Agrilus Species Research Articles

A review of Agrilus cuprescens (Ménétries, 1832), the rose stem girdler, in North America

Abstract Agrilus cuprescens (Ménétries, 1832), the rose stem girdler, is a Palearctic Buprestidae (Coleoptera) pest of Rosa and Rubus species. Its introduction and consequent spread across North America may now make it the most widely distributed Agrilus species, globally. No evidence reviewed indicated A. cuprescens was present in North America long before it was first reported on Rosa in New Jersey, USA, in 1913. The species incrementally progressed westward, reaching the Pacific coast in Washington, USA, 101 years later. Future spread is most likely within the northern Canadian prairies and the Pacific Northwest regions. Its presence in the latter region poses a contemporary threat to epicentres of Rubus production in both the United States and Canada. As of 2022, confirmed spread within the region extended nearly to the Canadian border in Washington and the southern Willamette Valley in Oregon. The most comprehensive, foundational investigations of A. cuprescens in North America were conducted in the late 1930s and early 1940s in New York, USA, and in Utah, USA, during the late 1950s and early 1960s following damaging outbreaks on Rubus. Ongoing research in the Pacific Northwest is attempting to refine information on this pest as it progresses towards naturalization within a new North American ecological and agricultural context. This review aggregates and clarifies the geographical progression, biological understandings and management of this species in North America, which has been fraught with a convoluted history of misidentifications, and varying degrees of consideration given to it as a pest of concern.

Efficacy of trapping protocols for Agrilus jewel beetles: a multi-country assessment

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.

Enhancing Buprestidae monitoring in Europe: Trap catches increase with a fluorescent yellow colour but not with the presence of decoys.

This study investigated the efficacy of various traps differing in colour (green or yellow), presence or absence of decoys (dead Agrilus planipennis) or design (commercial MULTz or multifunnel traps, and homemade bottle- or fan-traps) for monitoring European Buprestidae in deciduous forests and pear orchards. Over two years, we collected 2220 samples on a two-week basis from 382 traps across 46 sites in Belgium and France. None of the traps proved effective for monitoring Agrilus sinuatus in infested pear orchards (17 specimens captured in 2021, 0 in 2022). The decoys did not affect the catch rates whatever the trap model, colour, buprestid species or sex. The fluorescent yellow traps (MULTz and yellow fan-traps) tended to be more attractive than the green traps (green fan-traps and, to a lower extent, multifunnel green traps). Most Agrilus species showed similar patterns in mean trap catches, with the exception of Agrilus biguttatus, which had the largest catches in the green multifunnel traps. Finally, we observed a high variation in catch rates between localities: the site explained 64% of the catches variance, while the tree within the site and the type of trap explained only 6-8.5% each. In many sites, we captured very few specimens, despite the abundance of dying mature trees favourable to the development of Buprestidae. For the early detection of non-native Buprestidae, it therefore seems essential to maximise the number of monitoring sites. Due to their cost-effectiveness, lightweight design, and modularity, fan-traps emerged as promising tools for buprestid monitoring. The study's findings extend beyond European fauna, as a preliminary trial in Canada suggested that yellow fan-traps could also improve captures of non-European buprestid species and catch species of interest such as Agrilus bilineatus (a species on the EPPO A2 list of pests/pathogens recommended for regulation in the EU).

The larval, pupal and mitogenomic characteristics of Agrilusadelphinus Kerremans, 1895 (Coleoptera, Buprestidae) from China.

In this study, the larva and pupa of Agrilusadelphinus are described and illustrated. DNA barcoding (COI gene) was used to associate the larval and pupal stages with adults based on the maximum-likelihood method. In the resulting phylogenetic tree, species from the same species-group were found to be clustered on a branch with high support value. To better understand A.adelphinus, the complete mitochondrial genome of this species was also sequenced and annotated. Comparing this genome to the known mitogenomes of Agrilus species, the newly sequenced genome is shorter, with 15,732 bp. However, its whole mitogenome composition and gene orientation were consistent with that of most species of Buprestidae. In the mitogenome of A.adelphinus, the ATGATAG sequence was observed between ATP8 and ATP6, which is ATGATAA in other insect mitogenomes. Leu2, Phe, Ile, Gly, and Ser2 were the five most frequently encoded amino acids. The results further prove that DNA barcoding can remove the limitation of traditional taxonomy which cannot identify to species all developmental stages. This study also provides valuable molecular and morphological data for species identification and phylogenetic analyses of the genus Agrilus.

