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Felix A. H. Sperling - One of the best experts on this subject based on the ideXlab platform.
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Genus delimitation, biogeography and diversification of Choristoneura Lederer (Lepidoptera: Tortricidae) based on molecular evidence
Systematic Entomology, 2018Co-Authors: Giovanny Fagua, Fabien L. Condamine, Jason J. Dombroskie, Bong-kyu Byun, Jurate De Prins, Thomas J. Simonsen, Marcos Báez, Bryan M. T. Brunet, Felix A. H. SperlingAbstract:Widely known for pest species that include major modulators of temperate forests, the genus Choristoneura is part of the species-rich tribe Archipini of leafroller moths (Tortricidae). Delimitation of the genus has remained unresolved because no phylogeny has included species endemic to Africa and studies have often omitted the type species of the genus. Further taxonomic confusion has been generated by the transfer of Archips occidentalis (Walsingham) to Choristoneura, creating a homonym with Choristoneura occidentalis Freeman, an important defoliator of North American forests. To define the limits of the genus, we reconstructed a phylogeny using DNA sequences for mitochondrial cytochrome oxidase subunit I and nuclear ribosomal 28S genes. Our ingroup included 23 Choristoneura species-level taxa, complemented by a large sample of outgroups comprising 82 species of Archipini and other Tortricidae. We generated a time-calibrated tree using fossil and secondary calibrations and we inferred biogeographic and diversification processes in Choristoneura. Our analysis recovered the genus as polyphyletic, with Archips occidentalis, Choristoneura simonyi and Choristoneura evanidana excluded from the main clade. Based on the recovered phylogenies and a redefinition, we restrict Choristoneura primarily to species with a northern hemisphere distribution. Our analysis supports A. occidentalis as the sister group of Cacoecimorpha pronubana, C. simonyi as the sister of ‘Xenotemna’ pallorana, and C. evanidana as the sister of Archips purpurana. A new combination is proposed: Archips evanidana comb.n.; the availability of ‘Xenotemna’ as a valid name is discussed and A. occidentalis is considered as an orphaned name within the Archipini. We found support for a Holarctic origin of Choristoneura about 23 Ma, followed by early divergence in the Palearctic region. The main divergence occurred at 16Ma, with one clade in the Nearctic and another in the Palearctic. Subsequent cladogenetic events were synchronous and related to herbivorous specialization, with each clade divided into coniferophagous and polyphagous lineages. Their specialization as conifer feeders temporally matched the expansion of boreal forest during the Miocene.
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Convergent herbivory on conifers by Choristoneura moths after boreal forest formation.
Molecular phylogenetics and evolution, 2018Co-Authors: Giovanny Fagua, Fabien L. Condamine, Bryan M. T. Brunet, Anne-laure Clamens, Jérôme Laroche, Roger C. Levesque, Michel Cusson, Felix A. H. SperlingAbstract:Abstract Mitogenomes are useful markers for phylogenetic studies across a range of taxonomic levels. Here, we focus on mitogenome variation across the tortricid moth genus Choristoneura and particularly the spruce budworm (Choristoneura fumiferana) species complex, a notorious pest group of North American conifer forests. Phylogenetic relationships of Tortricidae, representing two subfamilies, four tribes and nine genera, were analyzed using 21 mitogenomes. These included six newly-sequenced mitogenomes for species in the spruce budworm complex plus three additional Choristoneura species and 12 previously published mitogenomes from other tortricids and one from the Cossidae. We evaluated the phylogenetic informativeness of the mitogenomes and reconstructed a time-calibrated tree with fossil and secondary calibrations. We found that tortricid mitogenomes had conserved protein and ribosomal regions, and analysis of all protein-coding plus ribosomal genes together provided an efficient marker at any taxonomic rank. The time-calibrated phylogeny showed evolutionary convergence of conifer feeding within Choristoneura, with two independent lineages, the Nearctic spruce budworm complex and the Palearctic species Choristoneura murinana, both shifting onto conifers about 11 million years ago from angiosperms. These two host-plant shifts both occurred after the formation of boreal forest in the late Miocene. Haplotype diversification within the spruce budworm complex occurred in the last 4 million years, and is probably linked to the initial cooling cycles of the Northern Hemisphere in the Pliocene.
