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Pine wilt disease (PWD) is a devastating plant disease caused by the pinewood nematode (PWN, Bursaphelenchus xylophilus) that is transmitted by several beetle species in the genus, Monochamus. Once present, the disease is difficult to control. Prevention rather than control is regarded as an effective strategy for PWD management. Central to this prevention strategy is the ability to predict the potential distribution of the disease. Here, we employed an integrated MaxEnt and CLIMEX approach to model the potential distribution of PWD under various climate‐change scenarios. Our results indicate that rising temperatures and lower humidity under climate change will render some of the northern regions of China more suitable for the nematode and these beetles, causing the gradual northward movement of PWD. Furthermore, suitable habitats for three pine species, Pinus massoniana, P. taiwanensis and P. shurbergia, overlap with PWN and Monochamus, suggesting that these three species are potentially at high risk of PWD. Thus, PWD management should target the northern regions of China and the three pine species that are most susceptible to PWD. [ABSTRACT FROM AUTHOR]

Pines are the most economically important trees in the world and, together with eucalyptus, they dominate commercial forests. But the success of a relatively small number of widely planted species, such as Pinus pinaster, the maritime pine, comes at a price. Pines are attractive to damaging pathogens and insect pests, including the pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD). Originally described in Japan, PWD has caused widespread destruction to forests in countries such as China, Taiwan, Portugal, Spain and the United States. PWN causes irreparable damage to the vascular system of its pine hosts, leading to mortality within 3 months. Pine sawyer beetles (Monochamus spp.) are key vectors of PWD, introducing the PWN to healthy trees during feeding. Other organisms contribute to PWD spread and development, including bacteria, fungi and bark beetles. Control measures include tree felling to prevent vector transmission of PWN, insecticide treatments, trapping of Monochamus spp. and tree breeding for plant resistance. The PWN is a quarantine pathogen and subject to regular legislation and phytosanitary measures aimed at restricting movement and preventing introduction to new areas. Current research is investigating the use of biopesticides against PWN and Monochamus spp. This review examines the biology, epidemiology, impact and management of PWD through published research, grey literature and interviews with people directly involved in the management of the disease in Portugal. [ABSTRACT FROM AUTHOR]

Abstract Pine wilt disease (PWD) is a devastating plant disease caused by the pinewood nematode (PWN, Bursaphelenchus xylophilus) that is transmitted by several beetle species in the genus, Monochamus. Once present, the disease is difficult to control. Prevention rather than control is regarded as an effective strategy for PWD management. Central to this prevention strategy is the ability to predict the potential distribution of the disease. Here, we employed an integrated MaxEnt and CLIMEX approach to model the potential distribution of PWD under various climate‐change scenarios. Our results indicate that rising temperatures and lower humidity under climate change will render some of the northern regions of China more suitable for the nematode and these beetles, causing the gradual northward movement of PWD. Furthermore, suitable habitats for three pine species, Pinus massoniana, P. taiwanensis and P. shurbergia, overlap with PWN and Monochamus, suggesting that these three species are potentially at high risk of PWD. Thus, PWD management should target the northern regions of China and the three pine species that are most susceptible to PWD.

Abstract Key message The invasive pine wood nematode is a major threat to pine forests worldwide, causing extensive tree mortality. Although scientific knowledge and control measures are continuously improving, important gaps remain. We argue that some key questions, notably related to early detection and pest management, need to be urgently tackled in countries at risk of invasion such as France.

Monochamus alternatus Hope, 1842, is a major forest pest that hosts the pathogenic pinewood nematode (PWN), Bursaphelenchus xylophilus (Steiner and Buhrer, 1934) Nickle 1970. Taxonomically, M. alternatus is currently divided into two subspecies, based on morphology and geography: Monochamus alternatus alternatus Hope, 1842 in China, Taiwan, Tibet, Vietnam, and Laos and Monochamus alternatus endaiMakihara, 2004 in South Korea and Japan. Despite their economic importance, the subspecies taxonomy of M. alternatus has never been tested after the first description. In this study, we aimed to reassess the subspecies taxonomy of M. alternatus using molecular and morphological data. For morphological analysis, we examined three major morphological characters (pronotal longitudinal band, granulation on humeri, and elytral proximomedial spine) from 191 individuals from China, Korea, and Taiwan. Population genetic structures were examined using 85 de novo sequences and 82 public COI sequences from China, Korea, Japan, Malaysia, Taiwan, and a few intercepted specimens from the United States. All the genetic data were aligned as three different multiple sequence alignments. Individuals from each subspecies were morphologically and genetically scattered, not clustered according to subspecies in any of the analyses. Therefore, a new synonymy is proposed: Monochamus alternatus Hope, 1842 = Monochamus alternatus endai, syn. n. This study suggests a more robust classification of M. alternatus for the first time and ultimately will pose a substantial impact on implementing quarantine or forestry policies. [ABSTRACT FROM AUTHOR]

