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BACKGROUND Methyl bromide is an ozone depleting substance and is still being used for quarantine treatment of wood products and logs. Ethanedinitrile (C2 N2 ) is a new potential alternative fumigant and has been investigated as a timber fumigant because it has shown better penetration through timber and responds fast to insects and nematodes. This article reports on laboratory and commercial-scale trials with C2 N2 for important wood destroying pests namely Tomicus piniperda (Pine bark beetle) adults, Hyphantria cunea (Fall webworm) lavae, Reticulitermes speratus (Japanese Termite) adults and Cryphalus fulvus (Scolytidae) (Yellow minute bark beetle) which naturally infests pine logs. RESULTS Tomicus pi:niperda adults were more tolerance than H. cunea lavae and R. speratus adults with lethal concentration × time affecting 99% mortality (LCt99 ) values of 27.84, 7.49 and 3.30 g h m-3 , respectively. Ethanedinitrile shows exceptionally high toxicity to adult R. speratus which was almost 26 times more toxic than methyl bromide. The complete control of larvae and adults stages of C. fulvus was achieved at concentration × time (Ct) products from 89.6 g h m-3 in a 6-8 L fumigation chamber. Temperature-depending trials on C. fulvus were conducted with C2 N2 doses of 30 at 21 ± 6 and 40 g m-3 at 9 ± 3 and 2 ± 2 °C for 24 h. The Ct products of 182.2, 227.8 and 268.6 g h m-3 were obtained and C. fulvus was completely controlled at all tested temperatures. CONCLUSION Ethanedinitrile could offer quarantine treatment for wood products and logs for the control of wood destroying insect pests and termites.

The present study was conducted in the suburban forest “Seich Sou”, which is located at the north-east of Thessaloniki city (north Greece). “Seich Sou” is one of the most significant suburban forests of North Greece. However, many disastrous events have taken place in the suburban forest during the last 25 years, caused by either human interference or other biotic/abiotic factors, such as insect outbreaks. In the present study, erosion measurements and field data were collected using a combination of silt fences (USLE plots) and depositions retained behind the constructed check-dams, aiming to monitor the impact of the significant biotic and abiotic disturbances (forest fires, insect outbreaks, logging) in Seich Sou forest. Specifically, the aim of this study is to present a cost-effective and time saving methodology towards the achievement of accurate and reliable soil erosion measurements and field data acquisition. Additionally, the installation details, data recording and collection, field work, supplementary materials and the advantages of silt fences and check-dams are presented in detail, as well as the limitations of the methods and the difficulties during the installation, maintenance and data collection period. The proposed methodology could be effectively applied in many environments and in the context of varied purposes, to quantify the erosion and runoff processes with high accuracy, as well as to increase the accuracy of soil erosion modeling performance, through implementation of calibration and/or validation processes, which is a major issue for the scientific community.

Introduction Production of resin in damaged roots is a significant characteristic of the trees damaged by root rot caused by Heterobasidion annosum (Fr.) Bref. and is one of the symptoms of the disease. Resin production is caused by changes in a tree metabolism and its considerable losses in moisture, which also leads to changes in the composition of monoterpenes in essential oils of the resin. Bark beetles may identify the composition of these essential oils by smell, indicating weakened trees and an opportunity to attack them. Thus, in the stand with trees damaged by root rot, bark beetles like Tomicus piniperda L. and T. minor Hart. may attack only trees in the active part of the root rot foci. A rapid spread of the Ips acuminatus bark beetle may be brought about by changes in the composition of essential oils in pine stands as a result of a change in the water regime of trees due to recent climatic fluctuations. The aim of the research was to detect changes in the essential oils of pine trees with varying damage degrees in their root systems in the root rot foci. Materials and Methods Samples of resin were taken from the 4th-grade pine trees growing in Kharkiv Region, damaged by root rot in varying proportions (1–10%, 11–20%, 21–30%, and 31–40%). To determine the damage extent, we excavated the trees’ root systems and measured them. Essential oils were extracted from the resin by steam distillation. The composition of turpentine oils was analyzed by separating them on a LHM-8M gas-liquid chromatograph. We identified monoterpenes by the sequence and time with which the components were coming out of the column. The proportion of the components in essential oils was determined by their peaks part in the total area of the chromatogram. Results and Discussion Trees with the initial stage of the root damage (1–10%) mainly bordered to site with healthy trees. The trees with the root damage of 11–30% grew on the edge of the gap within the disease foci. The most damaged trees (31–40%) were mainly located in the open space of the gap. The results of the study showed that the content of α-pinene and camphene reduces under the influence of the disease. The trees with the root damage of 11–30%, growing on the edge of the gap, have the least of these components compared to healthy trees. However, the trees with the root damage of 31–40% growing in the open space of the gap have a higher level of monoterpenes compared to that in less damaged trees. We also noted that the content of β-pinene is 1.8–2 times higher in affected trees compared to healthy ones. The content of ∆3-carene in the trees with the root damage of 1–10% or 40% respectively, was 17% and 23% lower compared to healthy trees. It was, on the contrary, 15–16% higher in the trees with 11–30-percent damage, growing in the active part of the root rot focus, compared to healthy trees. The correlation analysis indicated a strong negative relationship between the content of α-pinene and ∆3-carene, namely r0.05 = -0.747. The monoterpenes α-pinene, β-pinene, and ∆3-carene predominate in resin essential oils. Proportions of other monoterpenes, such as camphene, limonene, dipentene, and ŋ-cymene are negligible. As a bark beetle attacks trees in the active part of the root rot focus (damage degree 11–30%), both a 70-percent decrease of α-pinene in the essential oils content and a 15-percent increase of ∆3-carene (compared to healthy trees) may serve as a signal and indicate the tree’s weakening, as well as point at the possibility for the tree to be attacked. Conclusions The dynamics of the monoterpenes content in essential oils of resin in trees damaged by root rot (Heterobasidion annosum (Fr.) Bref.), with the progress of the disease depends on both the root damage extent and the position of the tree relative to the active part of the dieback focus. The β-pinene content is significantly higher in the affected trees and scarcely depends on the progress of the disease. The content of α-pinene and camphene decreases under the influence of the disease. Their lowest content, as compared with healthy trees, was noted in the trees at the edge of the root rot focus whose roots damage extent was 11–30%. The content of ∆3-carene in these trees was 15–16% higher. A strong negative relationship was found between the content of a-pinene and ∆3-carene. We came to the conclusion that as bark beetles inhabit the trees growing in the active part of the root rot foci (root damage 11–30%) a 70-percent decrease of a-pinene in the content and a 15-percent increase of ∆3-carene (compared with that in healthy trees), may serve as a signal and indicate the possibility for the tree to be attacked. 2 Figs., 2 Tables, 14 Refs.

The health condition of Scots pine (Pinus sylvestris L.) forests in Zhytomyr region has deteriorated sharply since the 2009 drought. This phenomenon was initially explained by the negative impact of climatic factors. However, the important role of bark beetles (Coleoptera: Curculionidae: Scolytinae) has been proved, particularly Tomicus piniperda (Linnaeus, 1758), T. minor (Hartig, 1834), Ips acuminatus (Gyllenhal, 1827) and I. sexdentatus (Boerner, 1767). Bark beetles are recognized to be a direct cause of tree mortality after their weakening by any cause. Therefore, it is hypothesized that after the drought of 2009, two outbreaks of different groups of bark beetles occurred. To confirm this hypothesis, we analyzed the dynamics of population indices of the most common species during their mass propagation in the forests of Zhytomyr region for the period of 2013-2019. The analysis of prevalence, parent and progeny population density, and propagation energy of bark beetles obtained on 550 sample points from 61 model trees was carried out. The prevalence was evaluated as the proportion of trees with the signs of bark beetle colonization. Parent population was evaluated by a number of bark beetles' nuptial champers (families) plus a number of mother galleries per 1 sq. dm. Progeny population was evaluated by exit holes number per 1 sq. dm. The energy of propagation was evaluated as the ratio of population density of progeny and parents. It is found out that in the bark beetle complex in the foci of drying out until 2014, T. piniperda and T. minor dominated, and since 2015, I. acuminatus and I. sexdentatus dominated, which have several generations per year. It was shown that the main trends in the development of the bark beetle complex in pine stands of Zhytomyr region during the years of research were determined by the dynamics of the populations of I. acuminatus (the dominant species). The values of all population indices show the increase of intraspecific competition in I. acuminatus population since 2016, and interspecific competition in 2018-2019. Competition and the accumulation of entomophages in the foci of drying out are expected to bring to the collapse of the bark beetles' outbreak.

