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Purpose Ambulance services staff worldwide have long been at risk of encountering violence and aggression directed towards them during their work. Verbal forms of violence and aggression are the most prevalent form, but sometimes incidents involve physical injury, and on rare occasions homicides do occur. Exposure to such violence and aggression can have a lasting negative impact upon ambulance staff and has been associated with increased levels of stress, fear, anxiety, emotional exhaustion, depersonalisation and burnout syndrome. Despite the significance of this issue, little progress has been made to tackle it. The purpose of this paper is to describe this multi-agency approach being taken in Wales (UK) to reduce such harms from violence and aggression directed towards ambulance services staff. Design/methodology/approach An interpretative post-positivist narrative methodology and policy analysis approach was followed. Snowball methods of gathering data were used to construct this narrative involving meetings, telephone calls, review of policy documents, legislation and academic literature. Findings The authors report how tackling violence and aggression directed towards emergency workers has become a priority within Wales (UK), resulting in policy developments and initiatives from groups such as the UK and Welsh Government, the Welsh Ambulance Services National Health Services (NHS) Trust, Health Boards, the NHS Wales Anti-Violence Collaborative and the Joint Emergency Services Group (JESG) in Wales. This has included changes in legislation such as the Assaults on Emergency Workers (Offences) Act 2018 that came into force on 13th November 2018 and policy changes such as the obligatory responses to violence in health care and the JESG #WithUsNotAgainst Us campaign. Our study however reflects the complexity of this issue and the need for further high-quality research. Originality/value The experiences and activities of Wales (UK) reported in this paper adds to the international body of knowledge and literature on violence and aggression directed towards ambulance services staff.

For capital-breeding insects, all resources available for adult metabolic needs are accumulated during larval feeding. Therefore, body size at adult eclosion represents the total energetic capacity of the individual. For female capital breeders, body size is strongly correlated with lifetime fecundity, while in males, body size, which correlates with fitness, is less understood. In capital-breeding species with wingless, flightless, or dispersal-limited females, flight potential for male Lepidoptera has important implications for mate-finding and may be correlated with body size. At low population densities, failure to mate has been identified as an important Allee effect and can drive the success or failure of invasive species at range edges and in species of conservation concern. Th capital-breeding European subspecies of Lymantria dispar (L.), was introduced to North America in 1869 and now ranges across much of eastern North America. In L. dispar, females are flightless and mate-finding is entirely performed by males. We quantified male L. dispar flight capacity and propensity relative to morphological and physiological characteristics using fixed-arm flight mills. A range of male body sizes was produced by varying the protein content of standard artificial diets while holding other dietary components constant. Wing length, a proxy for body size, relative thorax mass, and forewing aspect were all important predictors of total flight distance and maximum speed. These results have important implications for mate-finding and invasion dynamics in L. dispar and may apply broadly to other capital-breeding insects.

Many caterpillars exhibit patterns of ultraviolet (UV) fluorescence, although its purpose is unclear. We used realistic plasticine models of a fluorescing caterpillar species, the Polyphemus moth, Antheraea polyphemus (Lepidoptera; Saturniidae), adorned with fluorescent paint treatments and unpainted controls to quantify bird predation in two hardwood forested regions of New York State, United States of America. In separate field studies, significantly more birds struck deployed model caterpillars that had no UV fluorescence. More strikes on unpainted and clear paint treatments suggest paint itself did not impact predation, whereas similar predation attempts on bird and human-visible fluorescent dummies suggest that UV fluorescence and not UV reflectance was responsible for the observed effect. A second study found the dummy’s location on the tree was also important, but the low number of bird strikes limited analyses. Although our results do not identify a mechanism, fluorescence may function to deter or avoid predation. Our study contributes to a growing body of work investigating the importance of UV patterns in arthropods and highlights a potentially fruitful area of future research on predator–prey relations.

