Trapping strategy for Monochamus sutor and Monochamus galloprovincialis: potential vectors of the pine wood nematode in Scandinavia

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Taxonomy and phylogeny of European Monochamus species: first molecular and karyological data

The worldwide distributed genus Monochamus Megerle, 1821 (Coleoptera Cerambicydae) comprises beetles that may become pests of economic importance in conifer stands in the Nearctic and Palearctic Regions. Besides direct damage due to the larval tunnelling habits, they have also been recognized as main vectors of the phytoparasitic nematode Bursaphelenchus xylophilus (Steiner & Buhrer, 1934) (Nematoda Aphelenchoididae). We analysed the complete mitochondrial cytochrome oxidase I gene and a fragment of the small subunit RNA gene sequences (1536 base pairs) in the five European species. These are: Monochamus galloprovincialis (Olivier, 1795), morphologically distinguished in two subspecies M. galloprovincialis galloprovincialis (Olivier, 1795) and M. galloprovincialis pistor (Germar, 1818); Monochamus sutor (Linneus 1758); Monochamus saltuarius (Gebler 1830); Monochamus sartor (Fabricius, 1787) and Monochamus urussovi (Fischer, 1806). For appropriate comparisons, also the Asiatic Monochamus alternatus Hope, 1842 and a Japanese M. saltuarius sample have been analysed. Both genes show an absolute identity between the two subspecies of M. galloprovincialis and a strong affinity between M. sartor and M. urussovi: the morphological subdivisions of the former taxon in two subspecies and of the latter in two entities of specific level are therefore not supported genetically. On the other hand, the Italian and the Japanese samples of M. saltuarius always cluster together in all trees, and for the remaining taxa, no doubt about their rank of specific differentiation emerges from present analyses. From a phyletic point of view, tree topology indicates the Japanese M. alternatus as the most differentiated taxon and the Euroasiatic M. saltuarius as basal to all other strictly European entities. Chromosome analyses show that the diploid autosomal complement ranges from 18 in M. saltuarius to 20 in M. galloprovincialis, and 22 in M. sartor, but a XX–Xy_p sex determining system is shared by all analysed taxa. The M. saltuarius karyotype appears as the most primitive from which the others may be derived through Robertsonian fissions. Karyological data therefore agree with molecular analyses in indicating a basal position of Euroasiatic M. saltuarius with respect to the group of European Monochamus taxa; among these, M. galloprovincialis and M. sartor represent two clearly diverging evolutionary units. Furthermore, karyotype analyses substantiate molecular conclusions about the identity between M. galloprovincialis galloprovincialis and M. galloprovincialis pistor.     

Attractants for management of the pine sawyer beetle Monochamus sutor,a potential vector of Bursaphelenchus xylophilus

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.     

2‐(Undecyloxy)‐ethanol is a major component of the male‐produced aggregation pheromone of Monochamus sutor

The small white‐marmorated longicorn beetle, Monochamus sutor (L.) (Coleoptera: Cerambycidae), is widely distributed throughout Europe and Asia. It is a potential vector of the pine wood nematode, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle, the causal agent of the devastating pine wilt disease. Volatiles were collected from both male and female beetles after maturation feeding. In analyses of these collections using gas chromatography (GC) coupled to mass spectrometry, a single male‐specific compound was detected and identified as 2‐(undecyloxy)‐ethanol. In analyses by GC coupled to electroantennography the only consistent responses from both female and male antennae were to this compound. Trapping tests were carried out in Spain, Sweden, and China. 2‐(Undecyloxy)‐ethanol was attractive to both male and female M. sutor beetles. A blend of the bark beetle pheromones ipsenol, ipsdienol, and 2‐methyl‐3‐buten‐2‐ol was also attractive to both sexes in Spain and Sweden, and further increased the attractiveness of the 2‐(undecyloxy)‐ethanol. The host plant volatiles α‐pinene, 3‐carene, and ethanol were weakly attractive, if at all, in all three countries and did not significantly increase the attractiveness of the blend of 2‐(undecyloxy)‐ethanol and bark beetle pheromones. 2‐(Undecyloxy)‐ethanol is thus proposed to be the major, if not only, component of the male‐produced aggregation pheromone of M. sutor, and its role is discussed. This compound has been reported as a pheromone of several other Monochamus species and is another example of the parsimony that seems to exist among the pheromones of many of the Cerambycidae. Traps baited with 2‐(undecyloxy)‐ethanol and bark beetle pheromones should be useful for monitoring and control of pine wilt disease, should M. sutor be proven to be a vector of the nematode.     

