A5090575825- Forest Insect Ecology and Management
- Insect-Plant Interactions and Control
- Insect and Pesticide Research
- Fire effects on ecosystems
- Ecology and Vegetation Dynamics Studies
- Plant and animal studies
- Forest Ecology and Biodiversity Studies
- Plant Parasitism and Resistance
- Hymenoptera taxonomy and phylogeny
- Parasite Biology and Host Interactions
- Nematode management and characterization studies
- Insect and Arachnid Ecology and Behavior
- Bird parasitology and diseases
- Insect Pheromone Research and Control
- Animal Ecology and Behavior Studies
- Entomopathogenic Microorganisms in Pest Control
- Insect Resistance and Genetics
- Vector-borne infectious diseases
- Forest ecology and management
- Entomological Studies and Ecology
- Avian ecology and behavior
- Species Distribution and Climate Change
- Hemiptera Insect Studies
- Marine Biology and Ecology Research
- Insect behavior and control techniques
Natural Resources Canada
2013-2022
Canadian Forest Service
2013-2022
University of New Brunswick
2007-2022
Government of New Brunswick
1996
Vineland Research and Innovation Centre
1982
Memorial University of Newfoundland
1978
Patterns in food-web structure have frequently been examined static food webs, but few studies attempted to delineate patterns that materialize webs under nonequilibrium conditions. Here, using one of nature's classical systems as the database, we test major assumptions recent advances theory. We show a complex web interactions between insect herbivores and their natural enemies displays significant architectural flexibility over large fluctuation abundance herbivore, spruce budworm...
Wolbachia is a genus of bacterial endosymbionts that impacts the breeding systems their hosts. can confuse patterns mitochondrial variation, including DNA barcodes, because it influences pathways through which mitochondria are inherited. We examined extent to these detected in routine barcoding, assessed impact upon insect sequence divergence and identification accuracy, considered variation present COI. Using both standard PCR assays (Wolbachia surface coding protein – wsp), COI fragments...
Abstract Microgastrine wasps are among the most species‐rich and numerous parasitoids of caterpillars (Lepidoptera). They often host‐specific thus extensively used in biological control efforts figure prominently trophic webs. However, their extraordinary diversity coupled with occurrence many cryptic species produces a significant taxonomic impediment. We present release results 8 years (2004–2011) DNA barcoding microgastrine wasps. Currently they best represented group parasitoid...
The efficient and effective monitoring of individuals populations is critically dependent on correct species identification. While this point may seem obvious, identifying the majority more than 100 natural enemies involved in spruce budworm (Choristoneura fumiferana – SBW) food web remains a non-trivial endeavor. Insect parasitoids play major role processes governing population dynamics SBW throughout eastern North America. However, these are at leading edge taxonomic impediment integrating...
Laboratory experiments were performed to determine the functional response prey density of various instars two species predacious phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, examine effects predator age nutritional history on their responses. The showed that requirements predators, time they are exposed in relation life-span, increasing age, differences history, can have important predatory behaviour response. Prolonged exposure one cause lags predation rates when is...
Two hundred and seventy alcids representing six species from Newfoundland, Canada, were examined for Mallophaga. A total of 12 belonging to three genera (Saemundssonia, Cummingsiella, Austromenopon) recovered. Each host the parasites recovered it are discussed separately. Details prevalence intensity parasitism given, as seasonal annual data. Differences between burdens adults chicks recorded infestation is related ecology hosts.
Abstract We conducted a 14‐yr intensive study of spruce budworm ( Choristoneura fumiferana (Clem.)) survivorship at three plots in largely balsam fir Abies balsamea (L.) Mill.) stands New Brunswick, Canada, to elucidate certain key mechanisms underlying outbreak cycles. The covered peak‐to‐declining phase (from 1981 and 1994) the cycle that had started early 1960s. Frequent sampling was carried out each plot‐year construct practically continuous curve, annual variation population density...
Defoliation by spruce budworm (Choristoneura fumiferana Clem.) on balsam fir (Abies balsamea (L.) Mill.) is more severe in than mixed fir-hardwood stands. Previous studies assumed that defoliation stands was reduced proportion to percent hardwood regardless of outbreak severity. We tested the influence stand composition during first 5 years a near Amqui, Quebec, sampling 27 plots selected represent three basal area classes (0%–25%, 40%–65%, and 75%–95%). Balsam significantly lower (p <...
Experiments on the responses of two species predacious phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, to their own density revealed that, with exception adult female P. persimilis, individual predation rates all instars both increased as predator prey densities were within certain fixed ratios. "Interference" between was suggested a possible reason for this result, confirmed by application Hassell Varley's model data from an experiment where various densities....
Summary Ecosystem alterations can affect the abundance, distribution and diversity of plants animals, thus potentially change relative strength bottom‐up (the plant resource) top‐down (natural enemies) trophic forces acting on herbivore populations. The hypothesis that forest ecosystem associated with precommercial thinning have contributed to increased severity outbreaks Neodiprion abietis (Harris), a sawfly defoliator, through reduction N. larvae, was tested using exclusion techniques....
