This book provides the fi rst comprehensive review of the fauna of alien terrestrial arthropods t... more This book provides the fi rst comprehensive review of the fauna of alien terrestrial arthropods that have colonized the European continent and its associated islands. Directly ensuing from the DAISIE project, this is the result of the joint work of 89 authors from 27 different European countries. The book summarizes present knowledge of the arthropod invasion process, from temporal trends and biogeographic patterns, to pathways and vectors, invaded habitats, and ecological and economical impacts. A total of 1590 species alien to Europe, including crustaceans, myriapods, mites, spiders, and insects, are listed in two volumes and 21 separate chapters that detail the different taxonomic groups. For each species, all key information - feeding regime, date and country of fi rst record in Europe, invaded countries, invaded habitats, plant or animal host - is supplied. More detailed factsheets are provided for the 80 species considered to be most representative of the different pathways of...
Invasive non-native xylophagous longhorn, bark and jewel beetles are a serious threat to the bios... more Invasive non-native xylophagous longhorn, bark and jewel beetles are a serious threat to the biosecurity of urban, rural and forest trees, causing long-term damage and tree mortality. This has major impacts on pest and tree management as well as ecosystem services provide by trees. These beetles arrive in various forms of timber including logs, lumber, wood packaging, pallets and live trees for planting. Hence, early detection at or close to points of entry is therefore of paramount importance for the implementation and success of eradicating an invasive species. This project aimed to advance previous studies (Rassati <em>et al</em>., 2014; 2015) that demonstrated multi-funnel traps baited with multi-lures could be used to monitor for invasive beetles at points of entry of imported wood, but focusing primarily on longhorn beetles (Cerambycidae). The traps and lures currently available for surveillance of invasive xylophagous beetles were reviewed (Down and Audsley, 2017)...
The association between indirect environmental cues that modulate insect diapause and the actual ... more The association between indirect environmental cues that modulate insect diapause and the actual stressors is by no means granted when a species encounters new environments. The box tree moth, Cydalima perspectalis, is an Asian pest whose rapid invasion in Europe causes considerable economic and ecological impacts. Larvae enter a winter diapause induced by the photoperiod in both native and invaded ranges, but factors that trigger the return to an active phase are still unknown. Yet, identifying them is crucial to understand how diapause end synchronizes with the end of the winter stress encountered in Europe. To test whether activity resumption is regulated by thermal and/or photoperiodic thresholds, or additive effects between these factors often involved in diapause termination, diapausing caterpillars from an invaded area were exposed to crossed treatments at the laboratory. The evolution of diapause rate was monitored over time and compared to that of nearby field sites invaded...
Currently, two cupressaceae ecosystems threatened forest in Morocco; the thuriferous juniper and ... more Currently, two cupressaceae ecosystems threatened forest in Morocco; the thuriferous juniper and the cypress of the high Atlas, are very unsettled with almost absent undergrowth, an eroded soil, and regeneration greatly reduced. Added to the impact of pest mites and insects specialized in the exploitation of cones and seed. The present study aimed to 1) establish an inventory of the insect fauna associated with cones and seeds of two conifers 2) to measure its impact on the potential regeneration 3) clarify the relationship between phenology and pest host plant. For this, we selected several sites within the natural range of the thuriferous juniper and the cypress of the high Atlas. For the thuriferous juniper the selected sites included others species of Juniperus in order to clarify whether pest species could go from one to another, and what were the possible differences between the populations of pests present in each species. For the Cupressus atlantica, it has also sought to collect cones of Cupressus sempervirens to monitor wildlife trade possible between these species. On each site, crops of cones were conducted in late May. The percentage of cones attacked by insects and mites has been estimated, and then the seeds were extracted to be radiographed to estimate the potential for viable seeds. In addition, for the Cypress, a more detailed study was conducted on the seeds of such bugs Orsillus to compare their response to the two species of cypress. Within these pests we noted the presence of a single specific species of seed of Juniperus thurifera (Megastigmus thuriferana). This is a spermatophagous (according to the classification established by Turgeon et al. 1994). While Trisetacus quadrisetus, second spermatophagous species was identified in the other two Juniperus: J. oxycedrus and J. phoenicea. For the four species conospermatophagous only Argyresthia reticulata is specific of thuriferous juniper in Morocco. Regarding the impact of these pests, we should note the importance of attack seeds by insects and mites, including Trisetacus quadrisetus, Pammene oxycedrana, Argyresthia reticulata. These results confirm those of other previous work on the role of mites and insects in reducing the stock of seeds can germinate (El Alaoui El Fels 1999; El Alaoui El Fels & Roques 2006). For Atlas cypress, one can note the presence of the native species Megastigmus atlanticus(spermatophagous species, according to the classification of Turgeon et al. 1994), with the other species subservient evergreen cypress especially in the edge Mediterranean (Guido et al. 1995; Bouaziz & Chakali 1997; El Alaoui El Fels 1999; Roques et al. 1999). For damage, seeds Atlas cypress are the most attacked by pests. However, laboratory experiments conducted on the choice of Orsillus depressus over two cypress cones show no significant difference.