Genetic diversity of Southern hemisphere blue mussels (Bivalvia: Mytilidae) and the identification of non‐indigenous taxa

The taxonomic and evolutionary affinities of Southern hemisphere smooth‐shelled blue mussels are unclear, with studies using different marker types having identified different relationships among various geographic regions. Using an existing and a new molecular assay, the present study builds on previous work to test the distribution of blue mussels native to and introduced to the Southern hemisphere. Populations of Mytilus were sampled from New Zealand, Australia, and Chile. The nuclear‐DNA marker Me 15/16 was used to identify the taxonomic status of 484 individuals. A new restriction fragment length polymorphism (RFLP) assay was used to identify the hemisphere of origin for a subset of Mytilus galloprovincialis. The Me15/16 marker identified 478 pure M. galloprovincialis from Southern hemisphere sites and six Mytilus edulis/M. galloprovincialis hybrids from the Auckland Islands (New Zealand) and Chile. A cytoplasmic RFLP identified Northern hemisphere M. galloprovincialis in almost every Southern hemisphere region. The presence of native M. galloprovincialis at high latitudes (up to 52°S) has implications for our understanding of environmentally induced selective constraints considered to determine species distributions. Widespread occurrence of invasive Northern hemisphere blue mussels in the Southern hemisphere is documented for the first time. Identification of inter‐specific hybrids (M. edulis × M. galloprovincialis) in Chile and in the Auckland Islands (subantarctic New Zealand) illustrates that environments ranging from international ports to remote protected locations are vulnerable to bioinvasion. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 898–909.     

Phylogeny and evolution of the South African genus Metalasia (Asteraceae–Gnaphalieae) inferred from molecular and morphological data

Metalasia is a genus in tribe Gnaphalieae (Asteraceae), endemic to South Africa and with its main distribution in the Cape Floristic Region. The genus comprises 57 species and, with a number of closely related genera, it constitutes the ‘Metalasia clade’. A species‐level phylogenetic analysis is presented, based on DNA sequences from two nuclear (internal and external transcribed spacer: ITS, ETS) and two plastid (psbA‐trnH, trnL‐trnF) regions together with morphological data. Analyses combining molecular and morphological data attempt not only to resolve species interrelationships, but also to detect patterns in character evolution. Phylogenetic analyses corroborate our earlier study and demonstrate that Metalasia is formed of two equally sized, well‐supported sister groups, one of which is characterized by papillose cypselas. The results differ greatly from earlier hypotheses based on morphology alone, as few morphological characters support the phylogenetic patterns obtained. The two clades of Metalasia do, however, appear to differ in distribution, corresponding to the different rainfall regimes of South Africa. Analyses show a few taxa to be problematic; one example is the widely distributed M. densa which appears to be an intricate species complex. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174 , 173–198.     

Dispersal capacity of Monochamus galloprovincialis,the European vector of the pine wood nematode,on flight mills

The pine wood nematode (Bursaphelenchus xylophilus), which causes the symptoms of pine wilt disease, is recognized worldwide as a major forest pest. It was introduced into Portugal in 1999. It is transmitted between trees almost exclusively by longhorn beetles of the genus Monochamus, including, in particular, M. galloprovincialis (Coleoptera: Cerambycidae) in maritime pine forests. Accurate estimates of the flight capacity of this insect vector are required if we are to understand and predict the spread of pine wilt disease in Europe. Using computer‐linked flight mills, we evaluated the distance flown, the flight probability and speed of M. galloprovincialis throughout adulthood and investigated the effects of age, sex and body weight on these flight performances, which are proxies for dispersal capacity. The within‐population variability of flight performance in M. galloprovincialis was high, with a mean distance of 16 km flown over the lifetime of the beetle. Age and body weight had a significant positive effect on flight capacity, but there was no difference in performance between males and females. These findings have important implications for managing the spread of the pine wood nematode in European forests.     