Ips bark beetles (Ips species; Coleoptera: Curculionidae: Scolytinae) play an important role in forest ecosystems by attacking injured, stressed, or dying pine (Pinus) trees. Management of Ips bark beetles has largely focused on prevention by maintaining tree health through silvicultural treatments including thinning to reduce basal area or prescribed fire. However, there is conflicting evidence of whether prescribed fire leads to increased bark beetle populations and, subsequently, increased tree mortality. Recent outbreaks of Ips bark beetles in the southeastern U.S. have caused renewed interest in the interactions between pine management and bark beetle populations. We monitored Ips populations following prescribed fire in intensively managed pine stands and quantified Ips damage. We captured over 361,000 Ips bark beetles with I. avulsus being the most abundant of the three species collected. While we found high variation among Ips populations across study sites and years, there was a significant increase in bark beetle populations after prescribed fire followed by a significant decline the next year. While Ips populations increased up to three-fold after prescribed burns, damage ratings in burned stands were no different than unburned stands which had significantly lower bark beetle populations. Unburned stands had higher basal area and a higher average tree damage rating, but the lowest number of Ips bark beetles. A total of 14,071 facultative (e.g., Monochamus = 9775) and obligate (e.g., Thanasimus dubius = 4296) predators were collected during the study across all sites and the ratio of predators: Ips also significantly increased following prescribed fire. These data suggest that while Ips are ubiquitous and abundant in pine forests being managed with prescribed fire, natural mechanisms such as predator activity mediate their overall damage and impact to southeastern pine stands. • Ips bark beetles are ubiquitous in pine stands regardless of damage or mortality. • Prescribed fire results in significant increases in bark beetle trap collections. • Natural enemies also increase significantly in response to prescribed fire. • Two years after prescribed fire, Ips bark beetles decline, likely due to predators. [ABSTRACT FROM AUTHOR]

The Japanese pine sawyer (JPS) beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae), damages pine trees and transmits the pine wilt nematode, Bursaphelenchus xylophilus Nickle. Chemical agents have been used to control JPS beetle, but due to various issues, efforts are being made to replace these chemical agents with entomopathogenic fungi. We investigated the expression of immune-related genes in JPS beetle in response to infection with JEF-197, a Metarhizium anisopliae isolate, using RNA-seq. RNA samples were obtained from JEF-197, JPS adults treated with JEF-197, and non-treated JPS adults on the 8th day after fungal treatment, and RNA-seq was performed using Illumina sequencing. JPS beetle transcriptome was assembled de novo and differentially expressed gene (DEG) analysis was performed. There were 719 and 1953 up- and downregulated unigenes upon JEF-197 infection, respectively. Upregulated contigs included genes involved in RNA transport, ribosome biogenesis in eukaryotes, spliceosome-related genes, and genes involved in immune-related signaling pathways such as the Toll and Imd pathways. Forty-two fungal DEGs related to energy and protein metabolism were upregulated, and genes involved in the stress response were also upregulated in the infected JPS beetles. Together, our results indicate that infection of JPS beetles by JEF-197 induces the expression of immune-related genes. [ABSTRACT FROM AUTHOR]

Abstract 1. Pine wilt disease, caused by pinewood nematode (Bursaphelenchus xylophilus; abbreviated ‘PWN’), is a damaging and globally distributed insect‐vectored forest pathogen. Native forest tree mortality associated with PWN is newly reported from the Front Range of Colorado, but there is no regional information on PWN frequency or biology of local insect vectors, limiting management options. 2. A sampling array was established to survey PWN in native pines (Pinus ponderosa) and longhorn beetles (Monochamus clamator and M. scutellatus) over 2 years and across natural and urban forest landscapes. We developed flight phenology models and evaluated effects of landscape factors on vector abundance and probability of infection. 3. Flight phenology was similar for vectors; Monochamus flight initiated in mid‐July and continued into October for both species. We report the first M. clamator–PWN association in the United States. PWN was distributed in the region at rates lower than reported from its putative native range: 3.6 and 4.2% of sampled pines and beetles, respectively, tested positive for PWN. Many host trees were outwardly asymptomatic; infection frequency in tree populations varied considerably and four epicentres of vector infectivity were identified. 4. Epicentres varied in timing of anomalous infective vector frequency – some epicentres had high abundances of infected beetles early in the growing season whereas others had high abundances of infected beetles late in the growing season, though PWN‐positive beetles were captured at all sites. Monochamus populations were found primarily in natural forest stands but migrated to urban areas late in the growing season. The only landscape factor positively correlated with abundances of both Monochamus species was distance to previous wildfire. 5. PWN epicentres in the southern Rocky Mountains exhibit specific temporal windows of vector activity that differ from proximal sites. Urban forests, where the disease was initially observed in the region, do not support vector populations. Our results suggest that natural forest landscapes in the region are important reservoirs of PWN, and vector populations are especially abundant near burned stands. Collectively, our findings are important for timing disease management activities appropriately and help to distinguish priority areas for mitigation efforts.

