Sandy M Smith

University of Toronto | U of T

The psyllid Aphalara itadori Shinji (Hemiptera: Psyllidae) is a biocontrol agent against invasive knotweed species (Polygonaceae) in Europe and North America. Despite an extensive release program, successful establishment of the agent has never been confirmed. The slow establishment of A. itadori in its introduced range appears to be predominantly...

Temperature plays an important role in winter diapause of temperate insects. Its effects can cause problems for biological control programs, both for the establishment of insects in novel climates and for the mass rearing of insects in the laboratory. Hypena opulenta (Christoph) (Lepidoptera: Erebidae), a biological control agent for invasive swall...

Declining tree health status due to pollutant impacts and nutrient imbalance is widespread in urban forests; however, chemical fertilizer use is increasingly avoided to reduce eutrophication impacts. Biochar (pyrolyzed organic waste) has been advocated as an alternative soil amendment, but biochar alone generally reduces plant N availability. The c...

Effective management of the introduced invasive grass Phragmites australis (Cav.) Trin. ex Steud requires the ability to differentiate between the introduced and native subspecies found in North America. While genetic tools are useful for discriminating between the subspecies, morphological identification is a useful complementary approach that is...

Meta-analyses have become a valuable tool with which to synthesise effects across studies, but in ecology and evolution, they are often characterised by high heterogeneity, where effect sizes vary between studies. Much of this heterogeneity can be attributed to species-specific differences in responses to predictor variables. Here, we aimed to inco...

Urban forests are recognized worldwide as the most critical component of green infrastructure due to their capacity to provide various environmental goods and services. As cities continue to expand and their environmental problems intensify, there is a growing need for urban forests and green infrastructure to be better incorporated into strategic...

Although awareness of the influence of earthworms on soil seed banks in Canadian forests is growing, there have been few direct field measurements. We used a novel pairing of field-collected earthworms from a central Great Lakes forest in Ontario with a laboratory seed egestion assay to obtain a snapshot of the number of seeds passing through earth...

Boxwood (Buxus spp.) is one of the most commonly planted shrubs in urban landscapes across North America, and in Europe Buxus species comprise a significant portion of the forest understory. Cydalima perspectalis (colloquially known as the box tree moth) is a defoliator capable of causing mortality-inducing damage on boxwood in both natural and man...

Urban forests are recognized worldwide as the most critical component of green infrastructure due to their capacity to provide various environmental goods and services. As cities continue to expand and their environmental problems intensify, there is a growing need for urban forests and green infrastructure to be better incorporated into strategic...

The use of biochar with N-fixing species has been shown to enhance productivity of agricultural systems, both in N-fixing crops, as well as in mixed-species systems. Here we investigate the potential for the use of a granulated mixed conifer biochar and a sugar maple biochar in combination with N-fixing companion plants in an urban forestry context...

Introduced Phragmites (Phragmites australis ssp. australis) forms part of an invasion assemblage in North America that includes non-native insect herbivores and parasitoids, some of which are now found on both the introduced and native subspecies of Phragmites (P. australis ssp. americanus). This insect assemblage is key to understanding the impact...

Common obstacles for establishment of newly‐introduced biological control agents include climate and the activity of native antagonists. In temperate climates, these obstacles can disproportionately affect overwintering life‐stages because they are exposed to low winter temperatures, and may rely on passive defence from predators. We conducted a se...

The success of urban forestry depends on community support and engagement. How satisfied is the community with their urban trees is a useful way to understand these processes. However, public perception is complex and depends on a wide array of cognitive factors. How these factors relate and influence people’s level of satisfaction with urban trees...

Adaptation to artificial rearing conditions is a well-documented phenomenon in insects and has been shown to reduce the efficacy of biological control agents. The knotweed psyllid, Aphalara itadori Shinji (Hemiptera: Psyllidae), is a biological control agent for Fallopia japonica (Houtt.) Ronse Decr. (Caryophyllales: Polygonaceae) that has been rel...

Pale swallow-wort, Vincetoxicum rossicum (Kleopow) Barbar., is an invasive weed in the lower Great Lakes Basin of North America. We investigated the relationship between V. rossicum productivity and several environmental variables across 54 established V. rossicum populations in southern Ontario. Variables included climate measurements, soil charac...

Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provid...

Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provid...

Urban forests, integral to a city’s critical infrastructure, are traditionally under the mandate of local governments, yet in reality, the decision-making for their conservation is influenced by a myriad of factors operating at the neighbourhood level. In some neighbourhoods, decisions are heavily influenced by formal Resident Associations (RAs). U...

The egg parasitoid Trichogramma spp. (Hymenoptera: Trichogrammatidae) is a widely used biocontrol agent against lepidopteran pests. Historically, Trichogramma were deployed either by plane or by using cardboard cards on which parasitized eggs are glued and manually installed at sites. Plane deployment is costly and card installation is time consumi...

1. Pre‐release testing for biological control agents is focused primarily on assessment of host‐range specificity and safety of potential agents. Agent impact is considered pre‐release; however, the ultimate assessment of an agent must occur following release in the field under the target population levels and conditions of the invaded ecosystems....

The knotweed psyllid, Aphalara itadori , is a biological control agent for invasive knotweed species in North America and Europe. Initial releases were conducted in Canada in 2014 but establishment has been slow, seemingly as a result of low nymphal survival. We conducted two field experiments in Ontario, Canada, to explore the effects of native pr...

Many insects exhibit a short-day diapause response, whereby diapause is induced when daylength falls below a critical threshold. This response is an adaptation to ensure synchrony between periods of insect activity, and the availability of resources, but it can cause problems when organisms are moved to new locations, where early or late-induced di...

Spruce budworm (Choristoneura fumiferana (Clemens)) defoliation has been shown to increase the likelihood of large forest fires in central Canada. However, the time frame of heightened risk based on the duration of spruce budworm defoliation has not yet been quantified. In this article, we document the extent of stand breakdown and surface fuel acc...

Urban trees provide natural shade and moderate human exposure to solar ultraviolet radiation. To date, most studies quantifying UV attenuation by urban tree canopies have taken place in Australia, with no studies in North America. Few studies have utilized sensors sensitive to UV-B radiation, although the shorter wavelengths are more important in d...

Populations of native North American parasitoids attacking Agrilus Curtis (Coleoptera: Buprestidae) species have recently been considered as part of an augmentative biological control programme in an attempt to manage emerald ash borer, Agrilus planipennis Fairmaire, a destructive wood-boring beetle discovered in North America in 2002. We evaluate...

Agrilus planipennis Fairmaire (Col: Buprestidae) (EAB) has been spreading rapidly throughout North America, killing millions of ash trees, Fraxinus spp. L. (Oleaceae). Eradication is not viable, so biological control using natural enemies is now the leading management strategy. Little information is available on whether native parasitoids and preda...

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, a...

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

Understanding the potential outcomes of interactions between native insects and invasive plants is important for predicting the magnitude of effects caused by an invader in its new environment. Here, we investigate the ability of the native western leaf beetle, Chrysochus cobaltinus, and a hybrid of North American Chrysochus species, (hybrid of eas...

The invertebrates are the most diverse group in the world; they colonize almost all the ecosystems and certainly give many goods and services to the human beings. The invertebrates that live in the soil contribute consistently with changes in the ecosystemic functions, affecting directly: nutrients, cycle, change in biomass contain ecological nets...

It is important to develop efficient and cost-effective methods for monitoring the establishment and fitness of biological control agents. Understanding how simple and obtainable measurements of insects or their body parts relate to reproductive life-history traits could facilitate assessing the fitness of biological control agent populations in th...

Hypena opulenta, a moth native to Ukraine, was released in 2013–2014 as a biocontrol agent for pale swallow-wort Vincetoxicum rossicum, an invasive vine, in Ottawa, Ontario, Canada. Blacklight trapping and surveys of feeding damage showed that H. opulenta has successfully established, increased in abundance and spread up to 2.0 km.

Humans have now altered essentially every natural ecosystem in the world, and among the numerous consequences of anthropogenic global change, many of the Earth’s species are currently living under drastically different environmental and ecological conditions. On one hand, many species that once thrived in the wild are now threatened by extinction,...

The urban forest is a valuable ecosystem service provider, yet cities are frequently-degraded environments with a myriad of stressors and disturbances affecting trees. Vulnerability science is increasingly used to explore issues of sustainability in complex social-ecological systems, and can be a useful approach for assessing urban forests. The pur...