Tomicus piniperda (Coleptera, Curculionidae) is a native insect in Europe and now potential enabler of the invasive fungal pathogen of pines, Fusarium circinatum. The co-occurence of T. piniperda and F. circunatum could increase disease incidence via (1) insect wounding when they bore galleries into shoots of healthy trees, and (2) by acting as vectors that introduce fungal propagules directly. The extent of damage by F. circinatum is likely to be influenced by tree defenses, which can depend upon pine species, environmental conditions, and responses to other biotic and abiotic challenges. Indirect interactions among plant enemies can arise when the attack by one enemy alters the shared host plant in a way that affects a second enemy. We tested for indirect interactions between T. piniperda and F. circinatum mediated by plant defenses. Our study employed 100 potted, identically treated, seedlings of Pinus pinaster and P. radiata. Plants were randomly allocated to one of five different treatments: inoculation with T. piniperda alone, inoculation with F. circinatum alone, inoculation with T. piniperda and F. circinatum together, a mock treatment with sterilized water, and true controls. We assessed plant mortality, and measured plant height and diameter, crown size, resin flow after T. piniperda attack, the size of lesions from fungal infection, and phloem chemistry (terpenes and nitrogen). There were conspicuous differences between pine species in their defensive responses to inoculations: P. pinaster showed increases in numerous terpenes following attack by T. piniperda but was unresponsive to F. circinatum, while P. radiata increased terpene concentrations with exposure to either F. circinatum or T. piniperda. In P. radiata, fungal growth within the plant (as reflected by lesion size) was reduced by coincident insect attack. This suggests that plant defensive responses against the insect also functioned as deterrents to a fungal enemy. Thus the combination of T. piniperda and F. circinatum should not be as dangerous to pine stands as if the insect disabled defences against the fungus. Nonetheless, the insect can only increase fungal introductions by increasing wounds and moving propagules. There is a need for field studies of damage from F. circinatum in different pine species with low vs. high abundance of T. piniperda. Better understanding of pine defenses against F. circinatum, and genetic variation in defense responses, would contribute to the development of safe, effective, and sustainable tactics for managing damage from F. circinatum to pine forests in Spain and elsewhere.

Our study was conducted in the suburban forest of Thessaloniki (Seich Sou), which constitutes one of the most significant suburban forests of Greece and is located northeast of Thessaloniki. In 1997, more than the half of the forest area was destroyed by a wildfire, while recently (May 2019), a significant insect outbreak by the bark beetle Tomicus piniperda was detected. The insect action still goes on, while the infestation has destroyed so far more than 300 ha of forest area. Extensive selective logging and removal of infected trees from the forest were carried out in order to mitigate and restrict the outbreak spread. In the current study, silt-fenced erosion plots were installed on representative locations of disturbed (by fire and insect action) and undisturbed areas, in order to quantify the effect of the above-mentioned forest disturbances on soil erosion and correlate the height and intensity of precipitation with the soil erosion rate. The results show that there was no statistically significant increase in soil erosion in the areas of insect outbreak compared with the control plots. However, there was a statistically significant increase in soil erosion in areas where logging works had been applied as an infestation preventive measure. In addition, the study revealed that 25 years after the forest fire, the erosion rate is still at higher level compared with the undisturbed forest areas. This study could be considered as one of the first attempts to evaluate the impact of an insect outbreak infestation on soil erosion, while there is also a great lack of information concerning the assessment of long-term post-fire effects on the soil erosion of a forest ecosystem.

Tomicus piniperda (Linnaeus, 1758) Records. DON, LUG [Nikulina et al., 2015: 25]., Published as part of Arzanov, Yu. G., Martynov, V. V. & Nikulina, T. V., 2021, A contribution to the fauna of weevil beetles (Coleoptera: Curculionoidea) of the Central Donbass, pp. 5-44 in Caucasian Entomological Bulletin 17 (1) on page 42, DOI: 10.23885/181433262021171-544, http://zenodo.org/record/8145644, {"references":["Nikulina T., Mandelshtam M., Petrov A., Nazarenko V., Yunakov N. 2015. A survey of the weevils of Ukraine. Bark and ambrosia beetles (Coleoptera: Curculionidae: Platypodinae and Scolytinae). Zootaxa. 3912 (1): 1 - 61. DOI: 10.11646 / zootaxa. 3912.1.1"]}

The pine shoot beetle, Tomicus piniperda (L.), is considered one of the most destructive pests of Scots pine, Pinus sylvestris (L.), in Europe. At high population densities, its feeding in the shoots of living pine trees may lead to substantial shoot and subsequent growth losses. After a storm-felling in southern Sweden in January 2005, there were high amounts of breeding material and a subsequent risk for bark beetle outbreaks. To study the beetle's reproductive success, population levels and risks for growth losses, we analysed bark samples of colonized trees, and counted fallen pine shoots. During the first season after the storm-felling, the pine shoot beetle population level was low. However, due to high reproductive success beetle numbers markedly increased in the second season, and there were high rates of successful colonization of available host material in following years. Shoot damage levels concomitantly rose in 2005-2006, then declined in 2007 and 2008. However, the accumulated shoot losses do not indicate any subsequent growth losses, as the recorded shoot damage levels were below those earlier seen in connection with growth reductions in damaged pine stands.

Background and purpose The pine shoot beetles Tomicus piniperda and Tomicus minor are secondary tree pests attacking weakened Pinus sylvestris and Pinus nigra. Outbreaks occasionally occur, causing considerable economic damage. The microsporidian pathogen Canningia tomici infects T. piniperda as its principal host. Bioassays were used to study the infectivity of C. tomici to both beetle species, as well as vertical transmission, and effects on survival and fecundity. Materials and methods Field collected beetles from several locations in Austria (Lower Austria, Burgenland and Styria), Finland (Hyytiälä), Poland (Sękocin), the Czech Republic (Stará Boleslav), and Croatia (Korenica) (3410 T. piniperda, 413 T. minor) were dissected and evaluated for the presence of C. tomici. Uninfected beetles for infection experiments were only collected from the Austrian sites.Canningia tomici spores were extracted from the infected organs of T. piniperda by dissection and host tissue grinding. The number of spores suspended in water was counted in a hemocytometer. Infection experiments began with T. piniperda and T. minor as soon as parental beetles were available in the field in spring, or filial beetles were emerging from infested log sections in the laboratory. To test the effect of maturation feeding on infection success, filial beetles of both species were either inoculated immediately after emergence from a log section, or were allowed to feed on P. sylvestris twigs for several days first. Filial beetles were kept in Petri dishes containing P. sylvestris twigs at 8°C and long-day conditions (16L:8D) during the maturation feeding period. Afterwards, they were removed from the twigs, starved for 24 hours, and then inoculated with a 1-µl spore suspension or water. All beetles checked daily until death, dissected and inspected for the presence of C. tomici spores. All data were analyzed with the software program. Frequency data sets were compared using Chi-square analysis. Multiple comparisons were controlled for Type I errors using the Bonferroni method. The datasets of multiple dependent scale variables were analysed using the LM multivariate procedure, testing the effects of the following factors: year, temperature, inoculation, successful infection, maturation feeding, and sexResultsThe overall prevalence of C. tomici in T. piniperda was 1.9%, with significantly more female T. piniperda infected. No infections were observed in T. minor. After feeding spore suspensions to parental and filial T. piniperda and T. minor, between 0% and 67% of the beetles were successfully infected, regardless of the incubation temperature or the beetles’ sex. The beetles’ survival time was significantly influenced by the incubation temperature and the successful infection; in filial beetles the maturation feeding period was also an important factor. A lower incubation temperature and a successful infection caused both species and generations to survive longer.Conclusion We conclude that when C. tomici infects the reproductive organs of its hosts, this extends the host's lifespan, leading to better reproduction, transmission, and survival of the pathogen in host populations. This is also reflected by higher infection rates of T. piniperda in Finland and Poland, as compared to Austria.

The contribution of non-lethal pathogenic attacks to tree death is still unclear. Manion’s theory of the spiral of decline predicts that tree decline and death occurs because of a sequence of predisposing, inciting and contributing events. To understand whether pathogens can act as predisposing or inciting factors, we tested whether a sequence of non-lethal pathogen attacks causing crown defoliation could lead to a chronic decline in tree health and predispose trees to die. Scots pine (Pinus sylvestris) trees predisposed or escaping (non-predisposed) a first outbreak by the pathogen Gremmeniella abietina (predisposing event) were compared in terms of survival and susceptibility to secondary pests (contributing event) after a second G. abietina outbreak (inciting event). Four years after the inciting event, mortality among predisposed trees was up to five times higher than among trees escaping the first epidemic. Predisposed trees were twice as susceptible to secondary attacks by the common pine shoot beetle (Tomicus piniperda). Ten years after the inciting event, severely predisposed trees had not been able to restore their crowns and still showed stagnated growth. This study showed that pathogen-induced defoliation can act as predisposing and inciting factors for tree death, reducing the capacity of trees to survive short- or long-term stressing events, such as bark beetle attacks. We also showed that tree decline can result from a combination of predisposing and inciting events caused by pathogens.