The importance of interspecific competition in structuring communities of plant-eating insects has been somewhat controversial. If interspecific competition is ever important for phytophagous insects, it is likely to be observed in the insect guild that feeds in the phloem of trees. We tested for signals of interspecific competition in co-occurring species of pine sawyer beetles Monochamus Megerle (Coleoptera Cerambycidae), generally the largest phloemophagous insects in pines. We evaluated patterns of body size and its correlation with other life-history traits. By studying pine sawyer beetles in different areas (Northeast USA, Southeast USA and Portugal) we assessed the interaction with climate. As predicted under the hypothesis of interspecific competition, there were always clear size differences among coexisting species. As predicted if competition is asymmetric, smaller species were less abundant and emerged earlier than the larger species. In the larger and numerically dominant species, sexual size dimorphism was more pronounced and the sex ratio was skewed towards females. In the smaller species, males emerged earlier (protandry), whereas the larger species lacked differences in emergence time or displayed protogyny. Effects of climate only seem to have been expressed in the larger dominant species of each area, whereas the effects of competition in smaller species probably overshadow the effects of climate. [ABSTRACT FROM AUTHOR]

Studies have demonstrated that semiochemical-baited intercept traps differ in their performance for sampling insects, but we have an incomplete understanding of how and why intercept trap design effects vary among insects. This can significantly delay both the development of new and optimization of existing survey and detection tools. The development of a mechanistic understanding of why trap performance varies within and among species would mitigate this delay. The primary objective of this study was to develop methods to characterize and compare the odor plumes associated with intercept traps that differ in their performance for forest Coleoptera. We released CO2 and measured fluctuations of this tracer gas from 175-point locations arranged in a 2-by-3-by-2-m grid cuboid downwind of a standard multiple-funnel, a modified multiple-funnel, a panel, a canopy malaise trap, and a blank control (i.e., no trap) in a greenhouse. Significant differences in trapping efficacy between these different trap designs were observed for Monochamus scutellatus (Say) and Monochamus notatus (Drury) in a field trial. Significant differences were also observed in how CO2 accumulated in time at different positions downwind among these different trap designs. Turbulent dispersion is the dominant force structuring odor plumes and creates intermittency in the odor plume that is important for sustained upwind flight in insects. Methodological and instrumental limitations resulted in the inability to determine instantaneous plume structures and vortex shedding frequencies for different intercept trap designs. Although we observed differences in the odor plumes emanating downwind of the different intercept trap designs, we were unable to reconcile these differences with capture rates of the different trap designs for M. scutellatus and M. notatus. [ABSTRACT FROM AUTHOR]

This pest survey card was prepared in the context of the EFSA mandate on plant pest surveillance (M‐2017‐0137) at the request of the European Commission. The purpose of the document is to assist the Member States to plan annual survey activities of quarantine organisms using a statistically sound and risk‐based pest survey approach, in line with current international standards. The data requirements for such an activity include the pest distribution, its host range, its biology and risk factors, as well as available detection and identification methods. This document is part of a toolkit that consists of pest‐specific documents, such as the pest survey cards, and generic documents relevant for all pests to be surveyed, including the general survey guidelines and statistical software such as RiBESS+. [ABSTRACT FROM AUTHOR]

The article shows the study of some quarantine insects and nematodes at the Botanical Garden of PetrSU. They were caught with pheromone traps. Quarantine species of sawyers of Monochamus genus were caught in the territory. They both destruct wood, causing its quality decrease, and transmiss nematodes of Bursaphelenhus genus. The article includes a quantity analysis of the nematodes' appearances and their dependence on the distance of roads. Lepidopterans that pose a threat to the forest sector, such as the Asian type of a Gypsy and Siberian silkworms were not discovered.

Pheromone traps are widely used for monitoring or managing insect pest populations. However, it is important to know their range of attraction to optimize the setting of pheromone trap networks.We propose an easy method based on the use of pairs of adjacent traps located at decreasing distance from each other. The range of attraction is deduced from the observation of reduced trap capture when the attraction range of two adjacent traps starts overlapping. The relationship between the relative trap capture and the distance between paired traps is fitted with a logistic curve.To empirically test these predictions, we conducted trapping experiments with the beetle Monochamus galloprovincialis, the insect vector of the pine wood nematode. Fifteen pairs of traps separated by 25 to 300 m, in France, and 18 pairs of traps distant from 25 to 400 m, in Portugal, were installed in maritime pine plantation landscapes.In both countries, the relative percentage of capture per trap per week was best fitted by a logistic model with two parameters. The estimated attraction ranges were 92 m (confidence interval = 62–211 m) in France and 123 m (confidence interval = 64–491 m) in Portugal.The interference between paired traps thus provides a simple and robust method for estimating the attraction range of pheromone traps. [ABSTRACT FROM AUTHOR]

Pine wilt disease is one of the most serious introduced threats to coniferous forests worldwide. Its causal agent, the pinewood nematode (PWN), Bursaphelenchus xylophilus, is vectored primarily by cerambycids of the genus Monochamus Dejean throughout its native (North America) and introduced (Japan, China, Korea, Taiwan, Portugal) ranges. Despite strict import regulations and phytosanitary measures, interception records indicate that PWN and Monochamus species continue to be moved worldwide. Following its introduction in Portugal in the late 1990s, extensive monitoring programs for PWN and its vectors have been conducted throughout the European Union, using locally developed and tested lures and traps. The trapping system developed in Europe and used in this study is composed of a Crosstrap® and Galloprotect Pack® lures. These trapping systems were deployed in two locations in the USA, two locations in Canada, and one location in China in order to test their capacity to detect Monochamus species exotic to Europe. Large numbers of M. carolinensis, M. mutator, M. notatus, M. s. scutellatus, M. clamator, and M. titillator were trapped in North America, while large numbers of M. alternatus were trapped in China. The trapping systems developed in Europe for monitoring the European Monochamus species are also effective for the detection of many exotic Monochamus species and could thus be used as an early detection tool in ports and other high-risk sites. [ABSTRACT FROM AUTHOR]