In the subalpine forest ecosystems of the French Alps, European larch trees (Larix decidua Mill.)... more In the subalpine forest ecosystems of the French Alps, European larch trees (Larix decidua Mill.) are periodically affected by outbreaks of a defoliating insect, the larch budmoth (Zeiraphera griseana (Hübner, 1799); LBM). To assess the long-term dynamics of LBM populations, we propose a spatiotemporal analysis of a long outbreak chronology reconstruction for the entire French Alps covering the period 1414–2009. This chronology was obtained by analyzing tree ring width (TRW) chronologies collected from 44 larch populations. The evidence of a latitudinal gradient in LBM is an original result that we have related to the “travelling waves” and “epicenter” theory. Wavelet analyses revealed a strong explicit continuous signal for periodicities of 4, 8, and 16 years throughout the entire 1500–2003 time series, except for a loss of power from 1690 to 1790 and since the early 1980s. We hypothesize that these abrupt changes could reflect a physiological response of LBM to past climatic varia...
Substantial progress has been made in understanding how pathways underlie and mediate biological ... more Substantial progress has been made in understanding how pathways underlie and mediate biological invasions. Yet, key features of their role in invasions remain poorly understood, available knowledge is widely scattered, and major frontiers in research and management are insufficiently characterized. We review the state of the art, highlight recent advances, identify pitfalls and constraints, and discuss major challenges in four broad fields of pathway research and management: pathway classification, application of pathway information, management response, and management impact. We present approaches to describe and quantify pathway attributes (e.g. spatio-temporal changes, proxies of introduction effort, environmental and socioeconomic contexts) and how they interact with species traits and regional characteristics. We also provide recommendations for a research agenda with particular focus on emerging (or neglected) research questions, and present new analytical tools in the context of pathway research and management.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Background: Intensification of world trade is responsible for an increase in the number of alien ... more Background: Intensification of world trade is responsible for an increase in the number of alien species introductions. Human-mediated dispersal promotes not only introductions but also expansion of the species distribution via long-distance dispersal. Thus, understanding the role of anthropogenic pathways in the spread of invading species has become one of the most important challenges nowadays. Methodology/Principal Findings: We analysed the invasion pattern of the pinewood nematode in China based on invasion data from 1982 to 2005 and monitoring data on 7 locations over 15 years. Short distance spread mediated by long-horned beetles was estimated at 7.5 km per year. Infested sites located further away represented more than 90% of observations and the mean long distance spread was estimated at 111-339 km. Railways, river ports, and lakes had significant effects on the spread pattern. Human population density levels explained 87% of the variation in the invasion probability (P,0.05). Since 2001, the number of new records of the nematode was multiplied by a factor of 5 and the spread distance by a factor of 2. We combined a diffusion model to describe the short distance spread with a stochastic, individual based model to describe the long distance jumps. This combined model generated an error of only 13% when used to predict the presence of the nematode. Under two climate scenarios (stable climate or moderate warming), projections of the invasion probability suggest that this pest could expand its distribution 40-55% by 2025. Conclusions/Significance: This study provides evidence that human-induced dispersal plays a fundamental role in the spread of the pinewood nematode, and appropriate control measures should be taken to stop or slow its expansion. This model can be applied to Europe, where the nematode had been introduced later, and is currently expanding its distribution. Similar models could also be derived for other species that could be accidentally transported by humans.
Phytophagous insects provide useful models for the study of ecological speciation. Much attention... more Phytophagous insects provide useful models for the study of ecological speciation. Much attention has been paid to host shifts, whereas situations where closely related lineages of insects use the same plant during different time periods have been relatively neglected in previous studies of insect diversification. Flies of the genus Strobilomyia are major pests of conifers in Eurasia and North America. They are specialized feeders in cones and seeds of Abies (fir), Larix (larch) ,and Picea (spruce). This close association is accompanied by a large number of sympatric Strobilomyia species coexisting within each tree genus. We constructed a molecular phylogeny with a 1320 base-pair fragment of mitochondrial DNA that demonstrated contrasting patterns of speciation in larch cone flies, as opposed to spruce and fir cone flies; this despite their comparable geographic distributions and similar resource quality of the host. Species diversity is the highest on larch, and speciation is primarily driven by within-host phenological shifts, followed by allopatric speciation during geographical expansion. By contrast, fewer species exploit spruce and fir, and within-host phenological shifts did not occur. This study illustrates within-host adaptive radiation through phenological shifts, a neglected mode of sympatric speciation.