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Identification and ecological characterisation of Choristoneura occidentalis (Lepidoptera: Tortricidae) populations in southwestern Alberta, Canada
Canadian Entomologist, 2013Co-Authors: Bryan M. T. Brunet, Anina E. Hundsdoerfer, Felix A. H. SperlingAbstract:The western spruce budworm, Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae), is an important pest of western North American coniferous forests, where its principal larval host is Rocky Mountain Douglas-fir, Pseudotsuga menziesii subspecies glauca (Beissner) Murray (Pinaceae). In southwestern Alberta, Canada, populations were recently discovered feeding on an unconventional host, an Engelmann spruce, Picea engelmannii Parry ex. Engelmann 3white spruce, Picea glauca (Moench) Voss hybrid (Pinaceae), in a transition zone between the two major forest types characterised by these conifer species. We use molecular evidence to verify the species identity of outbreaking Choristoneura populations collected from Douglas-fir and hybrid spruces in southwestern Alberta in 2009, and characterise the larval and male moth phenology. Both mito- chondrial and microsatellite markers confirmed these populations as C. occidentalis, but admixture with Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) was detected in some individuals. Few differences associated with separate host trees were evident in the phenology of larvae and the flight period of male moths. Resume´—La tordeuse occidentale de l'epinette, Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae) est un ravageur important des forets de coniferes de l'Ouest de l'Amerique du Nord, ou` son hote larvaire principal est le sapin bleu de Douglas, Pseudotsuga menziesii sous-especeglauca (Beissner) Murray (Pinaceae). Dans le sud-ouest de l'Alberta, Canada, des populations ont recemment eteobservees en train de se nourrir sur un hote inusite´, un hybride de l'epinette d'Engelmann, Picea engelmannii Parry ex. Engelmann, x epinette blanche, Picea glauca (Moench) Voss (Pinaceae), dans une zone de transition entre les deux types majeurs de foret caracterises par ces especes de coniferes. Des donnees moleculaires nous ont servi a erifier l'identitedes especes emiques de Choristoneura recoltees sur les sapins de Douglas et les epinettes hybrides dans le sud-ouest de l'Alberta en 2009 et ad ecrire la phenologie des larves et des papillons adultes males. Tant les marqueurs mitochondriaux que microsatellites confirment que ces populations sont des C. occidentalis, mais un melange avec Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) a eted ecelechez certains individus. Il y a peu de differences dans la phenologie des larves et la periode de vol des adultes en fonction des differents arbres-hotes.
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Identification and ecological characterisation of Choristoneura occidentalis (Lepidoptera: Tortricidae) populations in southwestern Alberta, Canada
The Canadian Entomologist, 2013Co-Authors: Bryan M. T. Brunet, Anina E. Hundsdoerfer, Felix A. H. SperlingAbstract:AbstractThe western spruce budworm, Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae), is an important pest of western North American coniferous forests, where its principal larval host is Rocky Mountain Douglas-fir, Pseudotsuga menziesii subspecies glauca (Beissner) Murray (Pinaceae). In southwestern Alberta, Canada, populations were recently discovered feeding on an unconventional host, an Engelmann spruce, Picea engelmannii Parry ex. Engelmann × white spruce, Picea glauca (Moench) Voss hybrid (Pinaceae), in a transition zone between the two major forest types characterised by these conifer species. We use molecular evidence to verify the species identity of outbreaking Choristoneura populations collected from Douglas-fir and hybrid spruces in southwestern Alberta in 2009, and characterise the larval and male moth phenology. Both mitochondrial and microsatellite markers confirmed these populations as C. occidentalis, but admixture with Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) was detected in some individuals. Few differences associated with separate host trees were evident in the phenology of larvae and the flight period of male moths.