Many insect species are able to cause important damage in agriculture, forestry and human health due to their ability to feed on plants and animals tissues or transmit fungi and other diseases. Entomologists have long recognised that periods of atypical weather conditions, such as drought, excessive precipitation or unusually hot or cold weather, have great impact on insect development. Understanding the effects of climate on ecological processes has become increasingly important in entomological research as a result of global warming, which appears to be affecting their geographic ranges and population dynamics. In Mediterranean ecosystems, pine shoot beetle, Tomicus destruens Woll, and pine processionary moth, Thaumetopoa pityocampa (Denis & Schiff), are examples of species that origin problems to man. Tomicus destruens is a phytophagus insect responsible for several damages on maritime pine (Pinus pinaster Aiton) stands during its feeding on needles and its capacity to inoculate fungi and other decaying biotic agents. Thaumetopoea pityocampa is also responsible for damages in P. pinaster stands and can provoke strong allergic reactions due the presence of urticains hairs. Both species have a physiological response to the temperature variation, which is observed in the life cycle duration and in the mortality rate. The present study aims to highlight the effect of global change/global warming in the bioecology of those Mediterranean species and their implication in forest productivity and human health.

Bark beetles infest several pine tree species, often creating major economic losses. Biotic interactions between Scolytinae populations inhabiting Pinus sylvestris were analyzed using a new sampling method involving a two dimensional division of tree space resources into units and sections. The goal was to evaluate the effects of the type of available reproduction material on insect infestation. The P. sylvestris stands in this study included an analysis of bark beetles colonizing dead trees and uninfested living trees (trap trees). Analyzed trees were harvested and their stems divided into ten equal units; each unit was halved into two sections (half of the stem circumference). The colonization of dead trees by insects was evaluated immediately after cutting for infested trees and 2 months after cutting for trap trees. The type of breeding material significantly affected the species composition of bark beetles infesting P. sylvestris. The dead trees were colonized mostly by Trypodendron lineatum and Tomicus minor, and to a lesser extent by Tomicus piniperda, which dominated in trap trees. Tomicus piniperda and T. lineatum preferred thicker stems; however, T. minor, Hylurgops palliatus and Pityogenes bidentatus preferred thinner ones. The application of the new sampling method helped to increase the accuracy of niche segregation among insect species. The results of niche segregation indicate bark beetles exhibited spatial specialization in the use of resources, mainly related to the moisture content of breeding material and the availability of food resources which is the main factor determining the coexistence of bark beetles in the same environment.

The pine shoot beetle, Tomicus piniperda, is a secondary colonizer of pines and other conifers. Although it is necessary to understand interactions of this insect with other organisms, few studies have focused on its fungal associates. This study focused on the effect of geographical distance on the occurrence of fungi carried by the beetle. Adult beetles were collected from Scots pine (Pinus sylvestris) in North (Rovaniemi) and South (Hyytiala) Finland. The mycota was isolated and identified using a combination of morphological and molecular data. The results revealed a great diversity of fungal taxa isolated from T. piniperda, with a total of 3073 isolates representing 20 taxonomic units. The most frequently isolated fungi in the bark beetles from North Finland were Beauveria bassiana, Kuraishia sp., whereas Penicillium velutinum was mostly observed in the insects from South Finland. Ophiostoma canum and Ophiostoma minus were also isolated from the beetles from both North and South Finland. The number o...

Producción Científica, Bark beetles (Coleoptera, Scolytinae) carry a diverse filamentous fungal community sometimes acting as vectors or carriers of phytopathogens. In this study, mycobiota carried by two Tomicus species (Tomicus piniperda and Tomicus destruens) were investigated through (i) morphological and molecular identification of taxa; (ii) taxonomic richness, diversity, evenness, dominance and phoresy indices; (iii) ecological network analysis and (iv) statistical co-occurrence analysis. The studied mycobiota were formed by eleven taxa and showed a moderate fungal diversity with low evenness. The fungus Sydowia polyspora was significantly abundant and dominated the community. All the fungal taxa were randomly associated. Both insect species (T. piniperda and T. destruens) were collected from plantations of Pinus radiata infected by Fusarium circinatum. The ecological factors that could drive community ecology and phoretic links between fungi and bark beetles are discussed., Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-69370-R), Ministerio de Economía, Industria y Competitividad (project AGL2012-39912), Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (grant ORDEN EDU/1083/2013)

In a single stand, the colonization of 128 girdled Scots pine trees (Pinus sylvestris L.) by bark- and wood-boring beetles was examined during two vegetation periods after treatment. The trees were girdled on four different dates in April, July, October and January. The time elapsed from girdling to the first attack of bark- and wood-boring beetles was 1–19 months (mean = 10.7) and differed significantly among trees girdled on different dates. The part of the tree and the date and wave (rank) of colonization were the most significant factors that explained a considerable portion of the variability in the occurrence of bark- and wood-boring beetles. The species composition changed dramatically from the tree base to its top and branches. The colonization of trees was initiated most frequently in the upper thin-barked part of the trunk and in thick branches. In total, 32 species of bark- and wood-boring beetles colonized the studied trees. Particular species were significantly associated with certain periods of tree dieback and colonization (colonization waves). Phaenops cyanea (F.) and Pissodes piniphilus (Hbst.) were by far the most aggressive first-colonizing species. Pityogenes chalcographus (L.), Ips acuminatus (Gyll.) and Tomicus minor (Htg.) were shown to be moderate-aggressive species, followed by Tomicus piniperda (L.), Monochamus galloprovincialis (Germ.) and Pissodes pini (L.). The remaining species were designated as not harmful and saprophagous.

The presence and diversity of beetle pathogens associated with different tree species in Bulgaria was investigated. In total, 818 specimens belonging to 22 beetle species were examined. Pathogens occurred in 9 host species. The infections were found in the gut (virus, nematodes, protozoans, microsporidia) and haemolymph (nematodes) of the infected insects. The following pathogen species: ItEPV, Beauveria bassiana, B. brongniartii, Isaria farinosa, Gregarina typographi, Gregarina spp., Chytridiopsis typographi, Chytridiopsis sp., and nematodes were revealed. Insects with mycoses were mummified and filled up with fungal structures, formed pseudosclerotium. Most pathogens were established in bark beetles (Scolytinae). For the first time, the fungus B. bassiana was reported in Tomicus piniperda, Orthotomicus longicollis, O. erosus, X. spinole, Taphrorychus villifrons and Phylobius sp. in Bulgaria. We also present the first records of gregarines in O. longicollis, Acanthocinus aedilis, Rhagium inquisitor, Pyrochroa coccinea, and of the microsporidium Chytridiopsis sp. in O. longicollis.

Department of Education, Universities and Research of the Basque Country Department of Agriculture and Fisheries of the Basque Country

We studied the infestation rate of Scots pine Pinus sylvestris by xylophagous insects in relation to distance from forest lakes in eastern Latvia, northern Europe. In summers of 2008 and 2009, we felled 72 pines of approximately 65 years age. Sections of the logs were incubated in insect emergence traps. The trees located near lakes were significantly less infested by xylophagous insects than those sampled at greater distances from the lakes. We also tested the ability of Tomicus piniperda , the most abundant species of xylophagous insects in our samples, to resist the entomopathogenic fungus Beauveria bassiana . The results show that beetles captured near lakes were more susceptible to the fungal infection than individuals sampled away from forest lakes, indicating that the beetles far from lakes afforded to invest more in immunity during the larval phase. During the warmest days in summer the mean maximum ambient temperature was 2.32 °C lower near lakes than away from lakes. Since increased temperatures not only trigger drought stress, but may potentially also cause temperature-sensitive mortality of conifers, a warmer microclimate may lower resistance of pine trees to attacks of xylophagous beetles. In weakened trees, insects can invade more easily resulting in increased investment in immunity in bark- and wood-boring insects. This is the first demonstration of drought-induced positive feedback in xylophagous insects infesting Scots pine. Since bark beetles are common pests of conifers, our results may be important in forest pest management.