Emerald ash borer (EAB) is the most significant forest health challenge facing North America, with tens of millions of trees dead and dying as the beetle continues its spread to new areas. This article provides an overview of the biology of EAB and reports on the experience of Toronto, Canada, one of the hardest-hit urban centres, in North America....

High parasitism by a native parasitoid, Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae), has been reported on emerald ash borer (hereafter EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in North America. Use of this parasitoid in an augmentative biological control program has been proposed to slow the spread of EAB, yet in...

Spruce budworm, Choristoneura fumiferana (Clem.), defoliation has been shown to affect the occurrence of crown fire in Ontario, highlighting the need to better understand the driving factors of this effect on forest structure, including changes in fuel loading, type and position. Here, we investigate five boreal mixedwood sites within four zones th...

Human exposure to green space and vegetation is widely recognized to result in physical and mental health benefits; however, to date, the specific effects of tree cover, diversity, and species composition on student academic performance have not been investigated. We compiled standardized performance scores in Grades 3 and 6 for the collective stud...

Saproxylic insect assemblages are essential functional components of forest ecosystems that can be affected by forest management. We used a split-plot ANOVA design to analyze differences in selected saproxylic insects (all arthropod orders and dipteran and parasitic hymenopteran families) emerging from dead wood of sites with different logging hist...

The effect of high temperature on the performance of the spruce budworm (Choristoneura fumiferana) parasitoid Tranosema rostrale (Hymenoptera: Ichneumonidae), its polydnavirus (TrIV), and the immune reaction of its host.

Native insects can form novel associations with introduced invasive plants and use them as a food source. The recent introduction into eastern North America of a nonnative European vine, Vincetoxicum rossicum (Kleopow) Barbar., allows us to examine the initial response of a native chrysomelid beetle, Chrysochus auratus F., that feeds on native plan...

Data S1. Appendix S1. PRISMA diagram Appendix S2. References of studies included in meta‐analysis Appendix S3. Metadata of ‘Cravenetal_Earthworms_PlantDiversity.csv’ Appendix S4. Metadata of ‘Cravenetal_EffectSizes_Earthworms_PlantFunctGroups.csv’ Table S1. Studies included in meta‐analysis and additional information about each study Table S2...

Data S3. Cravenetal_Earthworms_PlantFunctionalGroups.csv Data file containing effect sizes of relationships between introduced earthworm communities and cover of plant functional groups of forest understory communities in North America.

Data S2. Cravenetal_Earthworms_PlantDiversity.csv Data file containing effect sizes of relationships between introduced earthworm communities and plant species diversity, evennness, and richness of forest understory communities in North America.

A growing understanding about the impacts of earthworms (Oligochaeta: Lumbricidae) on ecosystem processes and forest restoration necessitates an examination of their role in Canadian forests where they have become invasive. Little is known about the landscape scale responses of earthworm populations to different regional characteristics and vegetat...

The combination of biochar (BC) with compost has been suggested to be a promising strategy to promote plant growth and performance, but although " synergistic " effects have been stated to occur, full‐factorial experiments are few, and explicit tests for synergism are lacking. We tested the hypothesis that a combination of BC and spent mushroom sub...

Endoparasitoids face the challenge of overcoming the immune reaction of their hosts, which typically consists of encapsulation and melanisation of parasitoid eggs or larvae. Some endoparasitic wasps such as the solitary Tranosema rostrale (Hymenoptera: Ichneumonidae) that lay their eggs in larvae of the spruce budworm, Choristoneura fumiferana (Lep...

The temperature-dependent development and survival of immatures, as well as adult longevity and potential fecundity of the endoparasitoid Tranosema rostrale (Hymenoptera: Ichneumonidae) parasitizing spruce budworm Choristoneura fumiferana (Lepidoptera: Tortricidae) larvae was investigated under laboratory conditions at several constant temperatures...

Globally, biological invasions can have strong impacts on biodiversity as well as ecosystem functioning. While less conspicuous than introduced aboveground organisms, introduced belowground organisms may have similarly strong effects. Here, we synthesize for the first time the impacts of introduced earthworms on plant diversity and community compos...