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Characterization of EST-based SSR loci in the spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae)
Conservation Genetics Resources, 2013Co-Authors: Bryan M. T. Brunet, D. Doucet, Brian R. Sturtevant, Felix A. H. SperlingAbstract:After identifying 114 microsatellite loci from Choristoneura fumiferana expressed sequence tags, 87 loci were assayed in a panel of 11 wild-caught individuals, giving 29 polymorphic loci. Further analysis of 20 of these loci on 31 individuals collected from a single population in northern Minnesota identified 14 in Hardy-Weinberg equilibrium.
Donal A. Hickey - One of the best experts on this subject based on the ideXlab platform.
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amplified mitochondrial dna as a diagnostic marker for species of conifer feeding Choristoneura lepidoptera tortricidae
Canadian Entomologist, 1995Co-Authors: Felix A. H. Sperling, Donal A. HickeyAbstract:The Canadian Entomologist 127: 277-288 (1995) We descrihe a method for identifying conifer-feeding species and lineages of Ckoristoneura Lederer in Canada and Alaska. The method relies on amplification of mitochondrial (mt) DNA by thc polymerase chain reaction (PCR): amplified DNA is then digested with restriction enzymes to give characteristic DNA fragment patterns. We used the cytochrome oxidase I and I1 genes of mtDNA, which were previousiy shown to contain numerous nucleotide differences at the level of species. Ten restriction enzymes were surveyed and a combination of two of these (Ec40R V + Ninf I) was sufficient to distinguish rhc major mtDNA lineages. Chorisroncrrra firmiferana (Clemens), C. pitllis Freeman, and C. rnsacenna (Harris) were readily distinguished fromeach other and froman assemblage of three putative western species (C. occidcnt~iiis Freeman. C. orae Freeman, and C. hicrltris Freeman). The three western species have the same mtDNA marker pattern in most individuals and, although ecologically differentiated. their populations may act~ally be conspecific. At one locality in AIaqka, pheromone traps baited with lures for C. ,fitm~ferana attract moths with C. jfionifcrana nitDNA, and lures for C. orac attract moths with mtDNA that is characteristic of tlie western asscmhluge. This demonstrates geographic overlap of genetically distinct species in Alaska. The same two separate mtDNA lineages co-occur at two localities in Alberta, but pheromone attraction is unknown. In British Columbia, populations identified as C. hietlnis and C. orr~itlentalis contain a few individuals with divergent mtDNA genotypes, the significance of which remains unclear. Amplified mtDNA thus provides a convenient, reliable marker for surveying genetic variation within species and for studying interactions among species of the C. fumiferana group. Sperling, F.A.H., et D.A. Hickey. 1995. L'ADN mitochondria1 amplifik, un outil d'identification des espkces de Choristoneura (Lepidoptera: Tortricidae) parasites des coniferes. The Canadian Entomologist 127: 277-288.
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Genomic organization and expression of a trypsin gene from the spruce budworm, Choristoneura fumiferana
Insect biochemistry and molecular biology, 1995Co-Authors: Shaojiu Wang, Felix Young, Donal A. HickeyAbstract:A 7 kb (kilobase) genomic fragment containing a trypsin gene from the spruce budworm Choristoneura fumiferana was isolated and sequenced. The coding sequence is interrupted by two introns; these occur at the same positions as the first two introns of mammalian trypsin genes. The three exons encode 256 amino acids. The deduced protein sequence displays all of the structural features that characterize trypsin enzymes in other eukaryotic organisms. Genomic Southern hybridization showed that there is only one copy of the trypsin gene in the Choristoneura genome. This gene is expressed in the insect midgut, where the pH is extremely high. The complete lack of Lysine residues may be an adaptation to the high pH conditions. Extensive sequencing of the flanking regions did not reveal the presence of any linked trypsin-encoding genes. Instead, several short repetitive sequences and a sequence homologous to a Drosophila reverse transcriptase gene was identified in this genomic region.
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Mitochondrial DNA sequence variation in the spruce budworm species complex (Choristoneura: Lepidoptera).
