The Canadian registration in 2007 of Disrupt SBW Micro-Flakes®, a pheromone-based product for control of spruce budworm, Choristoneura fumiferana (Clemens), paved the way for large-scale trials to test the practicality of mating disruption as a commercial pest management strategy. We review results from field and laboratory experiments on pheromone-based mating disruption of spruce budworm conducted from 1974 to 2008. Application of pheromone from the ground or the air consistently reduced the orientation of males toward pheromone sources. Mating disruption also reduced the mating success of caged or tethered females in 15 of 16 field studies where this parameter was recorded, but had only a limited effect on the mating success of feral females. No consistent difference in the density of egg masses in control and treated plots was observed, which has often been attributed to immigration of gravid females into pheromone-treated plots. Laboratory studies suggest that false-trail following is the predominant mechanism underlying mating disruption in spruce budworm. The enhanced mating success of females with increasing population density suggests that mating disruption should target low-density emergent populations during the initial phase of an outbreak. Constraints that may limit the potential of mating disruption as a management tool include (1) difficulties associated with obtaining accurate sampling estimates at low population density to forecast the onset of outbreaks, (2) potential behavioral adaptations by which females enhance their mating success when the atmosphere is treated with pheromone, and (3) long-range dispersal of females by flight.

Spruce budworm, Choristoneurafumiferana (Clemens) (Lepidoptera: Tortricidae), larvae can cause extensive defoliation in balsam fir (Abies balsamea [Linnaeus] Miller) and exhibit high temporal and spatial variability in individual behaviour. We gathered field data to determine the influence of daily and hourly variation in abiotic conditions on daytime activity patterns of late-instar budworm larvae on balsam fir. In both years of our study, less than 10% of larvae were observed feeding during the daytime. Most larvae observed were either resting, spinning silk, or roaming, although the proportion of individuals engaged in each activity varied between years, with more larvae in the first year roaming (48%) and in the second year either resting (38%) or spinning silk (42%). Daily and hourly variation in abiotic conditions had a limited influence on activity patterns. Our results indicate that in nature, mid- to late-instar budworm larvae maintain fairly consistent activity patterns across a wide range of abiotic conditions. We suggest that site-specific conditions such as variation in host-plant quality and/or budworm population density may be more important than weather in determining the relative frequencies of different larval activities in space and time.

The population stability of Baizongia pistaciae (Linnaeus) (Hemiptera: Aphididae) on its primary host, the tree Pistacia palaestina Boissier (Anachardiaceae), was investigated using 17–20 years of data from a study of gall abundance on individual trees in Israel. Abundance varied by at least an order of magnitude among adjacent trees, among locations, and among years. Stability was quantified for the alternate-year cohorts as population variability (PV) and persistence, at three spatial scales. PV (a proportion between 0 and 1) was similar between cohorts and declined with population scale – subpopulation (a tree): 0.676 ± 0.092 (±1 SD, n = 40); population: 0.581 ± 0.098 (±1 SD, n = 6); region: 0.424 (0.345 and 0.503, n = 2). Persistence (proportion of years that galls were present) was usually near 0.9, but 0.1 for some subpopulations, and 1.0 at the population and regional scales. Although protected within large galls on long-lived trees, the PV of B. pistaciae was similar to that of native, free-living aphid species on more ephemeral herbaceous hosts, but lower than for introduced aphid species. Persistence of B. pistaciae decreased as abundance decreased but not as PV increased. PV did not increase with the length of the study period; and declined with increasing population scale, because abundance was not synchronised among subpopulations or populations. PV was similar among populations, suggesting this parameter is characteristic of the species, although positive correlations between cohorts on a tree showed that PV was affected by the site-specific tree–grass habitats in which this species lives.

Garry oak, Quercus garryana Douglas ex Hooker (Fagaceae), is part of a unique ecosystem in British Columbia, Canada, which is rich in rare and endangered plant species. Garry oak recruitment is critical to the existence of this ecosystem, therefore, the effect of Curculio occidentis (Casey) (filbert weevil; Coleoptera: Curculionidae) and Cydia latiferreana (Walsingham) (filbertworm; Lepidoptera: Tortricidae) on acorn germination is of great interest. Together these two insects infested 80.7%, 75.1%, and 51.3% of acorns collected in 1996, 1997 (low crop years), and 1998 (high crop year), respectively. Filbertworm infestation did not vary with crown level. Filbert weevil infestation did not vary with crown level during poor crop years, but significantly more filbert weevil-infested acorns were found in the lower than the middle and upper portions of the trees during the high crop year. Severely damaged acorns did not germinate, and acorns with light to moderate feeding damage had lower germination success than undamaged acorns, but growth of germinated seedlings in the light to moderate damage category was unaffected. This study showed, for the first time, that these two insect species infested a large proportion of Garry oak acorns on the tree in British Columbia, and that light to moderate damage of the acorn has relatively low impact on seedling growth.