Summary of native geographic distribution of all 3,341 species of the most speciose animal genus Agrilus (Coleoptera: Buprestidae)

We present a summary of the geographic distribution data of all 3,341 species of the jewel-beetle genus Agrilus taxonomically valid at the end of 2022. Our work is richly illustrated with maps and diagrams. The genus Agrilus is the most speciose in the Americas (1,292 species) and Asia (1,187 species). The Americas have the best-delimited fauna at the regional level, with 100% of Agrilus species unique to the region, followed by those of Africa (95.8%) and Asia (93.4%). Europe has the lowest percentage of unique Agrilus species on all levels (regional, subregional and country). Among the subregions, the genus Agrilus is the most speciose in South-Eastern Asia (784 species), South America (769), Central America (427) and Eastern Asia (342); on the other hand, Micronesia has a single species, Polynesia has six species and the Caribbean has 18 species. New Zealand has no Agrilus. Brazil (477 species), Mexico (317) and Laos (265) are the three countries with the highest number of Agrilus species. Among 3,341 Agrilus species, 2,924 (87.5%) are unique to one biogeographic realm or transitional zone, and 417 species (12.5%) are shared by two or more biogeographical realms or transitional zones. Three widely distributed Agrilus species found in four biogeographic realms or transitional zones (A. acutus, A. auriventris and A. occipitalis) are pests of cultivated plants Citrus, Abelmoschus, Corchorus, Hibiscus, Malachra, Urena, are likely native to Southeastern Asia and were dispersed by humans. The number of Agrilus species by biogeographic realm varies between 12 (Oceanic) and 1,115 (Neotropical). The genus Agrilus is most speciose in the following realms: Neotropical (1,115 species, 33.4%), Indomalayan (810, 24.2%) and Afrotropical (694, 20.8%). The percentage of unique Agrilus species by biogeographic realm or transitional zone varies between 15.2% (Nearctic–Neotropical transitional zone) to 95.7% (Afrotropical realm). The range of 2,803 Agrilus species (83.9%) lies within a single biogeographic realm: Neotropical (974 species), Afrotropical (665), Indomalayan (662), Palearctic (234) Australasian (174), Nearctic (86) and Oceanic (8). Agrilus species reported from the largest number of countries are A. viridis, A. cuprescens, A. pratensis, A. angustulus, A. biguttatus, A. subauratus, A. cyanescens, A. suvorovi, A. hyperici and A. graminis; they are all native to the Palearctic realm. French Guiana (1.81), Laos (1.12), Vietnam (0.54) and Malaysia (0.53) are the countries with the highest number of Agrilus species per thousand square kilometers. On the sub-country level, the Laotian provinces Houaphan (7.09) and Bolikhamxai (5.52), as well as the Thai province Mae Hong Son (6.55) have the highest number of Agrilus species per thousand square kilometers. Indochina, French Guiana and Mexico are the global hotspots of Agrilus diversity. Our estimates suggest that the true number of Agrilus species in subtropical and tropical zones is at least twice higher than is currently known.

The Hazel Stem Borer, Agrilus pseudocoryli (Coleoptera: Buprestidae), as a Pest of Hybrid Hazelnuts.