The mitochondrial genome of Bactrocera cucurbitae, a representative of the Tephritid family, was ... more The mitochondrial genome of Bactrocera cucurbitae, a representative of the Tephritid family, was completely sequenced for the first time. The B. cucurbitae genome is a double-stranded circular molecule of 15,825 bp long, including the entire set of the 37 genes. The 72.9% A+T content and 0.047 AT-skew are within the range of the known dipteran genomes. Comparative analyses showed that dipteran mitochondrial protein-coding genes present complex evolutionary patterns. Some of the codon families were strongly biased towards J-strand. The mitochondrial ATP8 of B. cucurbitae exhibited a faster substitution rate than other genes. Cox1 is the slowest evolving protein and could be considered as a potential phylogenetic marker.
Surveillance using attractants for invasive species can allow early detection of new incursions a... more Surveillance using attractants for invasive species can allow early detection of new incursions and provide decision support to response programs. Simultaneous trapping for multiple species, by baiting traps with several lures, is expected to increase the number of species that can be targeted in surveillance programs and improve the cost-effectiveness without affecting surveillance coverage. We tested this hypothesis by choosing four potential forest and urban lepidopteran pest species that are present in Europe but not yet in New Zealand and many other countries. We deployed traps in central and southern Europe with single lures or all possible species combinations (up to four lures per trap). There was only limited interference, apparently due to trap saturation, but no evidence for interspecific repellency among lures for gypsy moth, Lymantria dispar, fall webworm, Hyphantria cunea, pine processionary moth, Thaumetopoea pityocampa, and pine shoot moth, Rhyacionia buoliana. To assess what factors may be important in species compatibility/suitability for multiple-species trapping, we combined our results with those of previous studies conducted by the United States Department of Agriculture. For 75 combinations of pheromones, tested singly or in combination, 19 % showed no effect on trap catch for any of the species tested. In the other cases, either one or both species showed a reduction in trap catch. However, few lure combinations caused complete or nearly complete suppression. For most combinations, catches were still sufficiently high for detection purposes. Species from the same superfamily exhibited more interference than more distantly related species. Together, these results suggest that there are opportunities to improve the range of exotic pests under surveillance, at little additional cost, by multiple-species trapping for which compatibility has been demonstrated.
Effects of recent climate change have already been detected in many species, and, in particular, ... more Effects of recent climate change have already been detected in many species, and, in particular, in insects. The present paper reviews the key impacts of global warming on insect development and dispersal. The effects of climate change appear to be much more complex than a simple linear response to an average increase in temperature. They can differ between seasons and bioclimatic regions. Earlier flight periods, enhanced winter survival and acceleration of development rates are the major insect responses. Differential response of insects and hosts to warming up might also lead to disruption of their phenological synchrony, but adaptive genetic processes are likely to quickly restore this synchrony. In a number of cases, warming results in removing or relocating the barriers that limit present species' ranges. It is also likely to facilitate the establishment and spread of invasive alien species. Finally, knowledge gaps are identified and future research interests are suggested.