In this study, we assessed the relationship between the size of bolts cut from pin oak trees, Quercus palustris Münchhausen (Fagaceae), and eastern white pines, Pinus strobus Linnaeus (Pinaceae), and the number and body size of cerambycid beetles (Coleoptera: Cerambycidae) that develop within them. From oak bolts emerged adult Graphisurus fasciatus (De Geer) (98% of beetles) and Xylotrechus colonus (Fabricius), while pine bolts produced Monochamus carolinensis (Olivier) (95%) and Astylopsis sexguttata (Say). The number of G. fasciatus was positively correlated with the diameter of the oak bolts, while the greatest number of M. carolinensis emerged from pine bolts of intermediate diameter. Body size of both species was positively correlated with bolt diameter. Rates of parasitism were very low, only 0.9% for oaks, and averaging 5.3 ± 8.6% across pine bolts. Oak bolts yielded the braconid wasps (Hymenoptera: Braconidae) Wroughtonia ferruginea (Brues) and a species in the genus Atanycolus Förster (similar to Atanycoluscharus (Riley)), and an ichneumonid (Hymenoptera: Ichneumonidae) in the genus Demopheles Förster. Pine bolts produced a braconid in the genus Digonogastra Viereck, and the tachinid fly (Diptera: Tachinidae) Billaea monohammi (Townsend).

During 1994–2008, 58 adult and 195 juvenile eastern cottontail rabbits (Sylvilagus floridanus (Allen)), one adult and 23 juvenile snowshoe hares (Lepus americanus Erxleben), and eight adult white-tailed jackrabbits (Lepus townsendii Bachman) (Mammalia: Leporidae) were examined for ectoparasites. The most abundant ectoparasite on cottontails was the sucking louse, Haemodipsus setoni Ewing (Phthiraptera; Polyplacidae), recorded from this host for the first time. Infestations in adult and juvenile cottontails were highly aggregated, k = 0.136 and 0.153, respectively. Prevalence of infestation in adult cottontails was 70.6%, with a mean intensity of 5614.1 (range: 1–166 249); 10 adults had more than 1000 lice. In juvenile cottontails, prevalence was 34.8% and mean intensity was 6.2 (range: 1–87). On adult cottontails, 73.4% of the total lice were nymphs, while on juvenile cottontails only 11.6% were nymphs. It appears that dispersal from parents to offspring is overwhelmingly achieved by adult lice. Seventeen adult cottontails were infested with the tick, Haemaphysalis leporispalustris (Packard) (Acari: Ixodidae). No fleas specific to rabbits were collected but small numbers of the rodent fleas Monopsyllus vison (Baker), Orchopeas caedens (Jordan), and Aetheca wagneri (Baker) (Siphonaptera: Ceratophyllidae) were recorded. Only one snowshoe hare was infested with H. setoni and three were infested with H. leporispalustris; no fleas were found on snowshoe hares. Two white-tailed jackrabbits were infested with H. leporispalustris; one carried Pulex irritans Linnaeus (Siphonaptera: Pulicidae), and none carried lice.

Food quality can influence the performance of immature insects and their interactions with pathogens, such as viruses. In manipulative field studies, virus-free caterpillars of the whitemarked tussock moth (WMTM) (Orgyia leucostigma (Smith)) had higher survival, more female-biased sex ratios, and were larger when feeding on white birch (Betula papyrifera Marshall) versus balsam fir (Abies balsamea (Linnaeus) Miller) or red spruce (Picea rubens Sargent). Subsequent laboratory studies with two nucleopolyhedroviruses, derived from WMTMs and Douglas-fir tussock moths, indicated that caterpillars fed high quality food (i.e., artificial diet) prior to infection had less mortality associated with virus infection than those feeding on lower quality foliage (i.e., birch). In field studies, caterpillars fed birch following infection had significantly lower mortality than those feeding on relatively lower quality foliage (i.e., balsam fir). We postulate that higher nutritional quality in artificial diet relative to birch (previrus-ingestion nutrition) and in birch relative to balsam fir foliage (postvirus-ingestion nutrition) has a positive effect on the ability of tussock moth caterpillars to resist or recover from viral infections, although the specific mechanisms responsible for observed resistance remain unclear.

Using immunostaining methodology, we traced the axonal projection of FMRFamide (Phe-Met-Arg-Phe-NH2)-like immunoreactive (LI) medial neurosecretory cells (MNCs) and lateral neurosecretory cells (LNCs) from the brain into the ventral nerve cord (VNC) and retrocerebral complex in Bombyx mori (L.) (Lepidoptera: Bombycidae). Of the seven pairs of FMRFamide-LI MNCs, one pair extended its axons from the brain pars intercerebralis into the VNC ipsilateral connective where they appeared to terminate. The axons of the remaining MNCs ran through decussation in the brain median region and contralateral nervi corporis cardiaci (NCC) I out of the brain, and eventually innervated the contralateral corpus cardiacum (CC). Axons from the single pair of FMRFamide-LI LNCs projected into the ipsilateral NCC II fused with NCC I without decussation in the brain, and finally terminated in the CC. These results suggest that transport of the FMRFamide-like neuropeptide from may be related to the modulation of functions such as gut contraction in MNCs terminating in the VNC, and regulation of production and/or secretion of specific hormones such as juvenile hormone in MNCs and LNCs terminating in the CC.