Monochamus saltuarius has a morphological polymorphism, but there is no standard phenotype to distinguish the differences in M. saltuarius species. To investigate molecular diversity of M. saltuarius, mitochondrial cytochrome c oxidase I 5’ sequence were analyzed against specimens collected from Chungbuk, Gyeonggi, and Gangwon province. The DNA barcode results showed that the specimens make two groups with a 1.68%–3.1% K2P distance, but cannot find a specific phenotype difference among the specimens.

Specific scope: This Standard describes the procedures for official control with the aim of eradicating or containing Bursaphelenchus xylophilus. Specific approval and amendment: First approved in 2002‐09. First revision approved in 2009‐09. Second revision approved in 2010‐09. Third revision approved in 2011‐09. Fourth revision (editorial changes only) approved in 2012‐09. Fifth revision approved in 2018‐09 [ABSTRACT FROM AUTHOR]

Invasions by insects introduced via international trade continue to cause worldwide impacts. Surveillance programs using traps baited with host volatiles and pheromones can detect incursions of nonnative species. We report on two experiments executed to determine if attractants for several insect species can be combined without compromising trap catches and detection ability of target species. In the first experiment, we tested the effect of bark beetle pheromones (plus α-pinene) and trap contact with foliage on trap catches of the brown marmorated stink bug Halyomorpha halys Stål (Hemiptera: Pentatomidae) in traps baited with a mixture of bisabolenes and methyl (E,E,Z)-2,4,6-decatrienoate. Trap capture of H. halys adults was greater in traps not in contact with foliage, and the bark beetle pheromones ipsenol and ipsdienol did not affect trap capture of H. halys. In the second experiment, we tested the effects of multi-lure interactions among the primary host attractants α-pinene and ethanol, and the pheromones monochamol, ipsenol, ipsdienol, lanierone, and the H. halys compounds, on trap captures of various forest and agricultural insect pests. Specifically, we targeted Monochamus spp. (Coleoptera: Cerambycidae), Ips spp. (Coleoptera: Scolytinae) and H. halys. We found that a combination of all lures did not catch significantly lower numbers of Monochamus carolinensis Olivier, Monochamus scutellatus Say (Coleoptera: Cerambycidae), and Ips pini Say (Coleoptera: Scolytidae) than lure combinations missing components although removal of both lanierone and ipsdienol somewhat increased catches of Ips grandicollis Eichhoff (Coleoptera: Curculionidae). Our results support the use of traps baited with a full combination of these attractants in surveillance programs. This should reduce costs and increase detection rates of a wider range of conifer forest pests and H. halys. [ABSTRACT FROM AUTHOR]

Abstract: The aggregation pheromone of Monochamus (Coleoptera: Cerambycidae) beetles, 2‐(undecyloxy) ethanol (hereafter referred to as monochamol), has gained considerable attention because of its usefulness in monitoring and population control of pine sawyer beetles. The hydroxyether structural motif is conserved in pheromones of the subfamily Lamiinae of the Cerambycidae. In this study, we investigated the effects of C10‐ and C12‐chain length alkyl analogs of monochamol, 2‐(decyloxy) ethanol and 2‐(dodecyloxy) ethanol, on attracting M. saltuairus in Andong, Gyeongsangbuk‐do, Korea. The C10 and C12 analogs attracted M. saltuarius when used in combination with α‐pinene and ethanol, but the responses of these alkyl chain analogs were lower than those of monochamol. Furthermore, the addition of either C10 or C12 analog to the use of monochamol with α‐pinene and ethanol had no effect on attraction of M. saltuarius, indicating high sensitivity of M. saltuarius to monochanol. Taken together, the results of this study suggest that chemical communication within a Monochamus species depends not only on monochamol, but also on other semiochemicals. [ABSTRACT FROM AUTHOR]