In the year 2000, large areas of forest in Sweden, mainly 30–50 year old Pinus sylvestris (L.) stands, were attacked by the fungus Gremmeniella abietina (Lagerb.) Morelet. The aims of this study were to investigate: (i) the relationship between G. abietina-induced tree crown transparency (CT) and P. sylvestris (L.) tree mortality; (ii) the influence of CT levels on stem growth; (iii) the recovery of the crown; and (iv) the association of CT and colonization by Tomicus piniperda (L.). Thirty-five permanent sample plots were established in five P. sylvestris stands (38–46 years old), infested by G. abietina, and 23 plots in four reference stands, not obviously infested. During the 5 years following the attack, the total mortality amounted to 454 trees ha−1 and 7.8 m2 ha−1, on average, in the five infested stands, corresponding to 42% of the trees and 34% of the basal area at the time of the attack. Most of the mortality occurred within 2 years of the attack. The mortality of individual trees (2002–2005) was found to be related to the crown transparency (CT), the position of needle loss within the crown and the tree diameter at breast height. Based on our modeling, the probability of mortality was substantially increased if the initial CT-value was higher than 85%. Growth reductions were detected for individual trees with an initial CT of >c. 40%. In contrast, trees with a low initial CT ( The trees in the infested stands that were still alive in spring 2005 had started to recover in terms of CT. Breeding of T. piniperda on the P. sylvestris (L.) stems occurred almost exclusively on stems with a CT > 90%. The data from this study suggest that when a P. sylvestris (L.) stand has been attacked by G. abietina, trees with a CT above 80% should be felled; the remaining trees will have a high probability of survival and resistance to successful breeding by the T. piniperda.

Sirex noctilio is a woodwasp native to Eurasia and Northern Africa and has recently been found infesting pines in eastern North America. Its pest status in this new range is not yet known, although it is an important pest in other areas where it has been introduced. Pinus spp. in North America are hosts to several native and alien species of subcortical insects. Interactions between the woodwasp and these species may influence its distribution or the characteristics of its life history, thus affecting its population dynamics over time. 2 Sixty S. noctilio-infested Pinus spp. were felled in Ontario, Canada, and all phloem- feeding and woodboring insects were collected and identified from each 1-m section of the tree. 3 Sirex noctilio was in a tree alone 10% of the time but commonly shared the tree with subcortical beetles, such as Tomicus piniperda, Pissodes nemorensis, Ips grandicollis, Gnathotrichus materiarius and Monochamus carolinensis .T he woodwasp was distributed throughout the tree stem and this distribution overlapped with that of the beetles. 4 Fewer but larger S. noctilio males emerged from trees with beetles compared with those without, although there was no statistical difference in females. 5 These findings suggest that co-habiting beetles could negatively affect S. noctilio population dynamics over time. The potential mechanisms for this interaction are discussed.

Prothallonema tomici n. sp. (Tylenchida: Sphaerulariidae) is described as a parasite of the bark beetle Tomicus piniperda (Linnaeus) (Coleoptera: Curculionidae: Scolytidae). The new species is characterised by the relatively short body (0.3-0.5 mm) and short prolapsed uterus ((0.16-0.44) × (0.065-0.15) mm), relatively anterior position of the vulva (83.8-85.5%), stylet with fine asymmetrical basal knobs, hemizonid and hemizonion, four incisures, subterminal phasmids and tail terminus always curved dorsad. The entomoparasitic and mycetophagous generation were observed in the body cavity of T. piniperda. Comparing the two generations of J4 showed that the mycetophagous generation had a longer and more robust body, shorter pharynx and tail, longer reproductive system and vulva located further posteriorly. It can be concluded that, in the haemocoel, the entomoparasitic generation can develop through all stages whilst the mycetophagous generation develops to the J4 and then dies.

In 1982–1984 window-traps baited with logs of Pinus sylvestris captured many more specimens of Tomicus piniperda and T. minor than did traps baited with logs of P. contorta or Picea abies, whereas unbaited control traps caught no beetles. Thus, primary attraction was important in guiding these beetles to the host material. In the laboratory, both beetle species oviposited and produced progeny in logs of P. sylvestris and P. contorta. The performance of T. minor was, however, poor in both hosts. For T. piniperda, fewer eggs were laid in P. contorta than in P. sylvestris and the emergence occurred slightly earlier in the latter than in the former species. The attack density, brood production and adult weight was similar in both hosts. Successful shoot-feeding of both beetle species was observed on both hosts when beetles were enclosed in cages on mid-crown branches of living trees. Thus, both T. piniperda and T. minor could survive entirely on lodgepole pine. However, there is no reason to assume more severe attacks of the pine shoot beetles on lodgepole pine than on Scots pine. Zusammenfassung Pinus contorta als potentieller Wirt fur Tomicus piniperda (L.) und T. minor (Hart.) (Col., Scolytidae) in Schweden Mit Hilfe von Fensterfallen, unter denen sich Pinus sylvestris-Stammstucke zur Anlockung befanden, wurden 1982 bis 1984 weit mehr Individuen der beiden Waldgartner gefangen als uber P. contorta oder Picea abies-Stammstucken, wahrend Fallen ohne Kombination mit Lockholz ohne Kafer blieben. Somit war die Primaranlockung zur Hinfuhrung dieser Borkenkafer zum Brutmaterial entscheidend wichtig. Im Labor brachten beide Waldgartner in Stammstucken von P. sylvestris und P. contorta Nachkommen hervor; doch war in beiden Wirtsholzern die Nach-kommenzahl von T. minor gering. T. piniperda legte in P. contorta weniger Eier als in P. sylvestris, und das Schlupfen erfolgte etwas spater als dort. Die Befallsdichte, Brutproduktion und das Adultengewicht waren in beiden Wirtsbaumen ahnlich. Erfolgreicher Triebfras beider Kaferarten wurde in beiden Wirten beobachtet, als sie in den Kronen lebender Baume an Zweigen eingekafigt wurden. Somit konnen die beiden Waldgartner an P. contorta uberleben. Jedoch besteht kein Grund anzunehmen, das der Befall von P. contorta schwerer ware als von P. sylvestris.

Development of Tomicus piniperda was studied in the field on the arctic circle and at constant temperatures in the laboratory. A T. piniperda population living in pulpwood stacks was sampled successively throughout three summers and a total of 541 sample bolts was dissected. Temperatures were measured by a datalogger at hourly intervals. A hierarchial data base was built of the material and development curves for each stage were constructed. Differences in development were very large between the years and stack layers. The onset of winter interrupted development prematurely in two of the three years. A non-linear model of development was fitted to the laboratory material. The components of variation in emergence times of bark beetles were identified as being sequential attack, sequential oviposition, and randomly varying developmental rates. The distribution of emergence was modeled, and it was compared to the field data. According to the model, development seemed to take longer in the field. That was suggested result from a bias at the cold end of the model, sequential attack, and differences in mortality rates. Using empirical logistic models of emergence on degree-days and climatological data, emergence was projected over maps. Zusammenfassung Die Rolle der Temperatur in der Populationsdynamik von Tomicus piniperda (L.) (Col., Scolytidae) unter nordlichen Verhaltnissen Es wurde die Entwicklung des grosen Waldgartners im Freiland innerhalb des arktischen Polarkreises sowie im Labor bei konstanten Temperaturen untersucht. Proben einer T. piniperda-Population wurden aus gelagertem Holz drei Sommer lang entnommen, wobei 541 Stammstucke ausgewertet wurden. Auf dem gewonnenen Material wurde eine hierarchische Datenbasis errichtet und auf ihr Entwicklungskurven fur jedes Stadium konstruiert. Zwischen den Jahren und Holzlagerstellen ergaben sich starke Unterschiede. Der Winter unterbrach in zwei von drei Jahren die Entwicklung vorzeitig. Es wurde ein nicht-lineares Entwicklungsmodell anhand des Labormaterials konstruiert. Die Ursachen der Variation der Kaferschlupfzeit wurden auf die zeitlichen Unterschiede des Befalls, der Eiablage und auf die zufallig variierenden Entwicklungsraten zuruckgefuhrt. Die Phanologie des Schlupfvorganges wurde modellhaft konstruiert und mit den Freilanddaten verglichen. Entsprechend diesem Modell dauerte die Entwicklung im Freiland langer. Dies wurde zuruckgefuhrt auf eine zu starke Betonung der niedrigen Temperaturen im Modell, auf zeitliche Befallsunterschiede sowie auf Unterschiede in den Mortalitatsraten. Unter Verwendung des empirisch auf Tagesgrade und klimatische Daten aufgebauten Modells wurden die Linien gleicher Schlupfzeit in Finnland auf Landkarten ubertragen.