Phylogeographic analyses reveal distinct lineages of the liverworts Metzgeria furcata (L.) Dumort. and Metzgeria conjugata Lindb. (Metzgeriaceae) in Europe and North America

Seed plant genera often exhibit intercontinental disjunctions where different species are found on different continents. Many morphologically circumscribed bryophyte species exhibit similar disjunctions. We used nucleotide sequences from the plastid and nuclear genomes to test hypotheses of phylogeography within representatives of the genus Metzgeria: Metzgeria furcata, Metzgeria conjugata, and Metzgeria myriopoda. The first two species have sexual and asexual populations, exhibit disjunctions between North America and Europe, and have been split into separate species, numerous subspecies or varieties. The third species occurs in eastern North America but is not reported from Europe. Phylogenetic analyses resolved three distinct lineages within the morphologically defined species, M. furcata: one in North America, and two in Europe. Similarly, three morphologically cryptic clades of M. conjugata were resolved by the molecular data: northern North America, Europe, and south‐eastern North America. For both species, molecular divergence among taxa occurred in the absence of morphological change. In the case of M. myriopoda, all plants from eastern North America were both morphologically uniform and genetically homogeneous (although not identical). The present study provides significant insight into a plant group with complex taxonomy, and indicates that these liverwort taxa with wide distributions, extreme sex ratios, and continental disjunctions harbor cryptic lineages. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 745–756.     

Climate and refugial origin influence the mitochondrial lineage distribution of weasels (Mustela nivalis) in a phylogeographic suture zone

Overarching trends can be seen in European mammalian phylogeography, yet it is clear that species responded differently depending on adaptations to past environments. We built upon previous work on the phylogeography of weasels (Mustela nivalis) in Europe by using well‐preserved museum specimens from a proposed phylogeographic suture zone. The complete cytochrome b gene was amplified from 49 individuals from present‐day Poland and analyzed with previously published data on a European scale to identify glacial refugia and infer recolonization processes. Bayesian coalescent analysis revealed the importance of the Last Glacial Maximum and the Younger Dryas in the diversification of, and demographic changes in, identified mitochondrial lineages. Our analysis, in conjunction with the available fossil data, strongly points to a Carpathian origin for one of the lineages, and further highlights the importance of this region as a refugium for European mammals. Mustela nivalis originating from this refugium appear to have a selective advantage over M. nivalis from other lineages in certain environments in the suture zone in central Europe, with climate clearly influencing the distribution of mitochondrial DNA lineages. This has important implications not only for our understanding of how past climatic events shaped the genetic architecture of species, but also how they will respond to current and future climatic changes. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 57–69.     

Combining pheromone and kairomones for effective trapping of the pine sawyer beetle Monochamus galloprovincialis

Monochamus galloprovincialis (Olivier) (Coleoptera: Cerambycidae) is a secondary wood borer that acquired primordial importance since it was identified as the European vector of Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD). An effective trapping method is needed as a tool for managing this insect vector and allowing early detection of nematode transportation. Among effective attractants identified in recent years are the specific M. galloprovincialis aggregation pheromone, host pine kairomones such as α‐pinene and bark beetle kairomones like ipsenol and methyl‐butenol. The main objective of this study was to optimize the combination of these volatiles to improve lure attractiveness and specificity. Based on ten complementary field experiments, we found a pheromone dose‐response of trap catches. The best combination of attractants was the aggregation pheromone plus two bark beetle kairomones, ipsenol and methyl‐butenol. Addition of pine terpenes, such as α‐pinene, did not significantly improve M. galloprovincialis trap capture, but did increase catch of non target species, including natural enemies. The use of pine terpenes would be advisable only if priorizing to maximize removal of vectors. While this research has lead to the development a new, highly attractive commercial lure for mature pine sawyers, none of the tested blends were successful in attracting immature pine sawyer adults. Further investigation is needed to develop attractants for these beetles.     

Morphology and distribution of antennal sensilla in the pine wood nematode insect vectors Monochamus alternatus Hope and Monochamus saltuarius Gebler (Coleoptera: Cerambycidae)