Nuts from hybrid hazels (Corylus americana Walter × Corylus avellana L.) are a burgeoning, novel industry for the Great Lakes region of the United States. As such, scant information exists about the pest complex, although stem-boring beetles in the genus Agrilus Curtis (Coleoptera: Buprestidae) have been noted by growers as potential pests. Here, we report results of a comprehensive survey of 186 plants in a hybrid hazel planting consisting of nine cultivars in southeastern Minnesota affected by stem borers. Sixteen percent of the hybrid hazel plants exhibited between 25 and 100% buprestid associated dieback. Morphological and molecular identification of the adult and larval buprestids colonizing hybrid hazel plants revealed that the hazel stem borer, Agrilus pseudocoryli Fisher, was the only species present. Adult A. pseudocoryli were observed on plants between 8 June and 13 July 2021. Plants with higher damage ratings from the hazel stem borer were more likely to exhibit signs of eastern filbert blight (Anisogramma anomala Peck), a fungal pathogen virulent to C. avellana. Some hazel cultivars were more susceptible to damage from stem borers than others. Taken together, our findings suggest that the hazel stem borer has the potential to impact hybrid hazelnut yield. We speculate that a regional drought may have promoted increased populations of the hazel stem borer, as native Agrilus species are often secondary pests that become problematic when environmental stresses decrease host resistance. More research is needed to elucidate interactions between hazels, buprestid pests, and environmental conditions to predict impacts on crop yields.

Mortality of Bark- and Wood-boring Beetles (Coleoptera: Buprestidae, Cerambycidae, and Curculionidae) in Naturally Infested Heat-treated Ash, Birch, Oak, and Pine Bolts.

Firewood and wood packaging material (WPM) are major pathways for moving bark- and wood-infesting insects (borers). Heat treatment regulations for interstate firewood movement vary among U.S. states: from 56°C for 30 min to 71.1°C for 75 min. Current WPM international standards (ISPM 15) require heating to a minimum of 56°C for 30 min throughout the profile of the wood. Using bolts from infested ash (Fraxinus), birch (Betula), oak (Quercus), and pine (Pinus) trees in Michigan, we assessed borer mortality at core temperatures of 50, 53, 56, and 60°C maintained for 30 min in chambers set to 60, 65, 70, or 75°C. After treatment, bolts were monitored for adult emergence and later dissected to determine borer mortality rates. Mortality was high to complete for all heat treatments and increased with both increasing core and chamber temperatures. For the Agrilus (Buprestidae) species tested, there was complete mortality of Agrilus anxius on birch and Agrilus planipennis on ash when core temperatures of 56°C or higher were targeted regardless of chamber temperature. However, on oak, a few Agrilus bilineatus and Agrilus sulcicollis survived in bolts heated to 56°C in chambers at 60 and 65°C, and some A. sulcicollis survived in chambers set at 70 and 75°C. Similarly, a few pine-infesting borers survived heating to 56°C at all chamber temperatures. However, there was complete mortality in all hosts when bolts were heated to 60°C for 30 min, regardless of chamber temperature. Results are discussed in terms of current treatment regulations for firewood and WPM.

Diversidad del género Agrilus Curtis (Coleoptera: Buprestidae) en América del Sur

Using an updated checklist of the Agrilus species of South America, it is analyzed the status of knowledge of the Agrilus fauna for each country on the continent. When the geographical extent of each country and the number of known species are considered, a great disparity of knowledge emerges, with some countries (e.g., French Guyana) being relatively well investigated and others (e.g., Ecuador, Peru, Colombia) for which the state of knowledge is still embryonic. It is therefore reasonable to expect the number of known species will increase greatly as further research is conducted, especially in the latter countries.

Development of a Loop-Mediated Isothermal Amplification Assay as an Early-Warning Tool for Detecting Emerald Ash Borer (Coleoptera: Buprestidae) Incursions.

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.

Developing a non‐sticky trap design for monitoring jewel beetles

AbstractThere 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.

Agrilus mali Matsumara (Coleoptera: Buprestidae), a new invasive pest of wild apple in western China: DNA barcoding and life cycle.

Agrilus mali Matsumara (Coleoptera: Buprestidae) is a wood‐boring beetle distributed to eastern China that occasionally injures apple species. However, this wood‐boring beetle is new to the wild apple forests (Malus sieversii) of the Tianshan Mountains (western China) and has caused extensive tree mortality. The development of a biological control program for these wild apple forests is a high priority that requires exploration of the life cycle, DNA barcoding and taxonomic status of A. mali. In this study, to determine the diversity of invasive beetles, a fragment of the mitochondrial cytochrome oxidase gene was analyzed. Based on the results, beetles from Gongliu and Xinyuan counties of Xinjiang were identical but differed from those in the apple nursery of Gongliu by a single‐nucleotide substitution. We summarize the taxonomic status, relationships, and genetic distances of A. mali among other Agrilus species using the Tajima‐Nei model in maximum likelihood phylogeny. Analysis revealed that A. mali was closely related to Agrilus mendax and both belong to the Sinuatiagrulus subgenus. The life cycle of A. mali was investigated based on a monthly regular inspection in the wild apple forests of Tianshan. Similar to congeneric species, hosts are injured by larvae of A. mali feeding on phloem tissue, resulting in serpentine galleries constructed between bark and xylem that prevent nutrient transport and leading to tree mortality. Future studies will focus on plant physiological responses to the invasive beetles and include surveys of natural enemies for a potential classical biological control program.