Recent climate change is known to affect the distribution of a number of insect species, resultin... more Recent climate change is known to affect the distribution of a number of insect species, resulting in a modification of their range boundaries. In newly colonized areas, novel interactions become apparent between expanding and endemic species sharing the same host. The pine processionary moth is a highly damaging pine defoliator, extending its range northwards and upwards in response to winter warming. Its expansion in the Alps has result-resulted in an invasion into the range of the Spanish moon moth, a red listed species developing on Scots pine. Pine processionary moth larvae develop during winter, preceding those of the moon moth, which hatch in late spring. Using pine trees planted in a clonal design, we experimentally tested the effect of previous winter defoliation by pine processionary moth larvae upon the survival and development of moon moth larvae. Feeding on foliage of heavily defoliated trees (>50%) resulted in a significant increase in the development time of moon moth larvae and a decrease in relative growth rate compared to feeding on foliage of undefoliated trees. Dry weight of pupae also decreased when larvae were fed with foliage of defoliated trees, and might, therefore, affect imago perfor-decreased when larvae were fed with foliage of defoliated trees, and might, therefore, affect imago performances. �owever, lower defoliation degrees did not result in signifi cant differences in larval performances com� �owever, lower defoliation degrees did not result in significant differences in larval performances compared to the control. Because a high degree of defoliation by pine processionary moth is to be expected during the colonization phase, its arrival in subalpine pine stands might affect the populations of the endangered moon moth
Classical biological control is often advocated as a tool for managing invasive species. However,... more Classical biological control is often advocated as a tool for managing invasive species. However, accurate evaluations of parasitoid species complexes and assessment of host specificity are impeded by the lack of morphological variation. Here, we study the possibility of host races/species within the eulophid wasp Pediobius saulius, a pupal generalist parasitoid that parasitize the highly invasive horse-chestnut leaf-mining moth Cameraria ohridella. We analysed the population genetic structure, host associations and phylogeographic patterns of P. saulius in Europe using the COI mitochondrial gene. This marker strongly supports a division into at least five highly differentiated parasitoid complexes, within two of which clades with differing degrees of host specialization were found: a Balkan clade that mainly (but not only) attacks C. ohridella and a more generalist European group that attacks many hosts, including C. ohridella. The divergence in COI (up to 7.6%) suggests the existence of cryptic species, although this is neither confirmed by nuclear divergence nor morphology. We do not find evidence of host tracking. The higher parasitism rates observed in the Balkans and the scarcity of the Balkan-Cameraria haplotypes out of the Balkans open the possibility of using these Balkan haplotypes as biological control agents of C. ohridella elsewhere in Europe.
Information relevant to invasion processes and invasive alien insect species management in Centra... more Information relevant to invasion processes and invasive alien insect species management in Central Europe was extracted from two databases: a compilation of two inventories of alien insects in Austria and Switzerland, and a list of interceptions of non-indigenous plant pests in Europe gathered by the European and Mediterranean Plant Protection Organisation (EPPO) for the period 1995–2004. For one-third of the insects established in Switzerland and Austria, the region of origin is unclear. Others come mainly from North America, Asia and the Mediterranean region. Among the intercepted insects, 40% were associated with commodities from Asia, 32% from Europe and only 2% from North America. Sternorrhyncha, Coleoptera and Psocoptera were particularly well represented in the alien fauna compared to the native fauna. In the interception database, Sternorrhyncha were also well represented but Diptera accounted for the highest number of records. Sap feeders and detritivores were the dominant ...
This book provides the fi rst comprehensive review of the fauna of alien terrestrial arthropods t... more This book provides the fi rst comprehensive review of the fauna of alien terrestrial arthropods that have colonized the European continent and its associated islands. Directly ensuing from the DAISIE project, this is the result of the joint work of 89 authors from 27 different European countries. The book summarizes present knowledge of the arthropod invasion process, from temporal trends and biogeographic patterns, to pathways and vectors, invaded habitats, and ecological and economical impacts. A total of 1590 species alien to Europe, including crustaceans, myriapods, mites, spiders, and insects, are listed in two volumes and 21 separate chapters that detail the different taxonomic groups. For each species, all key information - feeding regime, date and country of fi rst record in Europe, invaded countries, invaded habitats, plant or animal host - is supplied. More detailed factsheets are provided for the 80 species considered to be most representative of the different pathways of...
Pitch canker, caused by the pathogen Fusarium circinatum, is a serious disease of pines, Pinus sp... more Pitch canker, caused by the pathogen Fusarium circinatum, is a serious disease of pines, Pinus species. It is a threat to natural and planted pine forests, and to date it has invaded countries across five continents. Pine-feeding insects can play a key role in the epidemiology of the disease, as wounding agents allowing pathogen access or as vectors transmitting the pathogen from infected to healthy trees. We reviewed the role of insects in the epidemiology of pitch canker worldwide and assessed which insects are present in New Zealand that may act as wounding agents or vectors to determine whether pathogen invasion could adversely affect Pinus radiata plantation forests and urban trees. We also evaluated whether cone or seed insects of pines could be introduced as biological control agents of invasive Pinus contorta and how this may affect the impact of a potential F. circinatum invasion. As there are no native pines or other Pinaceae in New Zealand, there are only few pine insects, mainly accidental introductions. None of the insects recorded on pines in New Zealand is likely to be a vector, suggesting low disease risk. Of six potentially suitable biocontrol candidates, the European pine cone weevil Pissodes validirostris is the most promising regarding host specificity and impact on seed production, but there is uncertainty about its ability to act as vector of F. circinatum. Our methodology to review and evaluate the vector potential of pine associates can be used as a generic framework to assess the potential impacts of F. circinatum invasion.