As insect vectors of pine wood nematodes, Monochamus alternatus Hope and Monochamus saltuarius Gebler have different levels of attractiveness to semiochemicals. Although active use of chemical communication in both species is well known, there was no report on the differences in morphology and distribution of antennal sensilla between the two Monochamus species. The present study was carried out to explore the morphology, distribution, and ultrastructure of antennal sensilla of the two species using scanning and transmission electron microscopy. The overall shapes of the antennae were not different between M. alternatus and M. saltuarius. However, both M. alternatus and M. saltuarius exhibited sexual dimorphism overall. The antennae of each species were composed of the scape, pedicel, and nine flagellomeres, with four morphological types of sensilla: trichodea, basiconica, chaetica, and coeloconica. The four types occurred in varying numbers and distributions. The sensilla chaetica type was the most abundant in both species. Three types of sensilla (trichodea, basiconica, and chaetica) could be subdivided according to the two Monochamus species; sensilla trichodea could be divided into two subtypes, and sensilla basiconica and sensilla chaetica into three. All sensilla basiconica subtypes were multiporous, indicating that their primary function was olfactory. Sensilla trichodea subtype 2 was uniporous, indicating that the function of these sensilla might be gustatory. The morphological information obtained in our study provides a basis for future investigation of the sensory physiological function of each type of sensilla in the two species.     

Phylogenetic analysis of the genus Hexachlamys (Myrtaceae) based on plastid and nuclear DNA sequences and their taxonomic implications

Myrtaceae are one of the most species‐rich families of flowering plants in the Neotropics. They include several complex genera and species; Hexachlamys is one of the complex genera. It has not been recognized as a distinct genus and has been included in Eugenia, based on morphological grounds. Therefore, molecular systematic studies may be useful to understand and to help to solve these relationships. Here, we performed a molecular phylogenetic analysis using plastid and nuclear data in order to check the inclusion of Hexachlamys in Eugenia. Plastid (accD, rpoB, rpoC1, trnH‐psbA) and nuclear (ITS2) sequence data were analysed using Bayesian and maximum parsimony methods. The trees constructed using ITS2 and trnH‐psbA were the best able to resolve the relationships between species and genera, revealing the non‐monophyly of Hexachlamys. The molecular phylogenetic analyses were in agreement with previous morphological revisions that have included Hexachlamys in Eugenia. These results reinforce the importance of uniting knowledge and strategies to understand better issues of delimitation of genera and species in groups of plants with taxonomic problems. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 532–543.     

Ecologically relevant cryptic species in the highly polymorphic Amazonian butterfly Mechanitis mazaeus s.l. (Lepidoptera: Nymphalidae; Ithomiini)

The understanding of mimicry has relied on a strong biosystematic framework ever since early naturalists first recognized this textbook example of natural selection. We follow in this tradition, applying new biosystematics information to resolve problems in an especially difficult genus of tropical butterflies. Mechanitis species are important components of Neotropical mimetic communities. However, their colour pattern variability has presented challenges for systematists, and has made it difficult to study the very mimicry they so nicely illustrate. The South American Mechanitis mazaeus and relatives have remained particularly intractable. Recent systematists have recognized one highly polytypic species, whereas earlier work recognized the melanic Andean foothill races as a distinct species: Mechanitis messenoides. Recent molecular evidence suggests M. mazaeus and M. messenoides are genetically well differentiated, but evidence of morphological and ecological differences indicative of separate species was still lacking. Thus, it remains to be conclusively demonstrated whether this is an extreme case of a polymorphic mimetic species, or whether distinct co‐mimetic lineages are involved. Here we provide evidence that M. mazaeus and M. messenoides are ecologically distinct and identify consistent morphological differences in both adult and immature stages. These ecological and morphological differences are correlated with mitochondrial sequence data. In spite of some overlap in almost all traits, wing shape, adult colour pattern, and larval colour pattern differ between the two species, in addition to clutch size and larval host use in local sympatry. Although three well‐differentiated mitochondrial DNA (mtDNA) haplogroups were identified within these two species, one for M. mazaeus and two within M. messenoides, no morphological or ecological differences were found between two mtDNA haplogroups, both of which appear to belong to M. messenoides. We conclude that M. mazaeus and M. messenoides are distinct although highly polymorphic species, each with multiple sympatric co‐mimetic forms, and suggest that further work is needed to clarify the identity of other phenotypes and subspecies of Mechanitis. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 540–560.     