The genus Monochamus Dejean (Coleoptera: Cerambycidae) includes large, woodboring, longhorned beetles, which colonize pine trees in North America. Many authors have classified the genus as saprophagous, but one recent study reported successful colonization of standing jack pine trees (Pinus banksiana Lamb.) (Pinales: Pinaceae) following severe wind disturbance in Minnesota. We tested whether two Monochamus species native to the southeastern United States (M. titillator (Fabricius) and M. carolinensis (Olivier)) could successfully colonize healthy shortleaf pines (Pinus echinata Mill.) (Pinales: Pinaceae) in recently harvested stands without coincident abiotic or biotic stressors, such as lightning strikes or bark beetle attacks. We attached commercially available semiochemical lures, including monochamol, ethanol, and ipsenol, to healthy shortleaf pine trees and observed Monochamus spp. oviposition response. Egg development was monitored following oviposition by harvesting attacked trees and dissecting oviposition pits. High numbers of oviposition pits were observed on trees treated with lures containing the bark beetle pheromone ipsenol and pits were highly concentrated on the tree bole near lures. Although egg deposition occurred, pit dissection revealed large amounts of resin present in almost all dissected pits and that egg hatch and subsequent larval development were rare. Our results demonstrate that southeastern Monochamus spp. are unlikely to be primary pests of healthy shortleaf pines due to resinosis. To better understand the host finding behavior of these two Monochamus species, we also conducted trapping trials with several semiochemical combinations. Both species and sexes demonstrated similar attraction to compounds, and the most attractive lure combined host volatiles, pheromone, and sympatric insect kairomone. [ABSTRACT FROM AUTHOR]

Abstract: Pine wilt disease (PWD) is caused by pine wood nematode (PWN), Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, transmitted by Monochamus saltuarius (Gebler) (Coleoptera: Cerambycidae) to healthy Korean white pine, Pinus koraiensis Siebold & Zucc. (Pinaceae). It is a serious threat to forest ecosystems worldwide. To better understand and predict the spread of PWD in Korean white pine forests, we investigated flight distance, time, and velocity of M. saltuarius adults using computer‐linked flight mills under laboratory conditions. In addition, we investigated the impact of biological characteristics on flight distance of this vector insect. Flight distance and time were individually measured during flight mill experiments (30 min per session) and repeatedly measured twice a week. Our results revealed large variation in flight distance within the population. Half of the beetles tested in this study flew more than 1 km and no difference was found between males and females when only fliers were considered. The average flight velocity of females was higher than that of males, but intermittent flights were observed more frequently in males compared to females. Both unmated male and female M. saltuarius adults can fly more than 5 km during their entire lifespan based on these flight mill experiments. Consequently, guidelines for managing dead pines in infected areas should consider a large buffer zone around PWN‐invaded areas so that uninfected areas are beyond the dispersal capacity of M. saltuarius. [ABSTRACT FROM AUTHOR]

The Sakhalin pine longicorn, Monochamus saltuarius (Gebler; Coleoptera: Cerambycidae), is an insect vector of the pine wilt nematode (PWN), Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle, and is widely distributed in central Korea. M. saltuarius is a forest pest that seriously damages Pinus densiflora (Siebold et Zucc, Pinales: Pinaceae) and Pinus koraiensis (Siebold & Zucc, Pinales: Pinaceae) forests. We examined the effect of electron beam irradiation on the mating, DNA damage and ovarian development of M. saltuarius adults and sought to identify the optimal dose for sterilizing insects. When the adults were irradiated with electron beams, both females and males were completely sterile at 200 Gy. In a reciprocal crossing experiment between unirradiated and irradiated adults, the reproductive ability of wild adults was recovered by crossing with wild adults even after crossing previously with sterile adults. When a pair of unirradiated adults (♀- × ♂-) and 10 or 20 irradiated adults (♀+ or ♂+) were kept together, the control effect was as high as 80~90%. After electron beam irradiation at 200 Gy, the DNA of M. saltuarius adults was damaged, the ovarian development of female adults was inhibited, and the level of vitellogenin was significantly decreased compared with that in unirradiated female adults. These results suggest that pine wilt disease can be effectively controlled if a large number of sterilized M. saltuarius male adults are released into the field. [ABSTRACT FROM AUTHOR]

To clarify the ability of Monochamus grandis to carry Bursaphelenchus xylophilus, we transferred B. xylophilus to M. grandis and M. alternatus (the vector beetle of B. xylophilus) using a simple nematode-loading method. We examined: i) the effects of M. grandis on the formation of the fourth-stage dispersal juvenile (JIV) of B. xylophilus, the phoretic stage carried by vector beetles; and ii) whether JIV of B. xylophilus transferred to M. grandis, and compared the ability of M. grandis to carry B. xylophilus with that of M. alternatus. Monochamus grandis induced JIV formation and carried similar numbers of JIV as M. alternatus. Moreover, the percentage of JIV transferred to M. grandis to total JIV was higher than for M. alternatus. We concluded that M. grandis had potentially an equal ability to M. alternatus to carry B. xylophilus. [ABSTRACT FROM AUTHOR]

We reconstructed the phylogeography of European populations of Monochamus galloprovincialis (Coleoptera, Cerambycidae), the European vector of the pinewood nematode, Bursaphelenchus xylophilus. This study investigated the Quaternary history of M. galloprovincialis and tested whether environmental parameters and/or host tree species influenced the genetic structure of M. galloprovincialis populations. Twelve polymorphic microsatellite loci and a Bayesian analysis were applied to 1098 individuals of M. galloprovincialis from 45 European locations. The continental populations formed five main genetic clusters, typical of postglacial recolonization routes observed for temperate biota associated with pine trees. The distribution of clusters formed boundaries along mountain ranges, indicating a potential role of elevation as a large-scale barrier to dispersal for this species. The correlation between environmental parameters and the distribution of genetic clusters of M. galloprovincialis was investigated using a partial redundancy analysis and showed an effect of precipitation rather than host tree species. From an applied perspective, these results suggest that climatic conditions and elevation may constitute barriers to the dispersal of M. galloprovincialis and the associated PWN. [ABSTRACT FROM AUTHOR]