Changes in structure or community composition within forest ecosystems and their patterns in time and space affect insect populations. Silvicultural measures may cause temporary disturbances or have long-term influences on the ecosystems. They may determine insect distribution and general levels of abundance or they may change the manner in which populations fluctuate. The management of limiting resources for bark beetles such as Tomicus piniperda, Ips typographus, and Pityogenes chalcographus is discussed and exemplified by a simple population model. The combined effects of cutting and other silvicultural measures on pine weevil (Hylobius abietis) populations and damage are reviewed. The influences of stand structure and size on forest insect populations are discussed using Aradus cinnamomeus and pine shoot moths as examples. Zusammenfassung Waldbau und Insektenprobleme Anderungen in forstlichen Okosystemen und in den zeitlichen und raumlichen Verhaltnissen der Lebensgemeinschaften beeinflussen Insektenpopulationen. Waldbauliche Masnahmen konnen als Storungen oder als determinierende Faktoren in den Okosystemen wirken. Sie konnen die Verbreitung und die durchschnittliche Haufigkeit einer Insektenart bestimmen oder die Charakteristik der Fluktuationen einer Population andern. Die Bedeutung und waldbauliche Behandlung populationsbegrenzender Requisiten wird an den Beispielen der Borkenkafer Tomicus piniperda, Ips typographus und Pityogenes chalcographus erlautert und durch ein einfaches Populationsmodell illustriert. Die kombinierte Wirkung von Holzeinschlag und anderen waldbaulichen Masnahmen auf Vorkommen und schadlichen Fras des Russelkafers Hylobius abietis wird besprochen. Auch Masnahmen, die Grose und Struktur von Bestanden beeinflussen, wirken auf Insektenpopulationen ein, z. B. auf Kiefernrindenwanzen und Knospen- und Triebwickler an Kiefern.

Plantations of rapidly growing trees are becoming increasingly common because the high productivity can enhance local economies, support improvements in educational systems, and generally improve the quality of life in rural communities. Landowners frequently choose to plant nonindigenous species; one rationalization has been that silvicultural productivity is enhanced when trees are separated from their native herbivores and pathogens. The expectation of enemy reduction in nonindigenous species has theoretical and empirical support from studies of the enemy release hypothesis (ERH) in the context of invasion ecology, but its relevance to forestry has not been evaluated. We evaluated ERH in the productive forests of Galicia, Spain, where there has been a profusion of pine plantations, some with the indigenous Pinus pinaster, but increasingly with the nonindigenous P. radiata. Here, one of the most important pests of pines is the indigenous bark beetle, Tomicus piniperda. In support of ERH, attacks by T. piniperda were more than twice as great in stands of P. pinaster compared to P. radiata. This differential held across a range of tree ages and beetle abundance. However, this extension of ERH to forestry failed in the broader sense because beetle attacks, although fewer on P. radiata, reduced productivity of P. radiata more than that of P. pinaster (probably because more photosynthetic tissue is lost per beetle attack in P. radiata). Productivity of the nonindigenous pine was further reduced by the pathogen, Sphaeropsis sapinea, which infected up to 28% of P. radiata but was absent in P. pinaster. This was consistent with the forestry axiom (antithetical to ERH) that trees planted "off-site" are more susceptible to pathogens. Fungal infections were positively correlated with beetle attacks; apparently T. piniperda facilitates S. sapinea infections by creating wounds and by carrying fungal propagules. A globally important component in the diminution of indigenous flora has been the deliberate large-scale propagation of nonnative trees for silviculture. At least for Pinus forestry in Spain, reduced losses to pests did not rationalize the planting of nonindigenous trees. There would be value in further exploration of relations between invasion ecology and the forestry of nonindigenous trees.

The association between Tomicus piniperda L. (Col., Scolytinae) and fungi was studied in a Pinus sylvestris L. forest in Mielec-Mościska. Fungi were isolated from overwintered adult beetles taken from two stands situated in different distance from timber yard. Two media were used for isolation. The results showed great diversity of fungi associated with T. piniperda: 1895 cultures, representing 64 species, were isolated. Penicillia and Hormonema dematioides were the dominant species, found in 20.2% and 17.8% of all beetles, respectively. A frequently isolated ophiostomatoid fungi was Ophiostoma minus. Qualitative and quantitative differences in the mycobiota composition of this insect between two stands were detected. The highest richness and diversity of fungal species appeared in the samples taken from the location where the trees were heavily damaged by shoot-feeding of T. piniperda. Differences were most clear for the pathogenic O. minus, which was a common fungal associate of the insects in this stand.

The association between 11 species of bark beetles (Coleoptera: Scolytinae) and one weevil (Coleoptera: Entiminae) with the pitch canker fungus, Fusarium circinatum Nirenberg and O'Donnell, was determined by crushing beetles on selective medium and histone H3 gene sequencing. Pityophthorus pubescens (Marsham) (25.00%), Hylurgops palliatus (Gyllenhal) (11.96%), Ips sexdentatus (Börner) (8.57%), Hypothenemus eruditus Westwood (7.89%), Hylastes attenuatus Erichson (7.40%), and Orthotomicus erosus (Wollaston) (2.73%) were found to carry the inoculum. In addition, the root weevil Brachyderes incanus L. (14.28%) had the second highest frequency of occurrence of the fungus. The responses of the insects to a range of verbenone doses were tested in field bioassays using funnel traps. Catches of P. pubescens, a species colonizing branch tips of live trees, were significantly reduced in a log-linear dose-dependent relationship. Catches of I. sexdentatus, an opportunistic species normally attacking fresh dead host material, were also gradually reduced with increasing verbenone dose. Catches of Tomicus piniperda L., O. erosus, Dryocoetes autographus (Ratzeburg), H. eruditus, Xyleborus dryographus (Ratzeburg), Hylastes ater (Paykull), Hylurgus ligniperda (F.), H. attenuatus, and B. incanus were not significantly affected by verbenone. The effects of verbenone were consistent with differences in host-age preference. Semiochemical disruption by verbenone in P. pubescens and I. sexdentatus could represent an integrated pest management strategy for the prevention of the spread of pitch canker disease between different stands. However, several species associated with F. circinatum were unaffected by verbenone, not supporting this compound for prevention of the establishment of potential vectors in Northern Spain.

The paper deals with cambioxylophagous insects on Scots pine ( Pinus sylvestris L.) trees. Research was conducted in forest stands growing on steep slopes on the left bank of the Otava River about 1 km north of Pisek. These are nearly unmanaged stands of a special-purpose function with the natural occurrence of Scots pine. In total, twenty standing trees at 60 to 160 years of age that died after the spell of drought in 2003 were analysed. The composition of the community of cambioxylophagous insects was recorded in detail. The frequencies of occurrence of particular insect species were determined. In total, 34 species of cambioxylophagous insects were recorded. The order Coleoptera was quite a dominant group and within the order bark beetles (Scolytidae) and longhorn beetles (Cerambycidae) prevailed. The median of the species developing on one tree was 11. Tomicus piniperda (L.) was markedly the most frequent species with the frequency of occurrence 90%. Based on the composition of the communities of cambioxylophagous insects the potential importance of the insect in the decline of the analysed Scots pine trees was evaluated. Cambioxylophagous insects probably played a secondary role there.

Methods of spatial distribution of fallen shoots, pruned by pine shoot beetles, and estimation of efficiency of methods based on collection of fallen shoots and used in forecasting of the occurrence of these insects, are presented in this paper. The fallen shoots were distributed in clusters. The distribution was statistically different from random. Relative errors in estimation of shoot-fall density were the smallest in study transects. Early and late autumn and the following spring, after the snow melt, are the optimum seasons for collecting fallen shoots.