Field parasitism and host specificity of Oobius primorskyensis (Hymenoptera: Encyrtidae), an egg parasitoid of the emerald ash borer (Coleoptera: Buprestidae) in the Russian Far East

Oobius primorskyensis Yao and Duan (Hymenoptera: Encyrtidae) is a recently described egg parasitoid of the emerald ash borer (EAB), Agrilus planipennis Fairmaire, from the Russian Far East. To support the potential introduction of this new parasitoid for biocontrol of EAB in North America, we surveyed EAB eggs on infested green ash (Fraxinus pennsylvanica Marsh) trees in the Russian Far East and documented the rate of EAB egg parasitism by O. primorskyensis. After establishing quarantine colonies of O. primorskyensis in the United States, we tested the parasitoid against eggs of 30 taxa of insects, mostly native North American wood-boring beetles in the families Buprestidae and Cerambycidae plus one unidentified weevil, one predatory coccinellid, one pentatomid and one moth. Field observations showed that EAB egg parasitism rate ranged from 23 to 44% in the Russian Far East and O. primorskyensis was the only egg parasitoid recovered from the parasitized eggs collected there. Quarantine testing showed that O. primorskyensis attacked seven out of nine Agrilus species, but not any of the other non-target species tested. Percentage parasitism of A. anxius (40%) and A. cephalicus (30%) was comparable to parasitism of their corresponding EAB (positive) control (29–30%). However, percentage parasitism of the other five attacked species (A. bilineatus, A. egenus, A. fallax, A. macer, and A. oblongus) were significantly less (4–17%) than for the EAB control (60–90%). These results indicate that the host specificity of O. primorskyensis may be limited to species phylogenetically closely related to EAB, such as those in the genus Agrilus. Additional testing is needed to determine whether the eggs of other buprestid genera are utilized by the species as well.

First molecular phylogeny of Agrilus (Coleoptera: Buprestidae), the largest genus on Earth, with DNA barcode database for forestry pest diagnostics.

All more than 3000 species of Agrilus beetles are phytophagous and some cause economically significant damage to trees and shrubs. Facilitated by international trade, Agrilus species regularly invade new countries and continents. This necessitates a rapid identification of Agrilus species, as the first step for subsequent protective measures. This study provides the first DNA reference library for ~100 Agrilus species from the Northern Hemisphere based on three mitochondrial markers: cox1-5' (DNA barcode fragment), cox1-3', and rrnL. All 329 Agrilus records available in the Barcode of Life Database format, including specimen images and geo data, are released through a public dataset 'Agrilus1 329' available at: dx.doi.org/10.5883/DS-AGRILUS1. All Agrilus species were identified using adult morphology and by using molecular phylogenetic trees, as well as distance- and tree-based algorithms. Most DNA-based species limits agree well with the morphology-based identification. Our results include cases of high intraspecific variability and multiple species para- and polyphyly. DNA barcoding is a powerful species identification tool in Agrilus, although it frequently fails to recover morphologically-delimited Agrilus species-group. Even though the current three-gene database covers only ~3% of the known Agrilus diversity, it contains representatives of all principal lineages from the Northern Hemisphere and represents the most extensive dataset built for DNA-delimited species identification within this genus so far. Molecular data analyses can rapidly and cost-effectively identify an unknown sample, including immature stages and/or non-native taxa, or species not yet formally named.

