| trap type, chirality of alpha-pinene, and geographic region affect sampling efficiency of root and lower stem insects in pine. | root and lower stem insects cause significant damage to conifers, vector phytopathogenic fungi, and can predispose trees to bark beetle attacks. the development of effective sampling techniques is an important component in managing these cryptic insects. we tested the effects of trap type and stereochemistry of alpha-pinene, in combination with ethanol, on catches of the root colonizing weevils (coleoptera: curculionidae) hylobius spp. [mostly hylobius pales (herbst)], and pachylobius picivorus ... | 2001 | 11681673 |
| leptographium wingfieldii introduced into north america and found associated with exotic tomicus piniperda and native bark beetles. | leptographium wingfieldii is a well-known fungal associate of the pine shoot beetle, tomicus piniperda, in europe. this fungus is pathogenic to pines and is an important cause of blue-stain in the sapwood of infested trees. tomicus piniperda was first found in a christmas tree plantation in ohio, usa, 1992, but isolation of the fungi associated with these intercepted insects was not attempted. fungal strains resembling l. wingfieldii were recently isolated from pines attacked by t. piniperda, de ... | 2004 | 15209281 |
| response to host volatiles by native and introduced populations of dendroctonus valens (coleoptera: curculionidae, scolytinae) in north america and china. | bark beetles (coleoptera: curculionidae, scolytinae) have specialized feeding habits, and commonly colonize only one or a few closely related host genera in their geographical ranges. the red turpentine beetle, dendroctonus valens leconte, has a broad geographic distribution in north america and exploits volatile cues from a wide variety of pines in selecting hosts. semiochemicals have been investigated for d. valens in north america and in its introduced range in china, yielding apparent region ... | 2007 | 17160720 |
| cross-attraction between an exotic and a native pine bark beetle: a novel invasion mechanism? | aside from the ecological impacts, invasive species fascinate ecologists because of the unique opportunities that invasives offer in the study of community ecology. some hypotheses have been proposed to illustrate the mechanisms that allow exotics to become invasive. however, positive interactions between exotic and native insects are rarely utilized to explain invasiveness of pests. | 2007 | 18074026 |
| leptographium sinoprocerum sp. nov., an undescribed species associated with pinus tabuliformis-dendroctonus valens in northern china. | during a study of ophiostomatoid fungi associated with the invasive pest dendroctonus valens in the pinus tabuliformis ecosystem in northern china, a multigenic (its2-lsu, beta-tubulin and ef1-alpha) phylogenetic analysis and examination of morphological features revealed in addition to leptographium procerum the occurrence of an undescribed species. the new species, leptographium sinoprocerum, belongs to the l. procerum-l. profanum clade. both l. procerum and l. sinoprocerum are similar to each ... | 2008 | 18592901 |
| electrophysiological and behavioral responses of dendroctonus valens (coleoptera: curculionidae: scolytinae) to four bark beetle pheromones. | the red turpentine beetle, dendroctonus valens leconte (coleoptera: curculionidae: scolytinae), has caused extensive mortality of pinus tabuliformis carrière in north central china. the electrophysiological and behavioral activities of the four bark beetle pheromones, frontalin, exo-brevicomin, trans-verbenol, and cis-verbenol, singly or in combination with host-produced kairomones, were tested on red turpentine beetles. both sexes showed a consistent electrophysiological response to the four te ... | 2009 | 19389297 |
| ophiostomatoid fungi (ascomycota) associated with pinus tabuliformis infested by dendroctonus valens (coleoptera) in northern china and an assessment of their pathogenicity on mature trees. | dendroctonus valens is an invasive pest in coniferous forests of northern china. it was suspected of being responsible for the death of more than three million pinus tabuliformis trees. the present study sought to identify the ophiostomatoid fungi associated with d. valens in northern china and understand the possible role of these fungi in the pine decline. on the basis of morphology, physiology, mating compatibility and phylogenetic analyses of multiple dna sequences, seven species of ophiosto ... | 2009 | 19404768 |