Molecular biology and evolution, 1994Co-Authors: Felix A. H. Sperling, Donal A. HickeyAbstract:A combination of polymerase-chain-reaction amplification and automated DNA sequencing was used to survey variation in a species complex of pest insects, the spruce budworms (Choristoneura fumiferana species group), and an outgroup species, C. rosaceana. We sequenced an mtDNA region of 1,573 bp that extends from the middle of cytochrome oxidase subunit I (COI) through tRNA leucine (UUR) to the end of cytochrome oxidase subunit II. In addition, we examined levels of intraspecific variation within a 470-bp region of the COI gene. Choristoneura fumiferana clearly represented the oldest lineage within its species group, with 2.7%-2.9% sequence divergence from the other species. In contrast, the four remaining species (C. pinus, C. biennis, C. occidentalis, and C. orae) had closely related or identical mtDNA, with < 1% divergence among most of their haplotypes. Despite its older lineage and widespread geographic distribution, C. fumiferana showed significantly lower intraspecific genetic diversity than did C. occidentalis. Choristoneura orae shared haplotypes with C. occidentalis and C. biennis, and species-level separation of these three species was not supported. Two divergent, uncommon haplotypes were also found in C. occidentalis and C. biennis. The divergent haplotype in C. biennis had an unusually high number of inferred amino acid replacements, suggesting selective differences between mitochondrial DNA haplotypes. Transition:transversion ratios in Choristoneura paralleled those found in Drosophila; transition:transversion ratios were highest in closely related sequences but decreased with increasing sequence divergence. Nucleotide composition showed an A+T bias that was near the high end of the range known for insects. This work illustrates the potential utility of direct DNA sequencing in assessing population structures, species limits, and phylogenetic relationships among organisms that have not previously been subjected to DNA analysis.
Bryan M. T. Brunet - One of the best experts on this subject based on the ideXlab platform.
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Genus delimitation, biogeography and diversification of Choristoneura Lederer (Lepidoptera: Tortricidae) based on molecular evidence
Systematic Entomology, 2018Co-Authors: Giovanny Fagua, Fabien L. Condamine, Jason J. Dombroskie, Bong-kyu Byun, Jurate De Prins, Thomas J. Simonsen, Marcos Báez, Bryan M. T. Brunet, Felix A. H. SperlingAbstract:Widely known for pest species that include major modulators of temperate forests, the genus Choristoneura is part of the species-rich tribe Archipini of leafroller moths (Tortricidae). Delimitation of the genus has remained unresolved because no phylogeny has included species endemic to Africa and studies have often omitted the type species of the genus. Further taxonomic confusion has been generated by the transfer of Archips occidentalis (Walsingham) to Choristoneura, creating a homonym with Choristoneura occidentalis Freeman, an important defoliator of North American forests. To define the limits of the genus, we reconstructed a phylogeny using DNA sequences for mitochondrial cytochrome oxidase subunit I and nuclear ribosomal 28S genes. Our ingroup included 23 Choristoneura species-level taxa, complemented by a large sample of outgroups comprising 82 species of Archipini and other Tortricidae. We generated a time-calibrated tree using fossil and secondary calibrations and we inferred biogeographic and diversification processes in Choristoneura. Our analysis recovered the genus as polyphyletic, with Archips occidentalis, Choristoneura simonyi and Choristoneura evanidana excluded from the main clade. Based on the recovered phylogenies and a redefinition, we restrict Choristoneura primarily to species with a northern hemisphere distribution. Our analysis supports A. occidentalis as the sister group of Cacoecimorpha pronubana, C. simonyi as the sister of ‘Xenotemna’ pallorana, and C. evanidana as the sister of Archips purpurana. A new combination is proposed: Archips evanidana comb.n.; the availability of ‘Xenotemna’ as a valid name is discussed and A. occidentalis is considered as an orphaned name within the Archipini. We found support for a Holarctic origin of Choristoneura about 23 Ma, followed by early divergence in the Palearctic region. The main divergence occurred at 16Ma, with one clade in the Nearctic and another in the Palearctic. Subsequent cladogenetic events were synchronous and related to herbivorous specialization, with each clade divided into coniferophagous and polyphagous lineages. Their specialization as conifer feeders temporally matched the expansion of boreal forest during the Miocene.