The use of multiple sampling areas in landscape genetic analysis has been recognized as a useful way of generalizing the patterns of environmental effects on organism gene flow. It reduces the variability in inference which can be substantially affected by the scale of the study area and its geographic location. However, empirical landscape genetic studies rarely consider multiple sampling areas due to the sampling effort required. In this study, we explored the effects of environmental features on the gene flow of a flying long-horned beetle (Monochamus galloprovincialis) using a landscape genetics approach. To account for the unknown scale of gene flow and the multiple local confounding effects of evolutionary history and landscape changes on inference, we developed a way of resampling study areas on multiple scales and in multiple locations (sliding windows) in a single large-scale sampling design. Landscape analyses were conducted in 3*104 study areas ranging in scale from 220 to 1,000 km and spread over 132 locations on the Iberian Peninsula. The resampling approach made it possible to identify the features affecting the gene flow of this species but also showed high variability in inference among the scales and the locations tested, independent of the variation in environmental features. This method provides an opportunity to explore the effects of environmental features on organism gene flow on the whole and reach conclusions about general landscape effects on their dispersal, while limiting the sampling effort to a reasonable level. [ABSTRACT FROM AUTHOR]

The pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease. This nematode has two developmental forms in its life cycle; i.e., the propagative and dispersal forms. The former is the form that builds up its population inside the host pine. The latter is specialized for transport by the vector. This form is separated into two dispersal stages (third and fourth); the third-stage dispersal juvenile (JIII) is specialized for survival under unfavorable conditions, whereas the fourth-stage juvenile (JIV), which is induced by a chemical signal from the carrier Monochamus beetle, is transported to new host pines and invades them. Because of its importance in the disease cycle, molecular and chemical aspects of the JIV have been investigated, while the mechanism of JIII induction has not been sufficiently investigated. In an effort to clarify the JIII induction process, we established inbred lines of B. xylophilus and compared their biological features. We found that the total number of nematodes (propagation proportion) was negatively correlated with the JIII emergence proportion, likely because nematode development was arrested at JIII; i.e., they could not develop to adults via the reproductive stage. In addition, JIII induction seemed to be regulated by a small number of genes because the JIII induction proportion varied among inbred lines despite the high homozygosity of the parental line. We also demonstrated that JIII can be artificially induced by the nematode’s secreted substances. This is the first report of artificial induction of JIII in B. xylophilus. The dauer (dispersal) juvenile of the model organism Caenorhabditis elegans corresponds functionally to JIII of B. xylophilus, and this stage is known to be induced by a chemical signal referred to as daumone, derived from the nematodes’ secretion. The artificial induction of JIII suggests the presence of daumone-like material in B. xylophilus. [ABSTRACT FROM AUTHOR]

In this study, we isolated and identified an aggregation-sex pheromone from Monochamus saltuarius, the major insect vector of the pine wood nematode in Korea. Adult males of M. saltuarius produce 2-undecyloxy-1-ethanol, which is known as an aggregation-sex pheromone in other Monochamus species. We performed field experiments to determine the attractiveness of the pheromone and other synergists. More M. saltuarius adult beetles were attracted to traps baited with the pheromone than to unbaited traps. Ethanol and (−)- α-pinene interacted synergistically with the pheromone. Traps baited with the pheromone + (−)- α-pinene +ethanol were more attractive to M. saltuarius adults than traps baited with the pheromone, (−)- α-pinene, or ethanol alone. Ipsenol, ipsdienol, and limonene were also identified as synergists of the aggregation-sex pheromone for M. saltuarius adults. In field experiments, the proportion of females was much higher in the beetles caught in traps than among the beetles emerging from naturally-infested logs in the laboratory. Our results suggest that a combination of aggregation-sex pheromone and synergists could be very effective for monitoring and managing M. saltuarius. [ABSTRACT FROM AUTHOR]

Ecologists have explored widely the consequences of climate change on insect species distribution and fitness. Although most studies have assessed the effect of increasing mean temperatures on individual performances, the response to temporal thermal variations, including the magnitude and frequency of extreme temperatures, has often been overlooked., In the present study, we hypothesized that insect performances increase with increasing mean temperatures but decrease under more variable thermal conditions. We used a manipulative experiment to compare the longevity and weight variation of Monochamus galloprovincialis ( Coleoptera: Cerambycidae) under three climatic conditions in which the mean and variance of daily temperatures were both controlled. This insect is vector of the invasive nematode, Bursapheluncus xylophilus, which is the causal agent of the pine wilt disease, one of the major threats to pine forests in Europe., Our results showed that an increase of 2.5 ° C in average temperature had no effect on the survivorship and weight variations of the beetle. By contrast, larger fluctuating variations of temperature across year resulted in significantly lower longevity, whereas weight remained unchanged., The results of the present study suggest that the effect of global warming on the survival of M. galloprovincialis is likely to be driven by change in temperature stability rather than by change in mean temperature. [ABSTRACT FROM AUTHOR]