Effectiveness of mass trapping in the reduction of Monochamus galloprovincialis Olivier (Col.: Cerambycidae) populations

Monochamus galloprovincialis Olivier beetles vector the causal agent of pine wilt disease (PWD), nematode Bursaphelenchus xylophilus (Steiner and Bührer) Nickle, in Europe. Traps and attractants have been optimized for the capture of M. galloprovincialis, increasing the possibility of developing methods of lowering its population in PWD‐affected areas with the aim of either eradicating the disease or containing the spread of it. To evaluate the effectiveness of such mass‐trapping campaigns, two sets of experiments were carried out in 2010 and 2013. The release of 353 laboratory‐reared beetles in the experimental area of 2010 facilitated the evaluation of capture–mark–recapture (CMR) procedures in the calculation of population abundance estimates using the POPAN formulation of the Jolly–Seber model, a prerequisite for the assessment of mass trapping. Abundance estimates derived from best‐fitting parameters fell within one standard error of the real figures, proving the method appropriate. In 2013, four trap densities were tested in six 36 ha plots. To evaluate the removed proportions, the local beetle population was estimated in a contiguous 260 ha study area. A superpopulation of 21 319 individuals could be calculated from the CMR data, corresponding to a rough density of 82 individuals per hectare. Evaluated trapping densities removed 4.66%, 20.50%, 33.33% and 59.80% of M. galloprovincialis population at 0.02, 0.11, 0.25 and 0.44 traps/ha, respectively, thus the estimated 95% removal would occur at 0.82 traps/ha. These results suggest that substantial reduction of M. galloprovincialis abundances might be achieved via mass trapping and that this represents a very promising management method for the containment or eventual eradication of B. xylophilus at the areas affected by the PWD.     

Dispersal of Monochamus galloprovincialis (Col.: Cerambycidae) as recorded by mark–release–recapture using pheromone traps

The spread of the pine wood nematode (PWN), Bursaphelenchus xylophylus (Nematoda; Aphelenchoididae), the causal agent of the pine wilt disease, is greatly constrained to the dispersal of its vectors, long‐horned beetles of the Monochamus genus. Disease spread at global and regional scales has been mainly caused by human‐mediated transport, yet at a local scale, the short‐ and long‐distance dispersal behaviour of the beetles determine colonization dynamics. Three mark–release–recapture experiments using commercial traps and lures allowed the parameterization of the dispersal kernel under two landscape fragmentation scenarios for the only known European PWN vector, Monochamus galloprovincialis. The respective release of 171 and 353 laboratory‐reared beetles in continuous pine stands in 2009 and 2010 resulted in 36% and 28% recapture rates, yet, at a fragmented landscape in 2011, only 2% of the released 473 individuals could be recaptured. Recaptures occurred as soon as 7–14 days after their release, in agreement with the requirement of sexual maturation to respond to the pheromone–kairomone attractants. Data from the first two experiments were fitted to one mechanical and two empirical dispersal models, from which the distance dispersal kernels could be computed. Derived estimated radii enclosing 50% and 99% of dispersing M. galloprovincialis under continuous pine stands ranged between 250–532 m and 2344–3495 m depending on the replicate and choice of model. Forecasted recaptures in 2011 resulted in a moderate underestimation of long‐distance dispersal, probably influenced by the high degree of habitat fragmentation. In addition, trapping parameters such as the effective sampling area (0.57–0.76 ha) or the seasonal sampling range (426–645 m) could be derived. Observed results, derived dispersal kernels and trapping parameters provide valuable information for the integrated pest management of PWD. Furthermore, estimated dispersal distances indicate that ongoing clear‐cut measures for eradication in the European Union are likely ineffective in stopping the vectors dispersal.     

Geographically congruent large‐scale patterns of plastid haplotype variation in the European herbs Silene dioica and S. latifolia (Caryophyllaceae)

The closely related dioecious herbs Silene latifolia and Silene dioica are widespread and predominantly sympatric in Europe. The species are interfertile, but morphologically and ecologically distinct. A study of large‐scale patterns of plastid DNA (polymerase chain reaction–restriction fragment length polymorphism) haplotypes in a sample of 198 populations from most of the European ranges of both species revealed extensive interspecific haplotype sharing. Four of the 28 detected haplotypes were frequent (found in > 40 populations) and widespread. Three of these frequent haplotypes occurred in both species and the geographic distribution of each haplotype was broadly congruent in both species. Each of these three, shared and widespread haplotypes is likely to have colonized central and/or northern Europe after the last glaciation from one or more of refugial areas in southern Europe. Interspecific hybridization and plastid introgression within refugial regions and/or during the early stages of postglacial expansion is the most plausible explanation for the broadly similar distribution patterns of the shared, frequent chloroplast haplotypes in the two species. The fourth frequent, widespread haplotype was absent from S. latifolia and almost entirely restricted to Nordic S. dioica. It is most likely that this haplotype spread into the Nordic countries from a central or northern European source or from a refugial area in Russia. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 153–170.     