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Convergent herbivory on conifers by Choristoneura moths after boreal forest formation.
Molecular phylogenetics and evolution, 2018Co-Authors: Giovanny Fagua, Fabien L. Condamine, Bryan M. T. Brunet, Anne-laure Clamens, Jérôme Laroche, Roger C. Levesque, Michel Cusson, Felix A. H. SperlingAbstract:Abstract Mitogenomes are useful markers for phylogenetic studies across a range of taxonomic levels. Here, we focus on mitogenome variation across the tortricid moth genus Choristoneura and particularly the spruce budworm (Choristoneura fumiferana) species complex, a notorious pest group of North American conifer forests. Phylogenetic relationships of Tortricidae, representing two subfamilies, four tribes and nine genera, were analyzed using 21 mitogenomes. These included six newly-sequenced mitogenomes for species in the spruce budworm complex plus three additional Choristoneura species and 12 previously published mitogenomes from other tortricids and one from the Cossidae. We evaluated the phylogenetic informativeness of the mitogenomes and reconstructed a time-calibrated tree with fossil and secondary calibrations. We found that tortricid mitogenomes had conserved protein and ribosomal regions, and analysis of all protein-coding plus ribosomal genes together provided an efficient marker at any taxonomic rank. The time-calibrated phylogeny showed evolutionary convergence of conifer feeding within Choristoneura, with two independent lineages, the Nearctic spruce budworm complex and the Palearctic species Choristoneura murinana, both shifting onto conifers about 11 million years ago from angiosperms. These two host-plant shifts both occurred after the formation of boreal forest in the late Miocene. Haplotype diversification within the spruce budworm complex occurred in the last 4 million years, and is probably linked to the initial cooling cycles of the Northern Hemisphere in the Pliocene.
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Identification and ecological characterisation of Choristoneura occidentalis (Lepidoptera: Tortricidae) populations in southwestern Alberta, Canada
Canadian Entomologist, 2013Co-Authors: Bryan M. T. Brunet, Anina E. Hundsdoerfer, Felix A. H. SperlingAbstract:The western spruce budworm, Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae), is an important pest of western North American coniferous forests, where its principal larval host is Rocky Mountain Douglas-fir, Pseudotsuga menziesii subspecies glauca (Beissner) Murray (Pinaceae). In southwestern Alberta, Canada, populations were recently discovered feeding on an unconventional host, an Engelmann spruce, Picea engelmannii Parry ex. Engelmann 3white spruce, Picea glauca (Moench) Voss hybrid (Pinaceae), in a transition zone between the two major forest types characterised by these conifer species. We use molecular evidence to verify the species identity of outbreaking Choristoneura populations collected from Douglas-fir and hybrid spruces in southwestern Alberta in 2009, and characterise the larval and male moth phenology. Both mito- chondrial and microsatellite markers confirmed these populations as C. occidentalis, but admixture with Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) was detected in some individuals. Few differences associated with separate host trees were evident in the phenology of larvae and the flight period of male moths. Resume´—La tordeuse occidentale de l'epinette, Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae) est un ravageur important des forets de coniferes de l'Ouest de l'Amerique du Nord, ou` son hote larvaire principal est le sapin bleu de Douglas, Pseudotsuga menziesii sous-especeglauca (Beissner) Murray (Pinaceae). Dans le sud-ouest de l'Alberta, Canada, des populations ont recemment eteobservees en train de se nourrir sur un hote inusite´, un hybride de l'epinette d'Engelmann, Picea engelmannii Parry ex. Engelmann, x epinette blanche, Picea glauca (Moench) Voss (Pinaceae), dans une zone de transition entre les deux types majeurs de foret caracterises par ces especes de coniferes. Des donnees moleculaires nous ont servi a erifier l'identitedes especes emiques de Choristoneura recoltees sur les sapins de Douglas et les epinettes hybrides dans le sud-ouest de l'Alberta en 2009 et ad ecrire la phenologie des larves et des papillons adultes males. Tant les marqueurs mitochondriaux que microsatellites confirment que ces populations sont des C. occidentalis, mais un melange avec Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) a eted ecelechez certains individus. Il y a peu de differences dans la phenologie des larves et la periode de vol des adultes en fonction des differents arbres-hotes.