This book provides the fi rst comprehensive review of the fauna of alien terrestrial arthropods t... more This book provides the fi rst comprehensive review of the fauna of alien terrestrial arthropods that have colonized the European continent and its associated islands. Directly ensuing from the DAISIE project, this is the result of the joint work of 89 authors from 27 different European countries. The book summarizes present knowledge of the arthropod invasion process, from temporal trends and biogeographic patterns, to pathways and vectors, invaded habitats, and ecological and economical impacts. A total of 1590 species alien to Europe, including crustaceans, myriapods, mites, spiders, and insects, are listed in two volumes and 21 separate chapters that detail the different taxonomic groups. For each species, all key information - feeding regime, date and country of fi rst record in Europe, invaded countries, invaded habitats, plant or animal host - is supplied. More detailed factsheets are provided for the 80 species considered to be most representative of the different pathways of...
Invasive non-native xylophagous longhorn, bark and jewel beetles are a serious threat to the bios... more Invasive non-native xylophagous longhorn, bark and jewel beetles are a serious threat to the biosecurity of urban, rural and forest trees, causing long-term damage and tree mortality. This has major impacts on pest and tree management as well as ecosystem services provide by trees. These beetles arrive in various forms of timber including logs, lumber, wood packaging, pallets and live trees for planting. Hence, early detection at or close to points of entry is therefore of paramount importance for the implementation and success of eradicating an invasive species. This project aimed to advance previous studies (Rassati <em>et al</em>., 2014; 2015) that demonstrated multi-funnel traps baited with multi-lures could be used to monitor for invasive beetles at points of entry of imported wood, but focusing primarily on longhorn beetles (Cerambycidae). The traps and lures currently available for surveillance of invasive xylophagous beetles were reviewed (Down and Audsley, 2017)...
The association between indirect environmental cues that modulate insect diapause and the actual ... more The association between indirect environmental cues that modulate insect diapause and the actual stressors is by no means granted when a species encounters new environments. The box tree moth, Cydalima perspectalis, is an Asian pest whose rapid invasion in Europe causes considerable economic and ecological impacts. Larvae enter a winter diapause induced by the photoperiod in both native and invaded ranges, but factors that trigger the return to an active phase are still unknown. Yet, identifying them is crucial to understand how diapause end synchronizes with the end of the winter stress encountered in Europe. To test whether activity resumption is regulated by thermal and/or photoperiodic thresholds, or additive effects between these factors often involved in diapause termination, diapausing caterpillars from an invaded area were exposed to crossed treatments at the laboratory. The evolution of diapause rate was monitored over time and compared to that of nearby field sites invaded...
Currently, two cupressaceae ecosystems threatened forest in Morocco; the thuriferous juniper and ... more Currently, two cupressaceae ecosystems threatened forest in Morocco; the thuriferous juniper and the cypress of the high Atlas, are very unsettled with almost absent undergrowth, an eroded soil, and regeneration greatly reduced. Added to the impact of pest mites and insects specialized in the exploitation of cones and seed. The present study aimed to 1) establish an inventory of the insect fauna associated with cones and seeds of two conifers 2) to measure its impact on the potential regeneration 3) clarify the relationship between phenology and pest host plant. For this, we selected several sites within the natural range of the thuriferous juniper and the cypress of the high Atlas. For the thuriferous juniper the selected sites included others species of Juniperus in order to clarify whether pest species could go from one to another, and what were the possible differences between the populations of pests present in each species. For the Cupressus atlantica, it has also sought to collect cones of Cupressus sempervirens to monitor wildlife trade possible between these species. On each site, crops of cones were conducted in late May. The percentage of cones attacked by insects and mites has been estimated, and then the seeds were extracted to be radiographed to estimate the potential for viable seeds. In addition, for the Cypress, a more detailed study was conducted on the seeds of such bugs Orsillus to compare their response to the two species of cypress. Within these pests we noted the presence of a single specific species of seed of Juniperus thurifera (Megastigmus thuriferana). This is a spermatophagous (according to the classification established by Turgeon et al. 1994). While Trisetacus quadrisetus, second spermatophagous species was identified in the other two Juniperus: J. oxycedrus and J. phoenicea. For the four species conospermatophagous only Argyresthia reticulata is specific of thuriferous juniper in Morocco. Regarding the impact of these pests, we should note the importance of attack seeds by insects and mites, including Trisetacus quadrisetus, Pammene oxycedrana, Argyresthia reticulata. These results confirm those of other previous work on the role of mites and insects in reducing the stock of seeds can germinate (El Alaoui El Fels 1999; El Alaoui El Fels & Roques 2006). For Atlas cypress, one can note the presence of the native species Megastigmus atlanticus(spermatophagous species, according to the classification of Turgeon et al. 1994), with the other species subservient evergreen cypress especially in the edge Mediterranean (Guido et al. 1995; Bouaziz & Chakali 1997; El Alaoui El Fels 1999; Roques et al. 1999). For damage, seeds Atlas cypress are the most attacked by pests. However, laboratory experiments conducted on the choice of Orsillus depressus over two cypress cones show no significant difference.