Pine wood nematode ( PWN), Bursaphelenchus xylophilus, is a threat for pine species ( Pinus spp.) throughout the world. The nematode is native to North America, and invaded Japan, China, Korea, and Taiwan, and more recently Portugal and Spain. PWN enters new areas through trade in wood products. Once established, eradication is not practically feasible. Therefore, preventing entry of PWN into new areas is crucial. Entry risk analysis can assist in targeting management to reduce the probability of entry. Assessing the entry of PWN is challenging due to the complexity of the wood trade and the wood processing chain. In this paper, we develop a pathway model that describes the wood trade and wood processing chain to determine the structure of the entry process. We consider entry of PWN through imported coniferous wood from China, a possible origin of Portuguese populations, to Europe. We show that exposure increased over years due to an increase in imports of sawn wood. From 2000 to 2012, Europe received an estimated 84 PWN propagules from China, 88% of which arose from imported sawn wood and 12% from round wood. The region in Portugal where the PWN was first reported is among those with the highest PWN transfer per unit of imported wood due to a high host cover and vector activity. An estimated 62% of PWN is expected to enter in countries where PWN is not expected to cause the wilt of pine trees because of low summer temperatures (e.g., Belgium, Sweden, Norway). In these countries, PWN is not easily detected, and such countries can thus serve as potential reservoirs of PWN. The model identifies ports and regions with high exposure, which helps targeting monitoring and surveillance, even in areas where wilt disease is not expected to occur. In addition, we show that exposure is most efficiently reduced by additional treatments in the country of origin, and/or import wood from PWN-free zones. Pathway modelling assists plant health managers in analyzing risks along the pathway and planning measures for enhancing biosecurity. [ABSTRACT FROM AUTHOR]

Bursaphelenchus xylophilus is an insect-vectored pathogen and the causal agent of the pine wilt disease (PWD). In Portugal, where B. xylophilus is a recent invasive pest, the native pine sawyer beetle, Monochamus galloprovincialis, is its only vector. Epidemics of PWD emerge from three-way interactions among B. xylophilus , M. galloprovincialis , and host pine trees. However, the basic ecology of these interactions is poorly known. We studied M. galloprovincialis with respect to its life history, host selection, and phoresy by B. xylophilus in an area severely affected by PWD in Portugal. We assessed: (1) seasonal patterns of phoresy related to the flight phenology of the vector; and (2) distribution of M. galloprovincialis within and among host pine trees. Monochamus galloprovincialis in Portugal flies from May through October, and is probably bivoltine, but phoresy by B. xylophilus only occurs within a short period in early summer, when infection of new pine hosts most likely occurs. Peaks of M. galloprovincialis emergence and B. xylophilus phoresy immediately precede onset of the Mediterranean dry season, favoring PWD because B. xylophilus succeeds best on trees suffering from severe water deficits. The abundance of phoretic nematodes was more evident when their vectors were trapped as free flying adults rather than emerging from dying trees. Bursaphelenchus xylophilus were highly aggregated on a subset of M. galloprovincialis , which were aggregated in a subset of dying trees. However none of the host parameters related to size and bark thickness, could explain host selection. Despite its importance for PWD, M. galloprovincialis is a minor component of the bark and wood-boring insects of pine trees in Portugal. Interactions within this community are likely important to the epidemiology of PWD. [ABSTRACT FROM AUTHOR]

Monochamus (Coleoptera: Cerambycidae) species are longhorn pine sawyers that serve as insect vectors of the pinewood nematode Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae), which are responsible for debilitating pine wilt disease. An aggregation pheromone, 2-(1-undecyloxy)-1-ethanol (hereafter referred to as monochamol), was shown to be effective at attracting Monochamus species. However, attraction of the pine sawyers to aggregation pheromones varied depending on semiochemicals, including host plant volatiles and kairomones. In this study, we investigated the abilities of monochamol and the host-plant volatiles α-pinene and ethanol to attract M. saltuarius in a pine forest in Cheongsong, Gyeongsangbuk-do, Korea. A total of 91 M. saltuarius (28 males and 63 females) were captured. The combination of monochamol (700 mg) with α-pinene and ethanol exhibited a synergistic effect on attracting M. saltuarius (11.0 beetles per trap), whereas monochamol alone and a mixture of α-pinene and ethanol resulted in the capture of 3.2 beetles and 3.6 beetles per trap, respectively. Our results suggest that multi-funnel traps baited with a blend of monochamol, α-pinene and ethanol are highly effective for monitoring M. saltuarius and M. alternatus in pine forests. [ABSTRACT FROM AUTHOR]