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Identification and ecological characterisation of Choristoneura occidentalis (Lepidoptera: Tortricidae) populations in southwestern Alberta, Canada
The Canadian Entomologist, 2013Co-Authors: Bryan M. T. Brunet, Anina E. Hundsdoerfer, Felix A. H. SperlingAbstract:AbstractThe western spruce budworm, Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae), is an important pest of western North American coniferous forests, where its principal larval host is Rocky Mountain Douglas-fir, Pseudotsuga menziesii subspecies glauca (Beissner) Murray (Pinaceae). In southwestern Alberta, Canada, populations were recently discovered feeding on an unconventional host, an Engelmann spruce, Picea engelmannii Parry ex. Engelmann × white spruce, Picea glauca (Moench) Voss hybrid (Pinaceae), in a transition zone between the two major forest types characterised by these conifer species. We use molecular evidence to verify the species identity of outbreaking Choristoneura populations collected from Douglas-fir and hybrid spruces in southwestern Alberta in 2009, and characterise the larval and male moth phenology. Both mitochondrial and microsatellite markers confirmed these populations as C. occidentalis, but admixture with Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) was detected in some individuals. Few differences associated with separate host trees were evident in the phenology of larvae and the flight period of male moths.
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Characterization of EST-based SSR loci in the spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae)
Conservation Genetics Resources, 2013Co-Authors: Bryan M. T. Brunet, D. Doucet, Brian R. Sturtevant, Felix A. H. SperlingAbstract:After identifying 114 microsatellite loci from Choristoneura fumiferana expressed sequence tags, 87 loci were assayed in a panel of 11 wild-caught individuals, giving 29 polymorphic loci. Further analysis of 20 of these loci on 31 individuals collected from a single population in northern Minnesota identified 14 in Hardy-Weinberg equilibrium.
Arthur Retnakaran - One of the best experts on this subject based on the ideXlab platform.
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Effect of RH-5992 on adult development in the spruce budworm, Choristoneura fumiferana.
Insect biochemistry and molecular biology, 2002Co-Authors: M. Sundaram, Peter J Krell, M Primavera, W.l. Tomkins, Subba Reddy Palli, Guy Smagghe, Isaac Ishaaya, Qili Feng, Arthur RetnakaranAbstract:The effect of RH-5992 (tebufenozide), a non-steroidal ecdysone agonist, on adult development of the spruce budworm, Choristoneura fumiferana, was investigated by administering the compound intrahemocoelically to pupae on days 1-6 after pupal ecdysis. At concentrations of 200ng/pupa there was significant mortality but at doses of 50-100ng/pupa, the emerging adults displayed wing deformities which reduced their ability to mate and oviposit. Light microscopy of the pupal wings revealed that there was degeneration of the epithelial cells, reduction in the number of veins, precocious cuticle formation and inhibition of growth of normal wing scales. Injection of RH-5992 into pupae resulted in a dose dependent induction of mRNA for ecdysone-induced transcription factor, Choristoneura hormone receptor 3 (CHR3). These results suggest that the pupae respond to RH-5992 in a manner similar to larvae. However, the effects are not expressed overtly and are camouflaged by the pharmacological effects.
