biological control of EAB at the northern limits of its range in North America. [ABSTRACT FROM AUTHOR]

Emerald ash borer (EAB, Agrilus planipennis Fairmaire [Coleoptera: Buprestidae]) is a wood boring beetle that is an invasive pest of ash trees (Fraxinus spp.) in North America. In 2014, it was reported that EAB had infested white fringetree (Chionanthus virginicus L. [Lamiales: Oleaceae]) in Ohio and was since found to have infested this species across its invasive range. In 2018, we reexamined 166 white fringetrees in Illinois, Indiana, Ohio, and Pennsylvania that had been previously examined for EAB attack in 2015 to determine their fate. We assessed tree health and EAB infestation in each tree, assigned an infestation status of newly, continuously, not reinfested, or never infested, and compared the trees' current status to their 2015 status. This assessment was done to determine whether their health and infestation status had changed through the EAB invasion wave. We found that attack rates declined: 26% of trees were infested in 2015 whereas only 13% were in 2018, likely coinciding with declining beetle populations in the area. Overall tree health improved for trees that were not reinfested by EAB after a record of attack in 2015, suggesting that they can survive and recover from EAB attack. Conversely, health declined for newly and continuously infested trees, indicating that they became stressed from EAB attack. Although the majority of the trees survived the invasion wave, several were removed from various sites due to EAB attack suggesting that white fringetree varies in its resistance and tolerance to attack. As beetle populations continue to expand geographically, infestation rates will likely increase and health of white fringetrees will decrease with the EAB attack wave, especially as EAB reaches denser populations of fringetrees. [ABSTRACT FROM AUTHOR]

Both Spathius agrili Yang and Spathius galinae Belokobylskij and Strazanac are host-specific parasitic wasps introduced for biological control of emerald ash borer in North America. Spathius agrili is native to northeastern China and S. galinae comes from a more northern, colder climate in the Russian Far East. Their origin may lead to differing abilities to adapt to climate and their host in North America. We conducted both field and laboratory experiments to determine the timing of early season emergence and synchronization of each parasitoid species to their host in the United States, and if manipulating prerelease conditions could affect emergence time. A cold acclimatization treatment prior to parasitoid emergence was assessed and compared with untreated control group reared with standard rearing protocols. Stands of naturally emerald ash borer-infested ash were sampled at two locations in Virginia throughout the experiment to determine when the parasitoid-susceptible life stage (third to fourth instar) occurred. Untreated S. galinae emerged approximately 2 wk earlier than any other cohort, whereas cold acclimatized S. galinae emerged later than any other cohort. Emergence time of S. agrili was unaffected by cold acclimatization. Cold acclimatization treatment did not affect the parasitism rate of either species, nor did it have multigenerational effects. Emergence time of the subsequent generation of S. agrili was delayed by cold acclimatization treatment, whereas S. galinae experienced no multigenerational effects. At Virginia field sites, susceptible EAB larvae were present during the emergence time of all four groups of parasitoids. Untreated S. galinae had the least overlap with any susceptible EAB larvae. [ABSTRACT FROM AUTHOR]

Novel hosts lacking a coevolutionary history with herbivores can often support improved larval performance over historic hosts; e.g., emerald ash borer [ Agrilus planipennis (Fairmaire) Coleoptera: Buprestidae] on North American ash (Fraxinus spp.) trees. Whether trees are novel or ancestral, stress on plants increases emerald ash borer preference and performance. White fringetree [ Chionanthus virginicus (L.) Lamiales: Oleaceae] and olive [ Olea europaea (L.) Lamiales: Oleaceae] are closely related non-ash hosts that support development of emerald ash borer to adulthood, but their relative suitability as hosts and the impact of plant stress on larval success has not been well studied. In a series of experiments, survival and growth of emerald ash borer larvae on these novel hosts were examined along with the impact of stress. In the first experiment, larvae grew more slowly in cut stems of olive than in green ash [ Fraxinus pennsylvanica (Marshall) Lamiales: Oleaceae] and several adults successfully emerged from larger olive stems. In two experiments on young potted olive with photosynthesizing bark, larvae died within a week, but mechanical girdling increased the rate of gallery establishment. The final two experiments on field-grown fringetrees found increased larval survivorship and growth in previously emerald ash borer attacked and mechanically girdled plants than in healthy stems or stems treated with the defense hormone, methyl jasmonate. Our results demonstrate that these non-ash hosts are less suitable for emerald ash borer than preferred ash hosts, but previous emerald ash borer attack or girdling led to better survival and growth demonstrating the importance of stress for larval success. In potted olive, high mortality could be due to higher loads of toxic compounds or the presence of chlorophyllous tissue. [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]