Cryptic diversity of the jewel beetles Agrilus viridis (Coleoptera: Buprestidae) hosted on hazelnut

The genus Agrilus (Coleoptera: Buprestidae) represents a taxonomic puzzle, since the boundaries between species, subspecies and morphotypes tied to different host plants are sometimes difficult to establish on morphological characteristics alone. Some Agrilus species can cause severe agricultural damage; this makes correct distinctions of the taxon and knowing whether the insects switch from one host plant to another important. This study of mtDNA examined the genetic characteristics of lineages of A. viridis, a jewel beetle recently found causing damage to the hazelnut Corylus avellana in NW Italy. Three mitochondrial markers (a portion of the 12S rDNA and a DNA-fragment including partial NADH dehydrogenase subunit I gene, the tRNA Leucine gene and partial 16S rDNA, and partial Cytochrome c oxidase) were compared between individuals collected on birch Betula sp., beech Fagus sp., willow Salix sp., alder Alnus sp. and hazelnut. We found a high genetic distance between A. viridis sampled on different host plants, while individuals sampled on the same host plant were similar despite a considerable geographic gap between sampled areas. Our study supports the general pattern for strong ecological separation between populations living on different host plants.

Undetected for a century: Palaearctic Agrilus ribesi Schaefer (Coleoptera: Buprestidae) on currant in North America, with adult morphology, larval biology and DNA barcode.

We report the Eurasian species Agrilus ribesi Schaefer, 1946, for the first time from North America and propose that the damage to currants (Ribes spp.) in Ontario prior to 1940 and ascribed to A. cuprescens were caused by this species. We provide morphological diagnostic characters for A. ribesi and closely related A. cuprescens and we complement this information with DNA barcodes from four alien Agrilus species established in North America (i.e., A. ribesi Schaefer, A. cuprescens (Ménétriés), A. planipennis Fairmaire and A. sulcicollis Lacordaire) to enable DNA-based identification of these invasive species. Additionally, published information on A. ribesi is summarized and new data are provided on the host plants and biology of larva in North America. The distribution of A. ribesi is mapped, both in its native Palaearctic region and in Canada and the USA, together with the range of its potential host plants in North America. A. ribesi was recovered as a sister-species of A. cuprescens on the neighbor joining DNA barcoding tree and low genetic variability of North American populations may indicate a single introduction to North America for each of these species.

Invasion potential of Agrilus planipennis and other Agrilus beetles in Europe: import pathways of deciduous wood chips and MaxEnt analyses of potential distribution areas

Bark‐ and wood‐boring beetles in the genus Agrilus (Coleoptera: Buprestidae) can survive wood‐chipping, and Agrilus planipennis has established in North America and European Russia with devastating impacts on forest ecosystems. The work presented in this paper combined import statistics of deciduous wood chips, Maximum entropy modelling (MaxEnt) of climatic similarities, and the distribution of potential tree hosts to predict the likelihood of four selected North American Agrilus species to become introduced and established in Europe. In agreement with the EU's energy‐policy target of increased use of wood chips, there was a linear or exponential increase in European imports of deciduous wood chips during the past 10 years from countries harbouring potentially harmful Agrilus species. MaxEnt showed high environmental suitability in Europe for the four selected Agrilus species, particularly in Eastern Europe and European Russia for A. anxius, A. bilineatus and A. planipennis and in southern Europe for A. politus. Documented susceptible host trees are widely distributed in the predicted areas of Agrilus distribution in Europe, and these areas receive large quantities of deciduous wood chips from countries where these and other Agrilus species are present. Thus, it was concluded that the fundamental conditions for introduction and establishment of Agrilus species in Europe are in place.

Prey carriage varies with prey size in Cerceris fumipennis (Hymenoptera, Crabronidae)

Exploitation of the hunting behavior of the solitary wasp Cerceris fumipennis is proving to be a useful method for detecting pest Buprestidae as well as for documenting buprestid diversity in eastern North America. Here we review prey carriage mechanisms in the species, and conclude that variation in prey carriage is correlated with the spectacular size range of their buprestid prey (4.9–22.3 mm length). Small prey items, including Agrilus species, are transported with the aid of a specialized morphological structure on the fifth metasomal sternite (“buprestid clamp”), resulting in a distinct curved posture during flight. Analysis of prey items from C. fumipennis in North Carolina in 2014 indicates that 30% of collected Agrilus spp. were not paralyzed prior to wasp arrival at the nest, and suggests that the buprestid clamp may function to prevent the escape of active small prey. Recognition that the curved flight posture of a female approaching her nest is a signal that she may be carrying a beetle in the genus Agrilus can improve efficiency of biosurveillance for pest Buprestidae.