Drought and bark-beetle infestation are major and often interconnected drivers of forest dieback and tree death. These two stressors may interact and accelerate forest mortality, since warmer and drier conditions boost beetle attacks and reduce tree growth. However, the way in which drought and bark-beetle infestation interact and affect declining or dying trees is still poorly understood. To disentangle the long-term interaction between the two stressors, we quantified radial growth (basal area increment), resin production, mortality and intrinsic water-use efficiency (iWUE) inferred from wood-carbon isotope discrimination. We compared trees infested and recently killed by two abundant bark beetle species (. Orthotomicus erosus and Tomicus piniperda) with non-infested living trees in a drought-prone Aleppo pine plantation. Growth and iWUE showed similar values in infested and non-infested trees. Since bark-beetle-infested trees did not grow less than non-infested trees, our results did not support the hypothesis of higher costs of resin production at the expense of stem-wood formation. Radial growth was enhanced by cool and wet winter conditions prior to the growing season. However, infested trees showed lower growth responsiveness than did non-infested trees with respect to this climatic driver of growth. Infested trees also showed a lower resin-duct production two years prior to death than non-infested trees. The growth responsiveness to climate should be characterized in bark-beetle-infested trees, since a weak correlation between climate and growth can be regarded as a predisposing factor of infestation-induced tree death. Such reduced responsiveness to climate stress could be linked to the tree vulnerability to beetle attacks in drought-prone forests. © 2015 Elsevier B.V., We sincerely thank José Bellosta and Montserrat Hernández (Zaragoza Forests and Gardens service) for their advice and help in understanding the Aleppo pine dieback studied. This study was supported by projects CGL2008-04847-C02-01 and CGL2011-26654 (Spanish Ministry of Economy and Competitiveness). We thank the Spanish Meteorological Agency for providing climate data.

The species composition and virulence of fungi associated with Tomicus piniperda were studied at eight locations in Poland. The fungi were isolated from phloem and sapwood samples taken from insect galleries and then identified. The virulence of the most common ophiostomatoid species was evaluated through inoculations using two-year-old Scots pine seedlings. A great diversity of fungi were found associated with T. piniperda, including 4 837 cultures and 67 species. The most important groups of fungi were the ophiostomatoids and moulds, including mainly Penicillium, Trichoderma and Mucor species. Among ophiostomatoid fungi, Ophiostoma minus and O. piceae dominated, with a frequency of occurrence of 32.4 and 11.5% of inspected galleries, respectively. Occasionally isolated species included Leptographium lundbergii, L. procerum, L. wingfieldii, Graphium pycnocephalum and Graphium sp. 'W'. In general, the frequency of the ophiostomatoid species was highly variable among locations. Leptographium wingfieldii and O. minus, were the only species capable of killing whole plants and penetrated deeper into the sapwood than other species (87-100% mortality during the 11 week incubation period). Other fungi, including O. piliferum, O. piceae and L. procerum, were considerably less virulent. associated fungi / Leptographium / Ophiostoma / Pinus sylvestris / Tomicus piniperda / virulence

International audience; A parallel study of the genetic structure of two oligophagous species associated with the same hosts was conducted to determine the main factors shaping the distribution of genetic diversity. The bark beetle Tomicus piniperda and the pine processionary moth (PPM) Thaumetopoea pityocampa are both associated with the genus Pinus and belong to different guilds (xylophagous vs defoliating species). The PPM is an ectophagous species that feeds on the needles of living trees, whereas T. piniperda is endophagous and bores galleries in the inner bark of weakened trees. Both species were sampled in the main regions of France, and their genetic structure was assessed after genotyping with five microsatellite markers. Populations of the PPM were significantly structured. A pattern of isolation by distance was found when distances were calculated as bypassing the Massif Central, whereas no such pattern could be found with raw geographic distances. On the contrary, most populations of T. piniperda were not differentiated. No effect of host species could be detected in either of the two species. We conclude that the two taxa have contrasting effective dispersal rates per generation, and we hypothesize that this reflects the different selection pressures acting on individual fitness via different strategies of host use.

This study deals with the assessment of increment losses in Scots pine trees caused by the maturation feeding of pine shoot beetles Tomicus piniperda (L.) and T. minor (Hart.) (Col., Scolytidae) in even-aged stands grow - ing during their entire life span within range of the influence of a sawmill and its timber yard. In spring 2004, on three sample plots, 0.2 ha in size, situated 60, 200, and 500 m from the yard, height and dbh of all trees were measured and increment cores were taken from randomly selected sample trees. An agreement between the spatial distribution of losses in tree increments and the distribution of damage to crowns of investigated stands indicated that the losses resulted from the maturation feeding of pine shoot beetles migrating from the sawmill timber yard. Divergence of growth in the about 25-years-old stand indicated the beginning of intensive feeding of beetles in pine shoots with a high level of probability. In comparison with the control stand the basal area losses in stands growing 60 and 200 m from the beetle source amounted to 57% and 46%, respectively. The difference in the height of trees was as large as almost 100%.

We explored how two recently introduced methods to promote biodiversity during the timber harvest in boreal forests - green tree retention and use of fire - may affect damages caused by pine shoot beetles (Tomicus piniperda and Tomicus minor; Col., Scolytinae) in the surrounding pine forests. The experimental design included 24 separate study sites, 3-5 ha each, which were assigned to different treatments according to factorial design. Retention levels included 0, 10, 50 m 3 /ha and uncut controls. Twelve of the sites were burned and thus there were three replicates of each treatment combination. Old and new fallen pine shoots were counted from transects in adjacent pine-dominated forests 2 and 3 years after the treatments. Populations of Tomicus spp. in the sites were monitored using window traps before and after the treatments, and by examining felled sample trees. Numbers of fallen shoots returned to background levels around unburned and burned clearcuts with no retention trees in 3 years after the treatments, but remained still at increased level in burned harvested sites with 10 and 50 m 3 of retained trees per hectare. Numbers of fallen shoots in burned uncut forests increased in one site only, where the fire was intense enough to kill large pine trees, but the damage did not extend outside the burned area. Shoot numbers remained at such low levels (< 18 000 shoots/ ha) in all treatment combinations that growth losses were not likely. Numbers of egg galleries of Tomicus spp. in trees killed by fire were low, indicating that burnings that take place after the swarming of Tomicus beetles create dead wood that is not optimal for the breeding of these pests. We conclude that green tree retention and prescribed use of fire do not automatically affect populations of Tomicus spp. more than traditional forestry operations (thinnings and clearcuttings) do.

Fungi isolated from Tomicus piniperda (L.) galleries in infected trap logs, standing trees, and directly from insects were identified using morphological features and molecular data obtained from the mitochondrial and nuclear DNA region. Identified strains represented Leptographium wingfieldii Morelet, Leptographium procerum (Kendr.) Wingf., Leptographium lundbergii Lag. & Melin sensu Jacobs & Wingfield, Ophiostoma ips (Rumb.) Nannf., Ophiostoma minus (Hedg.) H. & P. Syd., and Sphaeropsis sapinea sensu lato. Leptographium wingfieldii is believed to be a potentially pathogenic introduced fungus, but sequence data suggest a possible connection between it and the teleomorph of Ophiostoma aureum (Robinson-Jeffrey & Davids.) T.C. Harrington (reported from British Columbia and the western United States). Our data also show that the ex-type culture of Leptographium terebrantis Barras & Perry, a species very similar morphologically to L. wingfieldii, also grouped with L. wingfieldii. We also identified strains of Leptographium truncatum (Wingf. & Marasas) Wingf.; this species has been synonymized with L. lundbergii, but our data indicate that these are distinct species, and therefore, the name L. truncatum should be reinstated. We also report the extended presence of L. procerum in Ontario. Previously viewed as a “southern” species frequently associated with pine-root decline diseases, it has been infrequently reported from New York state and but once each from Ontario and Quebec.