Summary 1. Oviposition behaviour and host size − fitness relationships of a gregarious, idiobiont ectoparasitoid, Elachertus cacoeciae (Howard) (Hymenoptera: Eulophidae), were studied by implanting one fourth‐, fifth‐, sixth‐instar spruce budworm Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) larva per tree in stand where the density wild C. population was low. 2. Development time E. larvae quickest on fifth‐instar larvae, which preferred hosts for oviposition. 3. Brood sex...
The numerical responses of two species phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, were studied in the laboratory. Developmental times survival rates examined immature instars oviposition adult females. Prey requirements for development, survival, lower with P. than A. degenerans due to nature their respective feeding searching behaviour. fecundity increased linearly increasing numbers prey killed, whereas that curvilinearly. Experiments on effects history females...
Abstract A 5-yr field study was carried out to assess intratree variations in the distribution, abundance, and mortality of immature spruce budworm (Choristoneura fumiferana Clemens) (Lepidoptera: Tortricidae) from peak collapse an outbreak. In most years, highest density overwintering second-instar (L2) larvae (per square meter foliage) located lower crown, whereas all subsequent stages (third- sixth-instar larvae, pupae, eggs) were at relatively higher densities upper crown. contrast,...
Abstract An illustrated key is given to 28 genera, representing 10 families of at least 50 chalcidoid parasitoids and hyperparasitoids recorded from Choristoneura species (Tortricidae), or their primary parasitoids, in America north Mexico. We include reared throughout a 12-year study the associated with spruce budworm, fumiferana (Clemens), New Brunswick, Canada, as well those listed various catalogs. Notes are provided for all species, whether not they literature. Nine doubtfully...
Abstract Two stands of intensively managed balsam fir [ Abies balsamea (L.) Mill. (Pinaceae)] in western Newfoundland, located within an area infested by the sawfly, Neodiprion abietis (Harr.) (Hymenoptera: Diprionidae) complex, were selected to study growth loss and recovery following severe defoliation sawfly early 1990s. Four years after start outbreak, volume increments reduced 78–81%. The decreased increment coincided well with outbreak decline. rates slow due absence bud destruction,...
Male Lepidoptera often possess specialized scales, called hair pencils that emit volatiles are critical to mating success. Spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), males will display females before attempting copulation. The importance of on these is, however, not clear. We compared the proportion successful copulations in unmanipulated pairs where had their either removed or chemically washed, and were antennectomized. Mean proportions matings...
Longidorus diadecturus n. sp., a virus vector found in peach orchards southwestern Ontario, is described and illustrated. The most distinguishing feature of the species posterior position stylet guiding ring (50–64 μm to head apex). It differs from closely related with by shape length corpal mucro (sagittate, 1–2 μm), odontophore (55–66 expanded, set-off head, anteriorly located vulva (44–48%). body lengths tail shapes sizes are also diagnostic for larval stages.
Both Phytoseiulus persimilis and Amblyseius degenerans exhibited area-restricted searching after prey capture(s) regardless of the density distribution experienced. A reduction in speed an increase absolute magnitude turns following contributed to under all conditions with P. persimilis, whereas A. degenerans, was due factors other than a consistent change these parameters conditions. modified its overall behaviour greater extent at low high densities clumped uniform distributions, showed...
Abstract 1 Nosema fumiferanae infections in populations of both sexes spruce budworm Choristoneura fumiferana moths, collected live above the forest canopy (canopy moths), within tree crown (crown moths) and drop trays (dead were examined over a 5‐year period New Brunswick, Canada. 2 The incidence infection moderate–heavy moths increased concomitantly with moth eclosion, indicating that N. retards larval/pupal development, infected particularly those having higher disease loads, emerging...
The effect of cumulative defoliation caused by spruce budworm (Choristoneura fumiferana [Clem.]) from 1981 to 1987 on tree growth was assessed in a 35-year-old balsam fir (Abies balsamea [L.] Mill.) stand. After six years moderate severe defoliation, specific volume increment reduced an average 11, 55, 83, 70, and 83% for trees with visual ratings, 1987, 1–25%, 26–50%, 51–75%, 76–90%, 91–100%, respectively. Following mean ranged 0.02 cm 3 −2 year −1 >90% 0.16 <25% defoliation. Specific...
The prevalence, intensity and transmission of Nosema fumiferanae (Thomson) (Microsporidae) infections potential impacts on the survival field populations spruce budworm Choristoneura fumiferana (Clem.) were examined in three plots New Brunswick, Canada, from 1983 to 1992. highest prevalence N. infection post‐hibernation second‐instar larvae occurred plot where female pupae was previous generation, suggesting higher rates vertical transmission. There little change between second sixth instars...
Summary The stage‐specific responses of eruptive populations to ecosystem alterations have received little attention, despite the relevance issue for conservation biology and pest management. This study examined hypothesis that forest thinning treatments affect outbreak cycles Neodiprion abietis , a sawfly defoliator. densities eggs, early instar larvae, late‐instar cocoons adults N. were monitored during an in thinned adjacent untreated stand at each three sites western Newfoundland,...
A laboratory study was conducted to determine the effects of prey distribution in an homogeneous area on searching success and functional response two species phytoseiid mites, Phytoseiulus persimilis Amblyseius degenerans. The results indicated that spatial affected P. but not A. More were killed by former predator when clustered, followed random uniform distributions. In contrast degenerans, degree aggregation at a given density also number persimilis. With both predators, depletion...