The emerald ash borer (EAB) Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive woodboring beetle native to northeastern Asia that continues to expand its range within North America and European Russia. The insect reproduces within and kills most North American species of ash Fraxinus spp.Because both the adult and larval life stages of EAB are difficult to detect prior to development of tree symptoms, much work has focused on quantifying spread and clarifying the potential movement pathways to improve early detection and monitoring strategies.In the present study, we retrospectively analyzed county‐level infestations of emerald ash borer in the state of Iowa, U.S.A., subsequent to the initial detection of EAB in 2010. Visual data analysis had suggested that new infestations were not in accordance with the expected patterns of establishment along roads, near campgrounds or by large population centres.We found a positive correlation between the establishment and detection of EAB in Iowa counties and the length of railroads in each county. To our knowledge, this is the first statistically significant association between rail pathways and the spread of EAB on the North American continent. [ABSTRACT FROM AUTHOR]

Emerald ash borer Agrilus planipennis (Coleoptera: Buprestidae) is one of 20 priority quarantine pests of the European Union. It is native to Asia and is established in the USA, Canada, European Russia, and Ukraine. We made the first prognosis of the potential range of A. planipennis in Europe based on heat availability. Mean annual growing degree days base 10 °C (AGDD10) was calculated for each grid square (0.25° × 0.25° latitude x longitude degrees) on the Earth’s surface. Minimal AGDD10 recorded in the grid squares currently occupied by A. planipennis was 714° in Asia, 705° in North America, and 711° in European Russia. Agrilus planipennis has never been recorded in localities with AGDD10 below 700°. If the phenotypic plasticity would not allow this species to overcome this threshold, cold regions of Europe would probably not be invaded by A. planipennis. Thus, Fraxinus excelsior could potentially escape from A. planipennis in some regions of Norway, Sweden, Finland, Ireland, and Great Britain.

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), quickly established itself as an invasive species in North America after it was first detected near Detroit, Michigan, USA, in 2002. Just 1 yr later, emerald ash borer was introduced accidentally into Maryland, USA, on imported ash nursery stock. After quarantine and eradication efforts failed, a classical biological control program was initiated in Maryland in 2009 with the release of 2 larval parasitoids: Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae), and 1 egg parasitoid, Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae). Timing is critical to the success, efficiency, and cost-effectiveness of classical biological control programs where release of parasitoids must coincide temporally with that of susceptible stages of the host. In 2017, periodic field surveys at 2 sites in central Maryland were conducted to assess emerald ash borer phenology using green funnel traps to sample adults, and debarking infested ash trees to sample larval stages. Adult emerald ash borer first appeared in traps on 18 May 2017 (479 growing degree d base 10 [GDD10]), peaked on 15 Jun (823 GDD10), and were absent from 13 Jul (1,301 GDD10) through 12 Oct (2,598 GDD10) when surveys were terminated. Larval sampling in early Aug (1,698 GDD10) found all larval instars present, the most common being the second instar (46%), followed by the third instar (28%), fourth instar (20%), first instar (5%), and prepupal J-shaped larvae (J-larva) (0.5%). J-larvae are so called because after excavating a pupal chamber, the head is bent down 180 degrees to the rest of the body, resembling the shape of the letter J. Larval sampling in late Oct (2,710 GDD10) found J-larvae to be the dominant stage present (92.2%), followed by fourth instar (4.8%), third instar (2.4%), and second instar (0.6%). We found that emerald ash borer was univoltine, and that nearly 50% of emerald ash borer larvae had developed to stages susceptible to parasitism (third and fourth instar) by early Aug (1,698 GDD10). By late Oct (2,710 GDD10), 92% had developed beyond parasitoid susceptible stages (J-larvae). These findings suggest that egg parasitoid releases are best targeted from early May to late Jun at an approximate GDD10 range of 300 and 1,100 with larval parasitoid releases best targeted between 1,400 and 2,500 GDD10. [ABSTRACT FROM AUTHOR]