The fungus Gremmeniella abietina (Lagerb.) Morelet is widely distributed in the northern hemisphere and causes scleroderris canker in several coniferous species. In Sweden, large areas, mainly with 30- to 40-year-old Scots pine (Pinus sylvestris L.) forests, were attacked by the fungus in 2000. The main aim of this study was to investigate the relationship between tree crown transparency (CT) induced by G. abietina and P. sylvestris tree mortality. Further- more, regeneration-colonization by Tomicus piniperda (L.) was monitored in the investigated stands. Thirty-five perma- nent sample plots were established in five P. sylvestris stands (38-46 years old) infected by G. abietina and located in the central part of Sweden. During the 2 years following the attack, the total tree mortality accounted for 380 trees·ha -1 and 6.2 m 2 ·ha -1 on average in the five stands, corresponding to 35% of the trees and 27% of the basal area at the time of the attack. Galleries with broods of T. piniperda occurred in trees with a CT value higher than 97%. A model was derived for predicting the probability of P. sylvestris tree mortality. The mortality of individual trees was found to be related to CT, position of needle loss within the crown (CTPOS), and tree diameter at breast height. Furthermore, there was an interaction between CT and CTPOS and a tendency for CT and site to interact. For a P. sylvestris tree with a 0.16-m diameter at breast height and a CT value of 90% spread throughout the crown, the model indicated a mortality probability of 0.03. Above this CT value, the probability of mortality increased substantially. For coniferous species, ir- respective of the cause of damage, a CT value of 90%-95% appears to be a critical range; any values greater than this indicate a high probability of mortality. Resume : Le champignon Gremmeniella abietina (Lagerb.) Morelet est present un peu partout dans l'hemisphere Nord et cause le chancre scleroderrien chez plusieurs especes de coniferes. En Suede, de vastes superficies, principalement occu- pees par des forets de pin sylvestre (Pinus sylvestris L.) âgees de 30 a 40 ans, ont ete attaquees par ce champignon en 2000. L'objectif principal de cette recherche consistait a etudier la relation entre l'eclaircissement de la cime (EC) cause par G. abietina et la mortalite des tiges de P. sylvestris. De plus, la colonisation de la regeneration par Tomicus piniperda (L.) a ete suivie dans les peuplements a l'etude. Trente-cinq placettes d'echantillonnage permanentes ont ete etablies dans cinq peuplements de P. sylvestris (âges de 38 a 46 ans) infectes par G. abietina et situes dans la partie centrale de la Suede. Pendant les deux annees qui ont suivi l'attaque, la mortalite totale des arbres atteignait 380 tiges·ha -1 et 6,2 m 2 ·ha -1 en moyenne dans les cinq peuplements, ce qui correspondait a 35 % des tiges et 27 % de la surface terriere au moment de l'attaque. Des galeries avec une progeniture de T. piniperda etaient presentes dans les arbres avec une valeur de EC supe- rieure a 97 %. Un modele a ete derive pour predire la probabilite associee a la mortalite des tiges de P. sylvestris. Les au- teurs ont trouve que la mortalite d'un arbre donne etait reliee a EC, a la position de la perte d'aiguilles dans la cime (ECPOS) et au diametre de l'arbre au DHP. De plus, il y avait une interaction entre EC et ECPOS et une tendance pour EC a inte- ragir avec le site. Pour une tige de P. sylvestris avec un diametre au DHP de 0,16 m et une valeur de EC de 90 % uniforme dans toute la cime, le modele indiquait une probabilite de mortalite de 0,03. Au-dessus de cette valeur de EC, la probabi- lite de mortalite augmentait substantiellement. Pour les especes resineuses, peu importe la cause de dommage, une valeur de EC de 90 %a9 5 %s emble etre un niveau critique au-dessus duquel la probabilite de mortalite est elevee. (Traduit par la Redaction) Sikstrom et al. 867

The storm that struck France on december 26th and 28th 1999 felled 140 million m3 of timber and had a high economic, social and landscape impact. This event offered the opportunity to study large-scale patterns in populations of forest insect pests that would benefit from the abundant breeding material. A large-scale survey was carried out in France in 2000 to sample the most frequently observed species developing on spruce (Ips typographus, Pityogene schalcographus) and pine (Tomicus piniperda, Ips sexdentatus) in 898 locations distributed throughout wind-damaged areas. The local abundance of each species scored on a 0 to 5 scale was analysed using geostatistical estimators to explore the extent and intensity of spatial autocorrelation, and was related to site, stand, and neighbourhood landscape metrics of the forest cover (in particular the interconnection with broadleaf forest patches) found within dispersal distance. All species but I. sexdentatus, which was much less abundant, displayed large-scale spatial dependence and regional variations in abundance. Lower infestation levels per tree (windfalls and standing trees) were observed in stands with a high proportion of wind-damaged trees, which was interpreted as the result of beetles distributing themselves among the available breeding material. More infestations were observed in wind-broken trees as compared to wind-felled trees. More importantly, populations showed significant relationships with the structure of coniferous stands (in particular with the number of coniferous patches). T. piniperda population levels were negatively correlated to the amount of coniferous edge shared with broadleaf forest patches, possibly because of the disruptive effect of non-host volatiles on host-finding processes at the landscape-scale. The differences observed between species regarding patterns and relationships to site, stand, and forest cover characteristics are discussed in relation to the ecological characteristics of each species.

Tomicus piniperda and Hylurgops palliatus colonize susceptible host trees by responding to host-specific odour signals as well as by avoiding volatiles emanating from non-host conifers. In the field, the pine shoot beetle, T. piniperda, responded in high numbers to natural odour sources provided by their host tree, Pinus sylvestris, while the non-host conifers Larix decidua, Picea abies, or Pseudotsuga menziesii were significantly less attractive. In contrast, the spruce bark beetle, Hylurgops palliatus, preferentially responded to its main host, P. abies. Furthermore, T. piniperda attacks on P. sylvestris bolts decreased in presence of bark and wood particles from the non-host P. abies, whereas particles from P. menziesii appeared not to affect T. piniperda attacks. Apparently, tree-specific volatiles act at close range as specific signals that lead to the successful discrimination and colonization of the respective host tree species.

Aim, location Tomicus (Coleoptera, Scolytidae) species are some of the principal pests of Eurasian forest and are represented by three coexisting species in Spain, Tomicus piniperda (Linnaeus, 1758), Tomicus destruens (Wollaston, 1865) and Tomicus minor (Harting, 1834). The distribution of two taxa are unknown as they have until recently been considered separate species. Therefore, we model the potential distribution centres and establish the potential distribution limits of Tomicus species in Iberia. We also assess the effectiveness of different models by comparing predicted results with observed data. These results will have application in forest pest management. Methods Molecular and morphological techniques were used to identify species from 254 specimens of 81 plots. For each plot, a Geographical Information System was used to extract a set of 14 environmental (one topographic, six climatic) and biotic variables (seven host tree distributions). General Additive Models and Ecological Niche Factor Analysis models are applied for modelling and predicting the potential distribution of the three especies of Tomicus. Results The results of both modelling methodologies are in agreement. Tomicus destruens is the predominant species in Spain, living in low and hot areas. Tomicus piniperda occurs in lower frequency and prefers wet and cold areas of north-central Spain. We detected sympatric populations of T. destruens and T. piniperda in Northern coast of Spain, infesting mainly P. pinaster. Tomicus minor is the rarest species, and it occupies a fragmented distribution located in high and wet areas. The remarkable biotic variable is the distribution of P. sylvestris, incorporated into the models of T. destruens and T. piniperda. Main conclusions These results indicate that in wet areas of north-central Spain where T. piniperda occurs (and possibly the high altitudes of the southern mountains), T. destruens has a climatic distribution limit. In the northern border of this area, both species overlap their distributions and some co-occurrences were detected. Tomicus minor potentially occurs in high and wet fragmented areas.

The pine shoot beetle, Tomicus piniperda (L.) (Coleoptera: Scolytidae), was first discovered in North America in 1992, and by the late 1990s it was associated with tree mortality and stand decline throughout southern Ontario. To assess whether this beetle was capable of killing vigorous trees (a primary pest) or would kill only trees already stressed (a secondary pest), we surveyed 43 sites of varying Scots pine (Pinus sylvestris L.), red pine (Pinus resinosa Ait.), and jack pine (Pinus banksiana Lamb.) composition. Specifically, our objective was to determine the relationship between tree and site characteristics and the number of stem and shoot attacks by T. piniperda in southern Ontario. An abundance of recently dead and low-vigour pine trees increased susceptibility of sites to stem and shoot attacks by T. piniperda. Significant negative linear relationships were detected between the number of beetle attacks and the mean height, age, diameter at breast height, basal area, canopy cover, duff depth, and radial growth increments. Pure red pine sites had significantly fewer attacks than sites of pure Scots pine and mixed jack pine, which was attributed to differences in tree vigour and forest management. Tomicus piniperda appears to be a secondary bark beetle in southern Ontario, successfully colonizing only recently dead pine trees or trees suffering from stress.