In the subalpine forest ecosystems of the French Alps, European larch trees (Larix decidua Mill.)... more In the subalpine forest ecosystems of the French Alps, European larch trees (Larix decidua Mill.) are periodically affected by outbreaks of a defoliating insect, the larch budmoth (Zeiraphera griseana (Hübner, 1799); LBM). To assess the long-term dynamics of LBM populations, we propose a spatiotemporal analysis of a long outbreak chronology reconstruction for the entire French Alps covering the period 1414–2009. This chronology was obtained by analyzing tree ring width (TRW) chronologies collected from 44 larch populations. The evidence of a latitudinal gradient in LBM is an original result that we have related to the “travelling waves” and “epicenter” theory. Wavelet analyses revealed a strong explicit continuous signal for periodicities of 4, 8, and 16 years throughout the entire 1500–2003 time series, except for a loss of power from 1690 to 1790 and since the early 1980s. We hypothesize that these abrupt changes could reflect a physiological response of LBM to past climatic varia...
Substantial progress has been made in understanding how pathways underlie and mediate biological ... more Substantial progress has been made in understanding how pathways underlie and mediate biological invasions. Yet, key features of their role in invasions remain poorly understood, available knowledge is widely scattered, and major frontiers in research and management are insufficiently characterized. We review the state of the art, highlight recent advances, identify pitfalls and constraints, and discuss major challenges in four broad fields of pathway research and management: pathway classification, application of pathway information, management response, and management impact. We present approaches to describe and quantify pathway attributes (e.g. spatio-temporal changes, proxies of introduction effort, environmental and socioeconomic contexts) and how they interact with species traits and regional characteristics. We also provide recommendations for a research agenda with particular focus on emerging (or neglected) research questions, and present new analytical tools in the context of pathway research and management.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Background: Intensification of world trade is responsible for an increase in the number of alien ... more Background: Intensification of world trade is responsible for an increase in the number of alien species introductions. Human-mediated dispersal promotes not only introductions but also expansion of the species distribution via long-distance dispersal. Thus, understanding the role of anthropogenic pathways in the spread of invading species has become one of the most important challenges nowadays. Methodology/Principal Findings: We analysed the invasion pattern of the pinewood nematode in China based on invasion data from 1982 to 2005 and monitoring data on 7 locations over 15 years. Short distance spread mediated by long-horned beetles was estimated at 7.5 km per year. Infested sites located further away represented more than 90% of observations and the mean long distance spread was estimated at 111-339 km. Railways, river ports, and lakes had significant effects on the spread pattern. Human population density levels explained 87% of the variation in the invasion probability (P,0.05). Since 2001, the number of new records of the nematode was multiplied by a factor of 5 and the spread distance by a factor of 2. We combined a diffusion model to describe the short distance spread with a stochastic, individual based model to describe the long distance jumps. This combined model generated an error of only 13% when used to predict the presence of the nematode. Under two climate scenarios (stable climate or moderate warming), projections of the invasion probability suggest that this pest could expand its distribution 40-55% by 2025. Conclusions/Significance: This study provides evidence that human-induced dispersal plays a fundamental role in the spread of the pinewood nematode, and appropriate control measures should be taken to stop or slow its expansion. This model can be applied to Europe, where the nematode had been introduced later, and is currently expanding its distribution. Similar models could also be derived for other species that could be accidentally transported by humans.
Phytophagous insects provide useful models for the study of ecological speciation. Much attention... more Phytophagous insects provide useful models for the study of ecological speciation. Much attention has been paid to host shifts, whereas situations where closely related lineages of insects use the same plant during different time periods have been relatively neglected in previous studies of insect diversification. Flies of the genus Strobilomyia are major pests of conifers in Eurasia and North America. They are specialized feeders in cones and seeds of Abies (fir), Larix (larch) ,and Picea (spruce). This close association is accompanied by a large number of sympatric Strobilomyia species coexisting within each tree genus. We constructed a molecular phylogeny with a 1320 base-pair fragment of mitochondrial DNA that demonstrated contrasting patterns of speciation in larch cone flies, as opposed to spruce and fir cone flies; this despite their comparable geographic distributions and similar resource quality of the host. Species diversity is the highest on larch, and speciation is primarily driven by within-host phenological shifts, followed by allopatric speciation during geographical expansion. By contrast, fewer species exploit spruce and fir, and within-host phenological shifts did not occur. This study illustrates within-host adaptive radiation through phenological shifts, a neglected mode of sympatric speciation.