| bacterial community and nitrogen fixation in the red turpentine beetle, dendroctonus valens leconte (coleoptera: curculionidae: scolytinae). | the red turpentine beetle, dendroctonus valens leconte (coleoptera: curculionidae: scolytinae), colonizes all pines species within its native range throughout north and central america. recently, this species was accidentally introduced to china, where it has caused severe damage in pine forests. it belongs to a group of beetles that spend most of their lives between the tree bark and sapwood, where it feeds on phloem: a poor substrate with very low nutritional value of nitrogen and toxic proper ... | 2009 | 19543937 |
| threat and management strategies of potentially invasive insects in china. | the global invasive species database, gisd, comprises 27 species of the most significant invasive alien insects in the world (through november, 2005), 6 of which are originally native to china, 11 are established in china, and 10 have a potential invasion threat to china. this paper discusses these species in terms of distribution, harmfulness and dispersal ways, and finds that: (i) information regarding invasive insects in the gisd remains inadequate. such harmful invasive species as opogona sa ... | 2009 | 19911125 |
| application of semiochemicals to assess the biodiversity of subcortical insects following an ecosystem disturbance in a sub-boreal forest. | from 2000 through 2003 we used semiochemical-baited traps in northeastern minnesota, usa, to assess changes in assemblages of subcortical forest insects after a catastrophic wind storm in 1999 and subsequent (1999-2000) fuel-reduction activities (salvage-logging and prescribed-burning). we determined the regional efficacy of fifteen semiochemical blends (pheromones and kairomones) as attractants for target and non-target subcortical insect species (coleoptera: anthribidae, buprestidae, cerambyci ... | 2009 | 20066478 |
| geographic variation in bacterial communities associated with the red turpentine beetle (coleoptera: curculionidae). | bacterial communities are known to play important roles in insect life histories, yet their consistency or variation across populations is poorly understood. bacteria associated with the bark beetle dendroctonus valens leconte from eight populations, ranging from wisconsin to oregon, were evaluated and compared. we used the culture-independent technique of denaturing gradient gel electrophoresis to visualize bacterial diversity, or individual operational taxonomic units (otus), from individual b ... | 2010 | 20388269 |
| complex interactions among host pines and fungi vectored by an invasive bark beetle. | *recent studies have investigated the relationships between pairs or groups of exotic species to illustrate invasive mechanisms, but most have focused on interactions at a single trophic level. *here, we conducted pathogenicity tests, analyses of host volatiles and fungal growth tests to elucidate an intricate network of interactions between the host tree, the invasive red turpentine beetle and its fungal associates. *seedlings inoculated with two strains of leptographium procerum isolated from ... | 2010 | 20546136 |
| immunocompetence of the red turpentine beetle, dendroctonus valens leconte (coleoptera: curculionidae, scolytinae): variation between developmental stages and sexes in populations in china. | immune defense imposes fitness costs as well as benefits, so organisms should optimize, not maximize, their immune function through their life cycle. we investigated this issue in the red turpentine beetle, dendroctonus valens leconte (coleoptera: curculionidae, scolytinae), which is a pine-killing invasive beetle in china, though it is usually considered as a secondary pest in its native range of north america. we hypothesized that pathogen pressure may affect these beetles differently througho ... | 2010 | 20615412 |
| antennal morphology and sensilla ultrastructure of dendroctonus valens leconte (coleoptera: curculionidae, seolytinae), an invasive forest pest in china. | dendroctonus valens leconte, an invasive forest pest, is highly dependent on its olfactory system for activities such as host seeking, mating, oviposition and population aggregation. the antennae are the primary olfactory organs in bark beetles. we describe four morphological types of sensilla on the antenna of d. valens: (1) 3 subtypes of sensilla trichodea located at the apex and lateral surface of the club. sensilla trichodea types 1 and 3 were innervated by 5 and 13 dendrites, respectively. ... | 2010 | 20643555 |
| mutual interactions between an invasive bark beetle and its associated fungi. | interactions between invasive insects and their fungal associates have important effects on the behavior, reproductive success, population dynamics and evolution of the organisms involved. the red turpentine beetle (rtb), dendroctonus valens leconte (coleoptera: scolytinae), an invasive forest pest in china, is closely associated with fungi. by carrying fungi on specialized structures in the exoskeleton, rtb inoculates fungi in the phloem of pines (when females dig galleries for egg laying and w ... | 2011 | 21777500 |