Ophiostoma galeiforme was described first in 1951 from Larix kaempferi in Scotland, where it was found to be associated with the bark beetles Hy- lurgops palliatus, Dryocoetes autographus, and the am- brosia beetle Trypodendron lineatum. The taxonomy of this fungus has been uncertain because of a lack of sexual structures on the type specimen and con- tamination of a preserved ex-type culture. The aim of this study was to clarify application of the species name, O. galeiforme, by designating an epitype and to consider phylogenetic relationships of the species. Nineteen isolates resembling O. galeiforme from dif- ferent parts of the world were used, including collec- tions from Pinus sylvestris infested with Tomicus pi- niperda in Scotland and the contaminated ex-type culture. Morphological characteristics of isolates from Sweden, South Africa, Scotland, Chile and Aus- tria corresponded well with those originally de- scribed for O. galeiforme, and an isolate from Scot

International audience; The pine shoot beetle Tomicus piniperda is present throughout Eurasia. In Europe, it is considered as a secondary pest that rarely causes tree mortality, while heavy damage is observed in Yunnan Province ( China) where it exhibits a novel aggregative behaviour during shoot attack. To understand why the ecological characteristics of the European and Chinese populations differ so strongly, we conducted an analysis of population genetic structure on 12 populations in Yunnan and one in JiLin using mitochondrial (COI-COII) and nuclear (ITS2 and 28S rDNA) DNA sequences, and compared the results to those obtained in France. We showed that the Yunnan populations differed markedly from French and JiLin populations. For all three markers, the genetic distances measured between the Tomicus from Yunnan and those from France were similar to distances previously observed between species. Similar distances were found between Yunnan and JiLin populations. Conversely, the distances between French and JiLin individuals were substantially lower, falling in the intraspecific range. We concluded that the individuals sampled in Yunnan belong to a new, undescribed species (Tomicus sp. nov.). We also showed that some individuals belong to the species T. brevipilosus that had never been recorded from this region before. Evolution of the genus Tomicus is discussed in the light of these new results

The pine shoot beetle, Tomicus piniperda (Coleoptera: Scolytidae), is an exotic pest of pine in North America. We evaluated blends of semiochemical disruptants, which included nonhost volatiles and verbenone, for their ability to disrupt attraction of T. piniperda to traps baited with the attractant α-pinene and to Scots pine, Pinus sylvestris L., trap logs. In Michigan and in Ontario, Canada, a single blend of nonhost volatiles alone [comprised of 1-hexanol, (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol, 3-octanol, and 1-octen-3-ol] or the nonhost volatile blend combined with verbenone significantly reduced attraction of T. piniperda to attractant-baited traps by 68–77%. Similarly, verbenone plus the nonhost volatile blend or a similar blend without 1-octen-3-ol also significantly reduced attack density of T. piniperda on pine trap logs by 56–74% in both Michigan and Ontario. Although relative responses between the different blends were slightly different between Michigan and Ontario, the recommended opera...

The pine shoot beetle, Tomicus piniperda (L.), is an exotic pest that has become established in North America. Discovered in Ohio in 1992, it has since been found in at least 13 states and parts of Canada. The beetle can cause significant growth loss in pines, and it represents a potential threat to trees in areas where it has not yet become established. To evaluate this threat to native pines, field and laboratory tests were conducted on several common and important southern and western species to determine whether they are acceptable hosts for T. piniperda. Comparisons with Pinus sylvestris L., Scots pine, a preferred natural host for the beetle, were made where possible. Measurements of beetle attack success on southern pine billets showed that Pinus taeda L., Pinus echinata Miller, Pinus elliottii var. elliottii Engelmann, Pinus palustris Miller, and Pinus virginiana Miller (loblolly, shortleaf, slash, longleaf, and Virginia pine, respectively) and two western pines, Pinus ponderosa Lawson and Pinus contorta Douglas (ponderosa and lodgepole pine, respectively), were acceptable for breeding material, but brood production was highly variable. Among the southern pines, P. taeda and P. echinata were susceptible to shoot feeding by T. piniperda, whereas P. elliottii was highly resistant and P. palustris seemed to be virtually immune. Shoot feeding tests on the western pines were conducted only in the laboratory, but there was moderate-to-good survival of adults feeding on both species. It seems that if T. piniperda is introduced into the south and west it will likely establish and may cause some damage to native pines. P. taeda may be affected more than other southern pines because it is the most abundant species, it is readily attacked for brood production, which can result in moderately large broods, and the beetle survives well during maturation feeding on P. taeda shoots.

We investigated host preference of the pine shoot beetle, Tomicus piniperda (L.) (Coleoptera: Scolytidae), in a large-scale field study in 1997 and 1998. This Eurasian pest, first discovered in North America in 1992, is capable of developing and shoot-feeding in many North American pines. We hypothesized, however, that T. piniperda would preferentially colonize Scots pine (Pinus sylvestris L.), a Eurasian species, more frequently than North American red pine (Pinus resinosa Ait.) and jack pine (Pinus banksiana Lamb.). We placed freshly cut Scots, red, and jack pine logs in Scots, red, and jack pine forest stands each year in southwestern Michigan, where T. piniperda populations have been established for several years, and in central and northern Michigan, where T. piniperda populations were low to rare. Following T. piniperda progeny emergence, logs were retrieved and debarked and T. piniperda attack density was determined for each log. Tomicus piniperda colonized 80%–90% of the pine logs in the southwestern Michigan stands compared with 2%–19% of logs in the central Michigan stands. No logs in the northern Michigan stands were colonized by T. piniperda in either year. In the southwestern pine stands, T. piniperda attack densities were significantly greater on Scots pine logs than on jack and red pine logs, regardless of stand species.

1) The pine shoot beetle, Tomicus piniperda (L.) (Coleoptera: Scolytidae), is an exotic pest of pine, Pinus spp., and was first discovered in North America in 1992. 2) Although primary attraction to host volatiles has been clearly demonstrated for T. piniperda, the existence and role of secondary attraction to insect-produced pheromones have been widely debated. 3) Currently, commercial lures for T. piniperda include only the host volatiles α-pinene in North America and α-pinene, terpinolene and (+)-3-carene in Europe. Several potential pheromone candidates have been identified for T. piniperda. 4) We tested various combinations of host volatiles and pheromone candidates in Michigan, U.S.A., and Ontario, Canada, to determine an optimal blend. 5) Attraction of T. piniperda was significantly increased when trans-verbenol(95% pure, 3.2% cis-verbenol content) was added with or without myrtenol to α-pinene or to blends of α-pinene and other kairomones and pheromone candidates. 6) Our results, together with other research demonstrating that trans-verbenol is produced by T. piniperda, support the designation of trans-verbenol as a pheromone for T. piniperda. A simple operational lure consisting of α-pinene and trans-verbenol is recommended for optimal attraction of T. piniperda.

1 After a 1-year, extensive pine looper (Bupalus piniaria) outbreak, plots were laid out to study tree susceptibility to attack, and performance of Tomicus piniperda in pine trees suffering from varying levels of defoliation. 2 Tomicus piniperda was the dominating stem-attacking species among the primary stem colonizers, and 82% of all trees that died had been colonized by T. piniperda. 3 Beetle attacks primarily struck severely defoliated trees, i.e. trees that suffered from 90% to 100% defoliation. 4 Beetle attacks peaked in the second year after cessation of the outbreak, and suppressed trees were both more frequently attacked and more susceptible to beetle attack than intermediate and dominant trees. 5 Trees surviving beetle attacks carried more foliage than trees that did not survive the attacks. 6 A single year of severe defoliation is enough to render pine trees susceptible to secondary pests, such as T. piniperda.

Canningia tomici sp. n. (Microsporidia, Unikaryonidae) infects the midgut epithelium, the gut muscules, Malpighian tubules, connective tissues, adipose tissues and the gonads of the pine shoot beetle, Tomicus piniperda (L.) (Coleoptera, Scolytidae). The infection is present in populations of Tomicus piniperda in Europe and in the United States. Uninucleate oval single spores occur in two sizes: 2.8 ± 0.4 × 1.4 ± 0.4 μm and 3.8 ± 0.3 × 2.0 ± 0.2 μm. The polar filament of this microsporidium is fixed subapically in a flat anchoring disc. The thick posterior lamellae of the binary polaroplast are asymmetric due to the lateral fixation of the polar filament.

The responses of the bark beetle predators Thanasimus femoralis (Zett.) and Thanasimus formicarius (L.) (Col.: Cleridae) to a combination of α-pinene and ethanol, and Pheroprax ® , the aggregation pheromone of Ips typographus (Col.: Scolytidae), were estimated using baited and unbaited flight barrier traps in central Sweden in 1996 and 1998. In addition, the flight periods of the two Thanasimus species were analysed on the basis of trap catches. Egg development and egg loads of T. formicarius were estimated by dissecting females caught on different dates, and counting the number of medium sized and large eggs in the ovaries. T. femoralis was strongly attracted to Pheroprax ® , but almost no individuals were caught in the traps baited with α-pinene and ethanol. In contrast, T. formicarius was strongly attracted to both kinds of baits. The flight periods of the two Thanasimus species were markedly different. T. formicarius initiated flight in early spring, at about the same time as the first bark beetle species, Tomicus piniperda and Hylurgops palliatus , began to fly. The flight period of T. femoralis started later in the spring, at about the same time as that of I. typographus . Medium sized and large eggs were not present in the ovaries of T. formicarius in the beginning of the flight period. Thereafter, during the major part of the flight period, most females carried medium sized eggs while large eggs occurred mainly in the first half of the flight period.