The emerald ash borer (EAB) Agrilus planipennis (Fairmaire, Coleoptera: Buprestidae) will have untold impacts on the contributions hardwood timber products provide Louisiana's economy. We modeled a scenario where ash mortality was assumed to follow a PERT-Beta distribution to kill essentially all Louisiana ash within 25 yr. Future ash mortality volumes were discounted to the present and valued using market prices to estimate a present effect on timber receipts. Assuming the dead timber would have otherwise been typical trees of average quality, stumpage was presently valued at US$1.57 million, with deliveries totaling US$3.48 million. A salvage arrangement using the double declining balance method coupled with a second PERT-Beta distribution centered upon Louisiana's current 2.84% harvest-to-inventory proportion depreciated the timber's value monthly over 1 yr. Following salvage, average stumpage revenue declined −US$1.54 million, mill deliveries fell −US$3.41 million, whereas state timber severance tax collections declined by −US$46,800. The value added and employment direct effects to Louisiana's economy averaged −US$882,400 and −41.6 jobs, respectively. The multiplier effects of these losses emanating from the timber industry resulted in additional declines averaging −US$2.56 million in value added and −45.6 jobs across the state economy on the drop in output of −US$4.51 million. The total economic effects summed to −US$3.44 million in value added and −87.1 jobs on output declines of −US$9.46 million. [ABSTRACT FROM AUTHOR]

We studied the mating behavior and reproductive biology of three members of the genus Agrilus : the bronze birch borer, Agrilus anxius Gory; the twolined chestnut borer, Agrilus bilineatus (Weber); and the emerald ash borer, Agrilus planipennis Fairmaire. All three species share a highly stereotyped mating behavior. However, the copulation duration of A. planipennis was 90% longer than that of its two congeners. Female reproductive tracts of the three species were anatomically similar, as were the spermatophores. Within the spermatophores, sperm were single in A. anxius and A. bilineatus , while in A. planipennis , sperm were bundled in groups of approximately 20 in a hyaline sheath. We found that field-caught A. anxius and A. bilineatus had higher rates of female insemination than A. planipennis. In additional studies with A. planipennis and A. anxius , we found that mating duration was related to mating success, and fecundity for A. planipennis , but not for A. anxius. For both A. planipennis and A. anxius , the spermatophore was passed to the female toward the end of the copulatory period. Sperm were found in the spermatheca immediately after copulation ended in A. planipennis and 30 min after copulation ended in A. anxius. We present possible explanations for these differences. [ABSTRACT FROM AUTHOR]

Pests and disease have become an increasingly common issue as globalized trade brings non-native species into unfamiliar systems. Emerald ash borer (Agrilus planipennis), is an Asiatic species of boring beetle currently devastating the native population of ash (Fraxinus) trees in the northern forests of the United States, with 85 million trees having already succumbed across much of the Midwest. We have developed a reaction-diffusion partial differential equation model to predict the spread of emerald ash borer over a heterogeneous 2-D landscape, with the initial ash tree distribution given by data from the Forest Inventory and Analysis. As expected, the model predictions show that emerald ash borer consumes ash which causes the local ash population to decline, while emerald ash borer spreads outward to other areas. Once the local ash population begins to decline emerald ash borer also declines due to the loss of available habitat. Our model's strength lies with its focus on the county scale and its linkage between emerald ash borer population growth and ash density. This enables one to make accurate predictions regarding emerald ash borer spread which allows one to consider various methods of control as well as to accurately study the economic effects of emerald ash borer spread. [ABSTRACT FROM AUTHOR]

The emerald ash borer (EAB), Agrilus planipennis Fairmaire, a buprestid beetle native to Asia, has become a serious pest of ash trees (Fraxinus spp.) in North America since the early 2000s. Due to the impracticality of applying insecticides in natural forests, biocontrol is the most viable method to manage EAB in natural ecosystems. Here, we report the first evidence for the establishment and impact of Spathius galinae Belokobylskij & Strazenac, a larval parasitoid first released in North America in 2016 and 2017 at six mixed-hardwood forest sites, in Connecticut, New York, and Massachusetts. We also report current levels of abundance and parasitism of another introduced larval EAB parasitoid, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), released in 2015 and 2016 in these same sites. Spathius galinae was recovered at all release sites in 2018, and its density in sampled trees had increased 1.5- to 20-fold (relative to the first postrelease sample year), reaching a final density of 2.3–14.3 broods/m2 of phloem area and causing 13.1–49.2% marginal rate of parasitism at four of the six sites. In contrast, T. planipennisi was only recovered in 2018 at four of the six release sites, and both its density (0.1–2.3 broods/m2 of phloem area) and parasitism (0.1–5.6%) were lower than that of S. galinae throughout the study at the four sites where recoveries were made. Our data fill a critical gap in the development of a biocontrol-based EAB management plan to protect surviving ash trees capable of reaching maturity and producing replacement trees. [ABSTRACT FROM AUTHOR]