| responses of bark beetle-associated bacteria to host monoterpenes and their relationship to insect life histories. | bark beetles that colonize living conifers and their microbial associates encounter constitutive and induced chemical defenses of their host. monoterpene hydrocarbons comprise a major component of these allelochemicals, and many are antibiotic to insects, fungi, and bacteria. some bark beetle species exhaust these defenses by killing their host through mass attacks mediated by aggregation pheromones. others lack adult aggregation pheromones and do not engage in pheromone-mediated mass attacks, b ... | 2011 | 21710365 |
| antennal transcriptome analysis of odorant reception genes in the red turpentine beetle (rtb), dendroctonus valens. | the red turpentine beetle (rtb), dendroctonus valens leconte (coleoptera: curculionidae, scolytinae), is a destructive invasive pest of conifers which has become the second most important forest pest nationwide in china. dendroctonus valens is known to use host odors and aggregation pheromones, as well as non-host volatiles, in host location and mass-attack modulation, and thus antennal olfaction is of the utmost importance for the beetles' survival and fitness. however, information on the genes ... | 2015 | 25938508 |
| yeast diversity associated with invasive dendroctonus valens killing pinus tabuliformis in china using culturing and molecular methods. | bark beetle-associated yeasts are much less studied than filamentous fungi, yet they are also considered to play important roles in beetle nutrition, detoxification, and chemical communication. the red turpentine beetle, dendroctonus valens, an invasive bark beetle introduced from north america, became one of the most destructive pests in china, having killed more than 10 million pinus tabuliformis as well as other pine species. no investigation of yeasts associated with this bark beetle in its ... | 2014 | 24691849 |
| putative origins of the fungus leptographium procerum. | appropriate management of invasive fungi requires adequate understanding of their global diversities and movement histories. the fungus leptographium procerum is associated with root-colonizing forest insects in pine forests throughout the world, and may have contributed to the aggressive behaviour of the red turpentine beetle (dendroctonus valens) in the beetle's invasive range in china. we used microsatellites and mating type loci to investigate the global diversity of l. procerum and the sour ... | 2017 | 28007219 |
| taxonomy and phylogeny of the leptographium procerum complex, including leptographium sinense sp. nov. and leptographium longiconidiophorum sp. nov. | leptographium procerum (ophiostomatales, ascomycota) is a well-known fungal associate of pine root-infesting bark beetles and weevils, occurring in several countries of the world. the fungus is not a primary pathogen but has been associated with white pine root decline in the usa and with serious damage caused by the introduced red turpentine beetle (rtb) dendroctonus valens in china. several species closely related to l. procerum have been described during the past decade. the aim of this study ... | 2015 | 25510728 |
| large shift in symbiont assemblage in the invasive red turpentine beetle. | changes in symbiont assemblages can affect the success and impact of invasive species, and may provide knowledge regarding the invasion histories of their vectors. bark beetle symbioses are ideal systems to study changes in symbiont assemblages resulting from invasions. the red turpentine beetle (dendroctonus valens) is a bark beetle species that recently invaded china from its native range in north america. it is associated with ophiostomatalean fungi in both locations, although the fungi have ... | 2013 | 24205124 |
| do novel genotypes drive the success of an invasive bark beetle-fungus complex? implications for potential reinvasion. | novel genotypes often arise during biological invasions, but their role in invasion success has rarely been elucidated. here we examined the population genetics and behavior of the fungus, leptographium procerum, vectored by a highly invasive bark beetle, dendroctonus valens, to determine whether genetic changes in the fungus contributed to the invasive success of the beetle-fungal complex in china. the fungus was introduced by the beetle from the united states to china, where we identified seve ... | 2011 | 22164824 |