Comparison of Buprestidae collected by Cerceris fumipennis (Hymenoptera: Crabronidae) with those collected by purple prism traps

Abstract Detection of low‐level infestations of pest Buprestidae such as emerald ash borer is crucial for their effective management, but the efficiency of trapping techniques varies. In the present study, we compare two nondestructive methods for monitoring metallic wood‐boring beetles. Buprestidae captured by the wasp Cerceris fumipennis Say (Hymenoptera: Crabronidae) were compared with those captured by USDA‐APHIS‐PPQ standard issue purple prism traps (PPTs) at three sites in North Carolina, U.S.A. At each site, four PPTs were hung on trees at the edge of a known C. fumipennis nest aggregation, and changed at 5.5–7.0‐week intervals. Buprestids were collected from hunting wasps once a week during their 5–6‐week activity period. A total of 28 buprestids (seven species) were caught by traps, whereas 267 buprestids (35 species) were collected from C. fumipennis. Of buprestids captured by PPTs, 22 were caught during the pre‐flight period of C. fumipennis, six during their flight period and none during the post‐flight period. One species of Agrilus Curtis was captured by PPTs, while six Agrilus species were captured by wasps. Of the 38 identified buprestid species taken at these sites, only four were recovered at a given location by both methods. Although a standardized comparison of the two techniques is not feasible, C. fumipennis captured a greater number and diversity of Buprestidae than did PPTs. A combination of both techniques may provide the most complete temporal coverage of buprestid activity in a given area, provided that a nesting aggregation of C. fumipennis is available.

A review of Agrilus biguttatus in UK forests and its relationship with acute oak decline

Agrilus biguttatus Fab. (Coleoptera: Buprestidae) is a European bark-boring beetle whose larvae feed in the vascular tissue of oak trees. Until recently, it was considered rare in Britain, but sightings have become more frequent and it is often found on weakened trees suffering from Acute Oak Decline (AOD). This rapidly acting syndrome is characterized by patches of dark sticky fluid exuding from cracks on the trunk, with areas of necrotic tissue beneath, probably caused by a pathogenic bacterial component. However, the frequent association of AOD with the larval galleries and distinctive adult exit holes of A. biguttatus has raised concerns that the beetle may be contributing to the AOD syndrome or hastening the mortality of affected trees. This review evaluates the potential role of A. biguttatus in the AOD complex. Information on the beetle's life cycle and ecology is assessed along with the apparent increase in its abundance and distribution in the UK, and likely mechanisms of host selection. Oak tree defences against the beetle are discussed, as well as risk factors influencing susceptibility. Research on related Agrilus species is reviewed so that insights into the relationship between the beetle, the bacteria and the host tree can be made through comparisons with more extensively studied species. Possible management options in an AOD context are considered, and priority areas for future research are identified.

Buprestidae Collected as Prey by the Solitary, Ground-Nesting Philanthine Wasp Cerceris fumipennis (Hymenoptera: Crabronidae) in North Carolina

ABSTBACT The solitary, ground-nesting crabronid wasp Cerceris fumipennis Say excels at detecting buprestid diversity in a given geographic area, and after the introduction of the invasive pest emerald ash borer (Agrilus planipennis Fairmaire) to the United States in 2002, has been developed as an effective tool for the biosurveillance of pest Buprestidae in eastern North America. Here we report records of Buprestidae collected from foraging C. fumipennis in 13 North Carolina counties over the course of three seasons (2009–2011). Nests of the wasp were located, and beetle prey collected from foraging females in three geographic regions, with a concentration on the western, mountainous area of the state. In total, 909 beetles were collected, comprising 52 buprestid species that included eight native pests and 17 species of Agrilus. Our results emphasize the utility of C. fumipennis in documenting buprestid biodiversity and in detecting forest pests. Eight new state records and five new prey records for the wasp are here recorded.