Physiological development and dispersal ability of newly emerged Monochamus galloprovincialis

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.     

ASYMMETRIC INTROGRESSION OF MITOCHONDRIAL DNA AMONG EUROPEAN POPULATIONS OF BLUE MUSSELS (MYTILUS SPP.)

Abstract.—Mytilus edulis and M. galloprovincialis are two blue mussel species that coexist in western Europe. Previously, we reported that M. galloprovincialis populations contain female and male haplotypes that are fixed in M. edulis populations as well as unique haplotypes. This study assesses whether paraphyly for these species is due to introgression or incomplete lineage extinction. The lineage extinction hypothesis predicts that the shared mtDNA haplotypes in M. galloprovincialis will be significantly diverged from those in M. edulis and form distinct sequence clades. In contrast, the introgression hypothesis proposes that M. edulis haplotypes have only recently been introduced into M. galloprovincialis through hybridization with relatively little divergence accumulating between the shared RFLP haplotypes. We examined 80 mtl6S gene sequences for both the maternal and paternal mtDNA lineages from mussels sampled from various European populations and found strong support for the introgression hypothesis. In addition, we found that M. edulis mtDNA haplotypes appear to be introgressing into mussel populations in the Baltic Sea, which have predominantly M. trossulus nuclear genotypes, indicating that introgressive hybridization is prevalent among European mussel populations.     

A new cytochrome b phylogroup of the common vole (Microtus arvalis) endemic to the Balkans and its implications for the evolutionary history of the species

The phylogeographic architecture of the common vole, Microtus arvalis, has been well‐studied using mitochondrial DNA and used to test hypotheses relating to glacial refugia. The distribution of the five described cytochrome b (cyt b) lineages in Europe west of Russia has been interpreted as a consequence of postglacial expansion from both southern and central European refugia. A recently proposed competing model suggests that the ‘cradle’ of the M. arvalis lineages is in western central Europe from where they dispersed in different directions after the Last Glacial Maximum. In the present study, we report a new cyt b lineage of the common vole from the Balkans that is not closely related to any other lineage and whose presence might help resolve these issues of glacial refugia. The Balkan phylogroup occurs along the southern distributional border of M. arvalis in central and eastern Bosnia and Herzegovina, Montenegro, and eastern Serbia. Further north and west in Slovenia, Bosnia and Herzegovina, and Serbia, common voles belong to the previously‐described Eastern lineage, whereas both lineages are sympatric in one site in Bosnia and Herzegovina. The Balkan phylogroup most reasonably occupied a glacial refugium already known for various Balkan endemic species, in contrast to the recently proposed model. South‐east Europe is an absolutely crucial area for understanding the postglacial colonization history of small mammals in Europe and the present study adds to the very few previous detailed phylogeographic studies of this region. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 788–796.     

Hidden diversity in bent‐winged bats (Chiroptera: Miniopteridae) of the Western Palaearctic and adjacent regions: implications for taxonomy

The taxonomic status of bent‐winged bats (Miniopterus) in the Western Palaearctic and adjacent regions is unclear, particularly in some areas of the eastern Mediterranean, Middle East and Arabia. To address this, we analysed an extensive collection of museum materials from all principal parts of this distribution range, i.e. North Africa, Europe and southwest Asia, using morphological (skull) and genetic approaches (mitochondrial DNA). Linear and geometric morphometric analysis of cranial and dental characteristics, together with molecular phylogeny, suggested that Miniopterus populations comprise four separate species: (1) M. schreibersii sensu strictissimo (s.str.) – occurring in Europe, coastal Anatolia, Levant, Cyprus, western Transcaucasia, and North Africa; (2) M. pallidus – occurring in inland Anatolia, Jordan, eastern Transcaucasia, Turkmenistan, Iran and southern Afghanistan (Kandahar); (3) a Miniopterus sp. – recorded from Nangarhar province in eastern Afghanistan, which we tentatively assign to M. cf. fuliginosus; and (4) a Miniopterus sp. with Afro‐tropic affinities confirmed from south‐western Arabia and Ethiopia, which we tentatively name M. cf. arenarius. The latter two species are well differentiated by skull morphology, while M. pallidus possesses very similar skull morphology to M. schreibersii. The results also suggest the existence of a possible new taxon (subspecies) within M. schreibersii s.str. inhabiting the Atlas Mountains of Morocco. © 2012 The Linnean Society of London