| nitrogen-fixing and uricolytic bacteria associated with the gut of dendroctonus rhizophagus and dendroctonus valens (curculionidae: scolytinae). | the bark beetles of the genus dendroctonus feed on phloem that is a nitrogen-limited source. nitrogen fixation and nitrogen recycling may compensate or alleviate such a limitation, and beetle-associated bacteria capable of such processes were identified. raoultella terrigena, a diazotrophic bacteria present in the gut of dendroctonus rhizophagus and d. valens, exhibited high acetylene reduction activity in vitro with different carbon sources, and its nifh and nifd genes were sequenced. bacteria ... | 2013 | 23525792 |
| invasive bark beetle-associated microbes degrade a host defensive monoterpene. | conifers respond to herbivore attack with defensive chemicals, which are toxic to both insects and their associated microorganisms. microorganisms associated with insects have been widely reported to metabolize toxic chemicals, which may help both microorganisms and host insects overcome host conifer defense. dendroctonus valens leconte, an introduced exotic pest from north america to china, has killed millions of healthy pines. alpha-pinene is the most abundant defensive monoterpene in chinese ... | 2016 | 26224144 |
| comparison of orthologous cytochrome p450 genes relative expression patterns in the bark beetles dendroctonus rhizophagus and dendroctonus valens (curculionidae: scolytinae) during host colonization. | bark beetles of the genus dendroctonus are important components of coniferous forests. during host colonization, they must overcome the chemical defences of their host trees, which are metabolized by cytochrome p450 (cyp or p450) enzymes to compounds that are readily excreted. in this study, we report the relative expression (quantitative real-time pcr) of four orthologous cytochrome p450 genes (cyp6bw5, cyp6dg1, cyp6dj2 and cyp9z20) in dendroctonus rhizophagus and dendroctonus valens forced to ... | 2015 | 26537737 |
| predicting north american scolytinae invasions in the southern hemisphere. | scolytinae species are recognized as one of the most important tree mortality agents in coniferous forests worldwide, and many are known invaders because they are easily transported in wood products. nonnative trees planted in novel habitats often exhibit exceptional growth, in part because they escape herbivore (such as scolytinae) pressure from their native range. increasing accidental introductions of forest pest species as a consequence of international trade, however, is expected to diminis ... | 2017 | 28052506 |
| pine defensive monoterpene α-pinene influences the feeding behavior of dendroctonus valens and its gut bacterial community structure. | the exposure to plant defense chemicals has negative effects on insect feeding activity and modifies insect gut microbial community composition. dendroctonus valens is a very destructive forest pest in china, and harbors a large diversity and abundance of gut microorganisms. host pine defensive chemicals can protect the pines from attack by the holobiont. in this study, boring length of d. valens feeding on 0 mg/g α-pinene and 9 mg/g α-pinene concentration in phloem media for 6 and 48 h were rec ... | 2016 | 27809267 |
| sexual variation of bacterial microbiota of dendroctonus valens guts and frass in relation to verbenone production. | gut microbiota are widely involved in insect biology, and many factors can influence the microbiota in guts and frass. dendroctonus valens is a very destructive forest pest in china, and the mass-attacking behavior is regulated by several semiochemicals, including verbenone, a multifunctional pheromone. the beetle harbors a variety of bacteria in its guts and frass and some of them are capable of verbenone production. d. valens is characterized by monogamy and female-initiated attacking behavior ... | 2016 | 27677696 |
| sound-triggered production of antiaggregation pheromone limits overcrowding of dendroctonus valens attacking pine trees. | for insects that aggregate on host plants, both attraction and antiaggregation among conspecifics can be important mechanisms for overcoming host resistance and avoiding overcrowding, respectively. these mechanisms can involve multiple sensory modalities, such as sound and pheromones. we explored how acoustic and chemical signals are integrated by the bark beetle dendroctonus valens to limit aggregation in china. in its native north american range, this insect conducts nonlethal attacks on weake ... | 2017 | 27707752 |