Monochamus sutor (Linnaeus) (Coleoptera: Cerambycidae) is a secondary wood borer that has been hypothesized as capable of transmitting Bursaphelenchus xylophilus, the causal agent of pine wilt disease ( PWD). This fact supposes a risk of spread of PWD over Europe and has created an urgent need for effective tools to detect and monitor both the nematode and the insect species that vectors it. Recent reporting of 2-undecyloxy-1-ethanol as the M. sutor male-produced aggregation pheromone has opened the possibility of developing an efficient lure for this species. It is known that some European bark beetle pheromone compounds and host volatiles kairomonally attract this species. Besides, smoke volatiles from burnt trees might play a role in M. sutor host location. In this work, field trapping experiments during 3 years in three countries (Spain, Sweden and Austria), aimed to develop an efficient pheromone-kairomone lure operative for M. sutor management were carried out. Electroantennographic responses by M. sutor to Ips pheromones and to the Pityogenes chalcographus pheromone chalcogran were also studied. GC- EAG recording showed that M. sutor males and females clearly responded to ipsenol and ipsdienol, and females also responded to 2-methyl-3-buten-2-ol. Chalcogran elicited a response to M. sutor female antennae. In field tests, ipsenol was the most attractive kairomone to both sexes of M. sutor, whereas ipsdienol, cis-verbenol and 2-methyl-3-buten-2-ol were attractive and chalcogran was unattractive. When combined with the pheromone, most bark beetle kairomones increased catches of both sexes although chalcogran was completely ineffective. Thus, ipsenol was the strongest individual kairomone for M. sutor and the best single kairomone to be combined with the pheromone. Smoke volatile blends tested in Spain and Austria did not elicit responses, suggesting that these compounds are likely not involved in host finding by this species. [ABSTRACT FROM AUTHOR]

Novel associations between exotic pathogens and native insects may result in major ecological and economical losses. In Europe, Monochamus galloprovincialis ( Olivier) ( Coleoptera: Cerambycidae) is the only known vector of the exotic pine wood nematode Bursaphelenchus xylophilus ( Steiner & Buhrer) Nickle ( Nematoda: Aphelenchoididae), the causal agent of pine wilt disease ( PWD). Transportation of goods containing nematode-infested beetles is the main pathway for the spread of the disease. In this scenario, management actions involving early detection and eradication are critical to stop further spread by the vector. Although dispersal of mature M. galloprovincialis has been successfully tracked using commercial baits and traps, dispersal ability of immature individuals is poorly understood. Sexual maturation and other physiological traits related to dispersal were studied for newly emerged M. galloprovincialis after different shoot-feeding spans. Sexual maturation was complete after on average 12 (males) or 13 (females) feeding days. Monochamus galloprovincialis adults emerged with an average of 10% lipid and 23.8% (males) or 29.9% (females) pterothorax muscle content, and these percentages did not change significantly during shoot feeding. Microtomography images of wing muscle structures at different maturation stages confirmed these results. Emerged adults that were kept unfed survived an average of 12 days in the lab. The ability of unfed immature insects to fly through hostless terrain was studied by marking and releasing newly emerged insects from a crop area located up to 3 km away from two small pine stands. The longest flown distance recorded was 2 km. Fitted regressions indicated that immature insects could have travelled up to 3 109 m to reach the experimental stands. We found that M. galloprovincialis emerge with well-developed thoracic muscles and energy reserves that enable them to sustain long flights over non-forested areas. These findings should aid managers and policy makers in devising sound procedures in areas where the risk of introducing PWD is high. [ABSTRACT FROM AUTHOR]

Monochamus saltuarius was recently identified as an important vector of Bursaphelenchus xylophilus, the cause of pine wilt disease. In this study, M. saltuarius adults preferred different species of tree based on the longevity, ingested amount and wounded area that were determined for 90 d. Among eight tree species, the longevity of feeding by M. saltuarius was not significantly different except when feeding in Sciadopitys verticillata. However, the highest ingested amounts with the largest wounded areas were associated with Pinus koraiensis. The highest oviposition preference was in P. densiflora for the first 20 d. However, after 40 d, the oviposition highest preference was noted in P. koraiensis. For oviposition activities, M. saltuarius preferred the tree species in the following order: P. densiflora > P. koraiensis > P. rigida > Larix leptolepis. Although many oviposition scars were observed, M. saltuarius laid fewer eggs in P. rigida than other species of pine, which was related to the bark thickness. The oviposition frequencies were highest with bark 2.0-2.5 mm thick and with tree diameters of 110-130 mm. The current study increased understanding of the ecology of M. saltuarius by identifying specific tree preferences. [ABSTRACT FROM AUTHOR]

During the process of slow decay, dead wood is colonized by a diverse group of invertebrates. Pioneer communities of insects are composed of representatives of two families of beetles: Cerambycidae and Curculionidae, which may be carriers for mites. In this paper, we check which species of mites are carried byMonochamus sartor(Fabricius, 1787) in the largest natural forest complex in the North European Plain – The Białowieża Primeval Forest. Individuals of the species were collected in June and July 2012 with 64 intercept traps. In the context of the previous studies on phoresy of mites on the bark beetleIps typographus(Linnaeus, 1978) in Białowieża Primeval Forest, we conclude that the process of colonization of decaying wood by diverse species of insects entails increase in mite species diversity in this habitat (merocenosis). Our research indicates that mites travel on elytra and pronota ofM. sartor; however, dimensions (width and length) of these parts of body as well as the sex of the beetle are not significant for phoretic deutonymphs. [ABSTRACT FROM PUBLISHER]