Tranosema rostrale (Brischke) (Hymenoptera: Ichneumonidae) is an important parasitoid of low-density spruce budworm Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) populations. To investigate the effectiveness of this parasitoid in attacking low-density spruce budworm populations, we conducted a detailed laboratory study on its reprod...

The seasonal pattern of parasitism by a parasitoid can be influenced by many factors, such as interspecific competition and host instar preference. We conducted field and laboratory experiments to describe the seasonal pattern of parasitism of spruce budworm Choristoneura fumiferana (Clemens) larvae by Tranosema rostrale (Brischke), and to investig...

Multi-cohort management (MCM) that retains a range of stand structures (age and size class) has been proposed to emulate natural disturbance and improve management in the Nearctic boreal forest. Although MCM forests contain both single- and multi-aged stands of mixed tree sizes, little is known about how variable stand structure affects associated...

Sirex noctilio F. (Hymenoptera: Siricidae) is a woodwasp of pine trees that has recently invaded and established in North American forests. Although S. noctilio has had a limited impact in North America to date, there is some concern that it could have a significant impact on pine plantations, especially in the southeastern U.S.A. Moreover, there a...

Nutritional enhancement of crops using genetic engineering can potentially affect herbivorous pests. Recently, oilseed crops have been genetically engineered to produce the long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at levels similar to that found in fish oil; to provide a more sustain...

Total lipid (% dry weight) and FA composition (μg ∙ mg-1) of diets fed to the larval cabbage butterfly (n = 3) (DOCX)

Total lipid (%) and FA composition (% total FA) of diets fed to the larval cabbage butterfly (n = 12) (DOCX)

Total lipid (% dry weight) and FA composition (μg ∙ mg-1) of whole butterflies (n = 12) that were fed experimental diets during their larval stage (DOCX)

Total lipid (%) and FA composition (% total FA) of whole butterflies that were fed experimental diets during their larval stage (DOCX)

Under laboratory and field conditions in Ontario, Canada, we explored the natural history of Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae), an indigenous solitary endoparasitoid of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in North America. Adult P. sulcata emergence was ~20.2–23.9 days after host emergence at 21°C, with P...

Biological control has been an important tactic in the management of Canadian forests for over a century, but one that has had varied success. Here, we review the history of biological control programmes using vertebrate and invertebrate parasitoids and predators against insects in Canadian forests. Since roughly 1882, 41 insect species have been t...

Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae) is a North American parasitoid now using Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) as a novel host, and may prove useful in biocontrol. Unfortunately, information is lacking regarding mating and the presence of pheromones, which may be important when attempting to exploit this...

Evidence-based conservation seeks to incorporate sound scientific information into environmental deci-sion making. The application of this concept in urban forest management has tremendous potential, but to date has been little applied, largely because existing scientific studies emphasize the importance of urban forests in large-scale ecological a...

This volume (71 chapters), the fifth in a series documenting biological control programmes in Canada, presents new information on specific insect, weed or plant diseases, some of which are updates of on-going studies on historical biological control projects while other chapters report on biological control efforts for new emerging invasive alien s...

This volume (71 chapters), the fifth in a series documenting biological control programmes in Canada, presents new information on specific insect, weed or plant diseases, some of which are updates of on-going studies on historical biological control projects while other chapters report on biological control efforts for new emerging invasive alien s...

Multi-cohort forest management (MFM) is a natural disturbance emulation strategy for boreal forests that recommends a diversification of silvicultural techniques to emulate three broad successive phases of post-fire development, termed "cohort classes" Here, for boreal mixedwood (n = 308) and black spruce (n = 108) stands of northeastern Ontario, w...

Earthworm invasions in North American temperate forests cause considerable changes to soil and litter horizons, which can lead to changes in soil biogeochemistry and plant communities. These ecosystem changes have complex causal relationships, and the cascades of indirect effects from earthworm burrowing and feeding may have larger net effects on s...

An established population of the exotic woodwasp Sirex noctilio Fabricius (Hymenoptera: Siricidae) was first detected in North America in 2004. In order to develop survey guidelines for the detection of this major pest of Pinus Linnaeus species in the Southern Hemisphere, we examined 231 Pinus sylvestris biweekly to establish the timing and spatial...