| contributions by host trees and insect activity to bacterial communities in dendroctonus valens (coleoptera: curculionidae) galleries, and their high overlap with other microbial assemblages of bark beetles. | bark beetles are associated with a diversity of symbiotic microbiota that can mediate interactions with their host plants. dendroctonus valens leconte is a widely distributed bark beetle in north and central america, and initiates solitary attacks on several species of pinus in the great lakes region. in this study, we aimed to further characterize the bacterial community associated with d. valens feeding galleries using next-generation sequencing, and the possible contributions of both tree-res ... | 2016 | 26721298 |
| gut-associated bacteria of dendroctonus valens and their involvement in verbenone production. | bark beetles are the most important mortality agent in coniferous forests, and pheromones play important roles in their management. dendroctonus valens leconte was introduced from north america to china and has killed millions of healthy pines there. trapping with semiochemicals and pheromones was deployed in d. valens management in the last decade, but little is known about the ability of gut bacteria to produce the pheromone. in this study, we analyzed the volatiles in d. valens guts and frass ... | 2015 | 25985770 |
| areas of potential suitability and survival of dendroctonus valens in china under extreme climate warming scenario. | the areas in china with climates suitable for the potential distribution of the pest species red turpentine beetle (rtb) dendroctonus valens leconte (coleoptera: scolytidae) were predicted by climex based on historical climate data and future climate data with warming estimated. the model used a historical climate data set (1971-2000) and a simulated climate data set (2010-2039) provided by the tyndall centre for climate change (tyn sc 2.0). based on the historical climate data, a wide area was ... | 2015 | 25895594 |
| what is the password? female bark beetles (scolytinae) grant males access to their galleries based on courtship song. | acoustic signals are commonly used by insects in the context of mating, and signals can vary depending on the stage of interaction between a male and female. while calling songs have been studied extensively, particularly in the orthoptera, much less is known about courtship songs. one outstanding question is how potential mates are differentiated by their courtship signal characteristics. we examined acoustic courtship signals in a new system, bark beetles (scolytinae). in the red turpentine be ... | 2015 | 25783802 |
| the pheromone frontalin and its dual function in the invasive bark beetle dendroctonus valens. | the red turpentine beetle, dendroctonus valens leconte, is one of the most destructive invasive forest pests in china, having killed more than 6 million pines since its first outbreak in 1999. little is known about d. valens pheromone biology and no aggregation pheromone has yet been identified. analysis by gas chromatograph/mass spectrometer of volatiles collected from live beetles in china showed that female beetles produce frontalin and males do not. olfactory assays in the laboratory showed ... | 2013 | 23629623 |
| diversity and expression of p450 genes from dendroctonus valens leconte (curculionidae: scolytinae) in response to different kairomones. | bark beetles (curculionidae: scolytinae) are major cause of woody plants death in the world. they colonize the stem and other parts of trees recognizing host-produced specific compounds (kairomones) and insect pheromones. bark beetle's antennae and alimentary canal participate in the host selection identifying chemical compounds produced by trees and insects, and also in the metabolism and detoxification of these compounds. the red turpentine beetle (rtb), dendroctonus valens leconte, is an unag ... | 2013 | 23454142 |
| saccharide-mediated antagonistic effects of bark beetle fungal associates on larvae. | bark beetles are among the most destructive of pine forest pests and they form close symbiotic relationships with ophiostomatoid fungi. although some fungi are considered to be mutualistic symbionts of bark beetles with respect to the supply of nutrients, detrimental effects of fungal symbionts on larval growth have also been frequently reported. the mechanisms of such antagonistic effects are hypothesized to be a decrease in nutritional resources caused by competition for saccharides by the fun ... | 2013 | 23193043 |
| red turpentine beetle: innocuous native becomes invasive tree killer in china. | the red turpentine beetle (rtb), dendroctonus valens leconte (coleoptera: curculionidae: scolytinae), is a secondary pest of pines in its native range in north and central america. outbreaks and tree mortality attributed to rtb alone are rare in its native range. rtb was introduced into china in the early 1980s and spread rapidly from shanxi province to four adjacent provinces; it has infested over 500,000 ha of pine forest and has caused extensive tree mortality since 1999. we provide a histori ... | 2013 | 22994548 |