Host tree diameter is considered an important predictor of the population dynamics of the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), but the relationship between host tree diameter and beetle traits is unclear. The primary objective of this study was to determine how the quality of individual mountain pine beetles, measured as body size (pronotum width) and lipid content, varied with the diameter of lodgepole pine trees, Pinus contorta var. latifolia Engelmann (Pinaceae). Naturally attacked trees, ranging in diameter from 10 to 35 cm, were selected from stands near Prince George, British Columbia, Canada. Colonisation density and pupal density generally increased with tree diameter, but the number of pupal chambers per gallery start remained constant. Tree diameter positively affected beetle body size, which in turn was positively correlated with absolute lipid content in both sexes and relative lipid content in males. However, tree diameter did not directly predict absolute lipid content, and relative lipid content decreased with tree diameter in males. Larger beetles emerged earlier in the emergence period with relative lipid content remaining constant throughout emergence. All relationships had considerable unexplained variation. Thus, the use of tree diameter or emergence time as predictors of population dynamics of mountain pine beetles should be done with caution.

Managed and wild colonies of common eastern bumble bee (Bombus impatiens Cresson) (Hymenoptera: Apidae) are effective pollinators of wild blueberry (Vaccinium angustifolium Aiton) (Ericaceae) in Atlantic Canada. Because insecticides are used during bloom to manage insect pests, bumble bees may be at risk of exposure. We therefore assessed the susceptibility of B. impatiens to some insecticides used or projected for use in blueberry pest management. Workers were killed by topical applications of spinosad, spinetoram, deltamethrin, and phosmet, but not flubendiamide. Similarly, when ingested in honey solution, spinetoram and deltamethrin were toxic, whereas flubendiamide did not cause mortality up to double its recommended label rate. In another experiment, workers were fed one sublethal dose of contaminated honey solution and placed in microcolonies to assess impacts on feeding, life span, and reproduction. The highest concentration of deltamethrin (17 mg a.i./L) reduced feeding. Workers treated with deltamethrin had shortened life spans and produced fewer males. Flubendiamide (2000 mg a.i./L) and spinetoram (0.8 mg a.i./L) caused no sublethal effects. These results indicate that flubendiamide should be safe to apply to blueberries where B. impatiens is foraging, while some other insecticides we tested may be hazardous under different exposure scenarios.

Two parasitoids, identified as a species each of Aprostocetus Westwood (near Aprostocetusmarylandensis (Girault)) (Hymenoptera: Eulophidae) and Platygaster Latreille (Hymenoptera: Platygastridae), were discovered in cranberry shoots (Vaccinium macrocarpon Aiton (Ericaceae)) infested with cranberry tipworm, Dasineura oxycoccana (Johnson), on a farm in Pitt Meadows, British Columbia, Canada. Parasitoids emerged from ∼18% of collected shoots in 2009, when Aprostocetus sp. was more numerous, and in 2010, when Platygaster sp. predominated. In 2009, Aprostocetus sp. was the only parasitoid species present in May and June, and predominated until late August, when Playtgaster sp. became prevalent. In 2010, Platygaster sp. was more numerous throughout June and July; numbers of Aprostocetus sp. increased in late July and early August. The parasitoids were naturally present despite applications of the insecticide diazinon.

Ants (Hymenoptera: Formicidae) are ubiquitous and of considerable ecological interest, yet poorly studied in Canada. Given their natural history attributes and relatively low density and diversity in cool boreal forests, there is a need to evaluate the applicability of commonly used approaches to sampling and analysis. We examined the relative utility of two pitfall trap designs, mini-Winkler litter extractions, and colony versus forager sampling for ecological studies. First, we found that Laurent (conventional) and Nordlander (modified to exclude larger nontarget organisms) pitfall traps were equally efficacious for estimating total species richness. Second, pitfall trapping yielded marginally higher total species richness than mini-Winkler litter sampling, by the incidence-based estimator (Chao2). Third, two studies considering the relationship between captures of individual ants in pitfall traps and identified ant colonies argued for caution in how pitfall captures are interpreted. In the first study, Nordlander traps placed in a grid surrounding nests of Formica obscuripes Forel revealed unique and highly patchy captures of individuals, with no patterns relating to proximity to the nest. In the second study, abundance estimates to compare ant assemblage structure in a simple grassland ecosystem by pitfall trapping (relative) and area-based hand sampling (absolute) for colonies, revealed that relative sampling does not reflect the absolute ant assemblage structure. Our results support, equivocally, the use of pitfall traps (Nordlander) over mini-Winklers in the cool moist forests of west-central British Columbia, but individual specimen counts should not be used when analysing the data.