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FEEDING BEHAVIOUR OF THE FIRST-INSTAR Choristoneura FUMIFERANA AND Choristoneura PINUS PINUS (LEPIDOPTERA: TORTRICIDAE)
The Canadian Entomologist, 1999Co-Authors: Arthur Retnakaran, M Primavera, W.l. Tomkins, Subba Reddy PalliAbstract:We have discovered that, contrary to the long-held belief, 1st-instar spruce budworm, Choristoneura fumiferana Clemens, do feed. They display red alimentary tracts if they are provided with diet containing the red dye amaranth. They graze on the surface of balsam fir needles sprayed with rhodamine and ingest the fluorescent material, which can be detected in the frass pellets deposited inside the hibernacula. When emerging 1st instars were allowed to crawl on the inside surface of a glass tube coated with the polyhedral inclusion bodies of a recombinant C . fumiferana virus containing the gene for the green fluorescent protein, the larvae showed the characteristic green fluorescence, indicating that not only had they ingested the occlusion bodies but also the virus had replicated and infected different tissues. Similar results were obtained with the jack pine budworm, Choristoneura pinus pinus Freeman, which has an identical life history. The advantages of early-instar intervention to minimize defoliation by using control agents such as the ecdysteroid agonist, tebufenozide (RH-5992, Mimic ® formulation), are discussed.
Kees Van Frankenhuyzen - One of the best experts on this subject based on the ideXlab platform.
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Molecular Data and Phylogeny of Nosema Infecting Lepidopteran Forest Defoliators in the Genera Choristoneura and Malacosoma
The Journal of eukaryotic microbiology, 2008Co-Authors: George Kyei-poku, Debbie Gauthier, Kees Van FrankenhuyzenAbstract:Nosema isolates from five lepidopteran forest defoliators, Nosema fumiferanae from spruce budworm, Choristoneura fumiferana; a Nosema sp. from jack pine budworm, Choristoneura pinus pinus and western spruce budworm, Choristoneura occidentalis (Nosema sp. CPP and Nosema sp. CO, respectively); Nosema thomsoni from large aspen tortrix, Choristoneura conflictana; and Nosema disstriae, from the forest tent caterpillar, Malacosoma disstria were compared based on their small subunit (SSU) ribosomal RNA (rRNA) gene sequences. Four of the species sequenced, N. fumiferanae, Nosema sp. CPP, Nosema sp. CO, and N. disstriae have a high SSU rDNA sequence identity (0.6%-1.5%) and are members of the "true Nosema" clade. They all showed the reverse arrangement of the (large subunit [LSU]-internal transcribed spacer [ITS]-SSU) of the rRNA gene. The fifth species, N. thomsoni has the usual (SSU-ITS-LSU) arrangement and is not a member of this clade showing only an 82% sequence similarity. We speculate, therefore, that a genetic reversal may have occurred in the common ancestor to the "true Nosema" clade. Although, the mechanism for rearrangement of the rRNA gene subunits is not known we provide a possible explanation for the localization. N. fumiferanae, Nosema sp. CPP, and Nosema sp. CO clustered together on the inferred phylogenetic tree. The high sequence similarities, the reverse arrangement in the rRNA gene subunits, and the phylogenetic clustering suggest that these three species are closely related but separate species.
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occurrence of cystosporogenes sp protozoa microsporidia in a multi species insect production facility and its elimination from a colony of the eastern spruce budworm Choristoneura fumiferana clem lepidoptera tortricidae
Journal of Invertebrate Pathology, 2004Co-Authors: Kees Van Frankenhuyzen, Peter M. Ebling, Tim R. Ladd, Debbie Gauthier, Bob Mccron, Charles R VossbrinckAbstract:We have isolated a microsporidium from a laboratory colony of the eastern spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae). Light and electron microscopic investigations showed that gross pathology and ultrastructure of our isolate are similar to those described for Cystosporogenes legeri from the European grape vine moth, Lobesia botrana. Comparative phylogenetic analysis of the small subunit rDNA using maximum likelihood, maximum parsimony, and neighbour joining distance methods revealed perfect homology with the C. legeri sequence. The microsporidian was infectious to other Choristoneura species, as well as Malacosoma disstria, Lymantria dispar, and Lambdina fiscellaria. Incubation of infected egg masses at 41 °C for 20 min followed by 30 min in 33% formaldehyde did not reduce disease incidence in larval offspring. Exposure of one or two generations to fumagillin at 6000 ppm or higher eliminated infection in adult moths, but also reduced colony fitness. A clean colony was established by conducting individual matings and selecting disease-free offspring.