| monoterpene variation mediated attack preference evolution of the bark beetle dendroctonus valens. | several studies suggest that some bark beetle like to attack large trees. the invasive red turpentine beetle (rtb), dendroctonus valens leconte, one of the most destructive forest pests in china, is known to exhibit this behavior. our previous study demonstrated that rtbs preferred to attack large-diameter trees (diameter at breast height, dbh ≥30 cm) over small-diameter trees (dbh ≤10 cm) in the field. in the current study, we studied the attacking behavior and the underlying mechanisms in the ... | 2011 | 21811555 |
| quantitative variation and biosynthesis of hindgut volatiles associated with the red turpentine beetle, dendroctonus valens leconte, at different attack phases. | the red turpentine beetle (rtb), dendroctonus valens leconte, is a destructive invasive forest pest in china. for such tree-killing species, how to initiate a volatile-mediated mass attack is of great importance during the course of establishment. to understand the hindgut volatile production mechanism underlying mass attack initiated by rtb, coupled gas chromatography-mass spectrometry and 13c-labelled precursors were applied to explore the quantitative variation and biosynthesis of volatiles a ... | 2010 | 19671207 |
| maintenance of midgut epithelial cells from dendroctonus valens (coleoptera: scolytidae) in vitro. | this article describes the culture of epithelial cells from anterior and posterior midgut regions of adult dendroctonus valens. culture conditions were established, and cell adherence was improved by means of a new technique that allowed the cells to grow between two glass coverslips. cytoplasmic projections occur as anterior midgut cells grow to confluence; these projections were not observed in cells of the posterior midgut. the optimal culture medium for the maintenance of these epithelial ce ... | 2006 | 15180434 |
| response of some scolytids and their predators to ethanol and 4-allylanisole in pine forests of central oregon. | lindgren multiple funnel traps were set up in pine forests of central oregon to determine the response of scolytid bark beetles to ethanol and 4-allylanisole (4aa). traps were baited with two release rates of ethanol (4.5 or 41.4 mg/hr) and three release rates of 4aa (0, 0.6, or 4.3 mg/hr) in a 2 x 3 factorial design. all traps also released a 1:1 mixture of alpha- and beta-pinene at 11.4 mg/hr. of 13,396 scolytids caught, dendroctonus valens made up 60%, hylurgops spp. 18.5%, ips spp. 16%, hyla ... | 2001 | 11446294 |
| stereospecific antennal response by red turpentine beetle,dendroctonus valens to chiral monoterpenes from ponderosa pine resin. | the antennal response ofdendroctonus valens to host monoterpenes from the resin of ponderosa pine was studied using the electroantennogram (eag) technique. male and female beetles were given a single dose of each of 11 different monoterpenes. response amplitude to the different compounds did not vary between sexes and was generally well correlated with results from field attraction studies. response to (s)-(-)-β-pinene was greatest. the relative amplitude of the responses to the (r)-(+) and (s)- ... | 1993 | 24248569 |
| chiral specificity in responses by the bark beetledendroctonus valens to host kairomones. | the attraction of the red turpentine beetle,dendroctonus valens, to the resin volatiles of its host,pinus ponderosa, is elicited by three chiral monoterpenes. in field assays response was greatest to (s)-(-)-β-pinene; 92% (s)-(-)-α-pinene found inp ponderosa resin was not attractive. however, 75% (r)-(+)-α-pinene, which occurs inpinus lambertiana, a sympatric host ofd. valens, was attractive. (s)-(-)-α-pinene interrupted response to (r)-(+)-α-pinene. (s)-(+)-3-carene from both hosts was attracti ... | 1993 | 24249362 |
| volatile compounds in the larval frass ofdendroctonus valens anddendroctonus micans (coleoptera: scolytidae) in relation to oviposition by the predator,rhizophagus grandis (coleoptera: rhizophagidae). | during a laboratory study evaluatingrhizophagus grandis (a specific native predator of the eurasian bark beetle,dendroctonus micans), as a potential biocontrol agent against the north american bark beetle,dendroctonus valens, it was found that feeding larvae and laboratory-produced frass of the potential prey elicited very high oviposition responses in the predator. comparative chemical analysis of this laboratory-produced larval frass revealed that one major volatile compound, (-)-fenchone, is ... | 1991 | 24258494 |