The mitochondrial genome of Bactrocera cucurbitae, a representative of the Tephritid family, was ... more The mitochondrial genome of Bactrocera cucurbitae, a representative of the Tephritid family, was completely sequenced for the first time. The B. cucurbitae genome is a double-stranded circular molecule of 15,825 bp long, including the entire set of the 37 genes. The 72.9% A+T content and 0.047 AT-skew are within the range of the known dipteran genomes. Comparative analyses showed that dipteran mitochondrial protein-coding genes present complex evolutionary patterns. Some of the codon families were strongly biased towards J-strand. The mitochondrial ATP8 of B. cucurbitae exhibited a faster substitution rate than other genes. Cox1 is the slowest evolving protein and could be considered as a potential phylogenetic marker.
Surveillance using attractants for invasive species can allow early detection of new incursions a... more Surveillance using attractants for invasive species can allow early detection of new incursions and provide decision support to response programs. Simultaneous trapping for multiple species, by baiting traps with several lures, is expected to increase the number of species that can be targeted in surveillance programs and improve the cost-effectiveness without affecting surveillance coverage. We tested this hypothesis by choosing four potential forest and urban lepidopteran pest species that are present in Europe but not yet in New Zealand and many other countries. We deployed traps in central and southern Europe with single lures or all possible species combinations (up to four lures per trap). There was only limited interference, apparently due to trap saturation, but no evidence for interspecific repellency among lures for gypsy moth, Lymantria dispar, fall webworm, Hyphantria cunea, pine processionary moth, Thaumetopoea pityocampa, and pine shoot moth, Rhyacionia buoliana. To assess what factors may be important in species compatibility/suitability for multiple-species trapping, we combined our results with those of previous studies conducted by the United States Department of Agriculture. For 75 combinations of pheromones, tested singly or in combination, 19 % showed no effect on trap catch for any of the species tested. In the other cases, either one or both species showed a reduction in trap catch. However, few lure combinations caused complete or nearly complete suppression. For most combinations, catches were still sufficiently high for detection purposes. Species from the same superfamily exhibited more interference than more distantly related species. Together, these results suggest that there are opportunities to improve the range of exotic pests under surveillance, at little additional cost, by multiple-species trapping for which compatibility has been demonstrated.
Effects of recent climate change have already been detected in many species, and, in particular, ... more Effects of recent climate change have already been detected in many species, and, in particular, in insects. The present paper reviews the key impacts of global warming on insect development and dispersal. The effects of climate change appear to be much more complex than a simple linear response to an average increase in temperature. They can differ between seasons and bioclimatic regions. Earlier flight periods, enhanced winter survival and acceleration of development rates are the major insect responses. Differential response of insects and hosts to warming up might also lead to disruption of their phenological synchrony, but adaptive genetic processes are likely to quickly restore this synchrony. In a number of cases, warming results in removing or relocating the barriers that limit present species' ranges. It is also likely to facilitate the establishment and spread of invasive alien species. Finally, knowledge gaps are identified and future research interests are suggested.
Recent climate change is known to affect the distribution of a number of insect species, resultin... more Recent climate change is known to affect the distribution of a number of insect species, resulting in a modification of their range boundaries. In newly colonized areas, novel interactions become apparent between expanding and endemic species sharing the same host. The pine processionary moth is a highly damaging pine defoliator, extending its range northwards and upwards in response to winter warming. Its expansion in the Alps has result-resulted in an invasion into the range of the Spanish moon moth, a red listed species developing on Scots pine. Pine processionary moth larvae develop during winter, preceding those of the moon moth, which hatch in late spring. Using pine trees planted in a clonal design, we experimentally tested the effect of previous winter defoliation by pine processionary moth larvae upon the survival and development of moon moth larvae. Feeding on foliage of heavily defoliated trees (>50%) resulted in a significant increase in the development time of moon moth larvae and a decrease in relative growth rate compared to feeding on foliage of undefoliated trees. Dry weight of pupae also decreased when larvae were fed with foliage of defoliated trees, and might, therefore, affect imago perfor-decreased when larvae were fed with foliage of defoliated trees, and might, therefore, affect imago performances. �owever, lower defoliation degrees did not result in signifi cant differences in larval performances com� �owever, lower defoliation degrees did not result in significant differences in larval performances compared to the control. Because a high degree of defoliation by pine processionary moth is to be expected during the colonization phase, its arrival in subalpine pine stands might affect the populations of the endangered moon moth
Classical biological control is often advocated as a tool for managing invasive species. However,... more Classical biological control is often advocated as a tool for managing invasive species. However, accurate evaluations of parasitoid species complexes and assessment of host specificity are impeded by the lack of morphological variation. Here, we study the possibility of host races/species within the eulophid wasp Pediobius saulius, a pupal generalist parasitoid that parasitize the highly invasive horse-chestnut leaf-mining moth Cameraria ohridella. We analysed the population genetic structure, host associations and phylogeographic patterns of P. saulius in Europe using the COI mitochondrial gene. This marker strongly supports a division into at least five highly differentiated parasitoid complexes, within two of which clades with differing degrees of host specialization were found: a Balkan clade that mainly (but not only) attacks C. ohridella and a more generalist European group that attacks many hosts, including C. ohridella. The divergence in COI (up to 7.6%) suggests the existence of cryptic species, although this is neither confirmed by nuclear divergence nor morphology. We do not find evidence of host tracking. The higher parasitism rates observed in the Balkans and the scarcity of the Balkan-Cameraria haplotypes out of the Balkans open the possibility of using these Balkan haplotypes as biological control agents of C. ohridella elsewhere in Europe.
Information relevant to invasion processes and invasive alien insect species management in Centra... more Information relevant to invasion processes and invasive alien insect species management in Central Europe was extracted from two databases: a compilation of two inventories of alien insects in Austria and Switzerland, and a list of interceptions of non-indigenous plant pests in Europe gathered by the European and Mediterranean Plant Protection Organisation (EPPO) for the period 1995–2004. For one-third of the insects established in Switzerland and Austria, the region of origin is unclear. Others come mainly from North America, Asia and the Mediterranean region. Among the intercepted insects, 40% were associated with commodities from Asia, 32% from Europe and only 2% from North America. Sternorrhyncha, Coleoptera and Psocoptera were particularly well represented in the alien fauna compared to the native fauna. In the interception database, Sternorrhyncha were also well represented but Diptera accounted for the highest number of records. Sap feeders and detritivores were the dominant ...
This book provides the fi rst comprehensive review of the fauna of alien terrestrial arthropods t... more This book provides the fi rst comprehensive review of the fauna of alien terrestrial arthropods that have colonized the European continent and its associated islands. Directly ensuing from the DAISIE project, this is the result of the joint work of 89 authors from 27 different European countries. The book summarizes present knowledge of the arthropod invasion process, from temporal trends and biogeographic patterns, to pathways and vectors, invaded habitats, and ecological and economical impacts. A total of 1590 species alien to Europe, including crustaceans, myriapods, mites, spiders, and insects, are listed in two volumes and 21 separate chapters that detail the different taxonomic groups. For each species, all key information - feeding regime, date and country of fi rst record in Europe, invaded countries, invaded habitats, plant or animal host - is supplied. More detailed factsheets are provided for the 80 species considered to be most representative of the different pathways of...
Pitch canker, caused by the pathogen Fusarium circinatum, is a serious disease of pines, Pinus sp... more Pitch canker, caused by the pathogen Fusarium circinatum, is a serious disease of pines, Pinus species. It is a threat to natural and planted pine forests, and to date it has invaded countries across five continents. Pine-feeding insects can play a key role in the epidemiology of the disease, as wounding agents allowing pathogen access or as vectors transmitting the pathogen from infected to healthy trees. We reviewed the role of insects in the epidemiology of pitch canker worldwide and assessed which insects are present in New Zealand that may act as wounding agents or vectors to determine whether pathogen invasion could adversely affect Pinus radiata plantation forests and urban trees. We also evaluated whether cone or seed insects of pines could be introduced as biological control agents of invasive Pinus contorta and how this may affect the impact of a potential F. circinatum invasion. As there are no native pines or other Pinaceae in New Zealand, there are only few pine insects, mainly accidental introductions. None of the insects recorded on pines in New Zealand is likely to be a vector, suggesting low disease risk. Of six potentially suitable biocontrol candidates, the European pine cone weevil Pissodes validirostris is the most promising regarding host specificity and impact on seed production, but there is uncertainty about its ability to act as vector of F. circinatum. Our methodology to review and evaluate the vector potential of pine associates can be used as a generic framework to assess the potential impacts of F. circinatum invasion.
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