As the global climate changes, high and low temperature extremes can drive changes in species distributions. Across the range of a species, thermal tolerance can experience plasticity and may undergo selection, shaping resilience to temperature stress. In this study, we measured variation in the lower thermal tolerance of early instar larvae of an invasive forest insect, Lymantria dispar dispar L. (Lepidoptera: Erebidae), using populations sourced from the climatically diverse invasion of the Eastern United States. In two chill coma recovery experiments, we recorded recovery time following a period of exposure to a non-lethal cold temperature. A third experiment quantified growth responses after chill coma recovery to evaluate sublethal effects. Our results indicate that cold tolerance is linked to regional climate, with individuals from cold climate populations recovering faster from chill coma. While this geographic gradient is seen in many species, detecting this pattern is notable for an introduced species founded from a single point-source introduction. We demonstrate that the cold temperatures used in our experiments occur in nature from cold snaps after spring hatching, but negative impacts to growth and survival appear low. We expect that population differences in cold temperature performance manifest more from differences in temperature-dependent growth than acute exposure. Evaluating intraspecific variation in cold tolerance increases our understanding of the role of climatic gradients on the physiology of an invasive species, and contributes to tools for predicting further expansion.Summary StatementChill coma recovery experiments demonstrate geographic variation in cold temperature tolerance for a widespread invasive species, and the risk of early season exposure differs across the invasion front.

Temperature and its impact on fitness are fundamental for understanding range shifts and population dynamics under climate change. Geographic climate heterogeneity, behavioural and physiological plasticity, and thermal adaptation to local climates makes predicting the responses of species to climate change complex. Using larvae from seven geographically distinct wild populations in the eastern United States of the non-native forest pest Lymantria dispar dispar (L.), we conducted a simulated reciprocal transplant experiment in environmental chambers using six custom temperature regimes representing contemporary conditions near the southern and northern extremes of the US invasion front and projections under two climate change scenarios for the year 2050. Larval growth rates increased with climate warming compared to current thermal regimes and responses differed by population. A significant population-by-treatment interaction indicated that growth rates increased more when a source population experienced the warming scenarios for their region, especially for southern populations. Our study demonstrates the utility of simulating thermal regimes under climate change in environmental chambers and emphasizes how the impacts from future increases in temperature can be heterogeneous due to geographic differences in climate-related performance among populations.

American chestnut (Castanea dentata [Marsh.] Borkh.) was once the dominant hardwood species in Eastern North America before an exotic fungal pathogen, Cryphonectria parasitica (Murrill) Barr, functionally eliminated it across its range. One promising approach toward restoring American chestnut to natural forests is development of blight-tolerant trees using genetic transformation. However, transformation and related processes can result in unexpected and unintended phenotypic changes, potentially altering ecological interactions. To assess unintended tritrophic impacts of transgenic American chestnut on plant-herbivore interactions, gypsy moth (Lymantria dispar L.) caterpillars were fed leaf disks excised from two transgenic events, Darling 54 and Darling 58, and four control American chestnut lines. Leaf disks were previously treated with an LD50 dose of either the species-specific Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV) or the generalist pathogen Bacillus thuringiensis subsp. kurstaki (Btk). Mortality was quantified and compared to water blank controls. Tree genotype had a strong effect on the efficacies of both pathogens. Larval mortality from Btk-treated foliage from only one transgenic event, Darling 54, differed from its isogenic progenitor, Ellis 1, but was similar to an unrelated wild-type American chestnut control. LdMNPV efficacy was unaffected by genetic transformation. Results suggest that although genetic modification of trees may affect interactions with other nontarget organisms, this may be due to insertion effects, and variation among different genotypes (whether transgenic or wild-type) imparts a greater change in response than transgene presence.

Engaging students in hands-on inquiry helps them develop skills associated with the scientific process. Development of simple experiments using model caterpillars can provide an experiential demonstration of the scientific process and ecological principles for high school students. Caterpillar models are formed from plasticine, a nontoxic, nondrying modeling clay, and are an excellent tool for quantifying relative predation rates by birds, small mammals, and invertebrates. Lifelike surrogate larvae are glued to vegetation for short periods (one week) and retain identifiable marks (beak, teeth, mandible imprints) following predator attack. This technique is simple, inexpensive, and provides rapid and clear results, rendering it a highly effective method of inquiry for high school students. Students can use these methods to ask a variety of research questions, such as comparison of predation in nearby habitats (park vs. backyard), vegetation (tree vs. shrub), season (spring vs. fall), or coloration (aposematic vs. camouflage). For many students, this may be one of few opportunities at the high school level to investigate science “in the field” and integrate scientific practices, such as the scientific method and inquiry, in an authentic research experience. Participants develop their scientific reasoning skills through creation of research questions and interpretation of results. They learn experimental technique, build field skills, and work collaboratively. This experiment aligns with the Next Generation Science Standards.

Temperature provides important physiological constraints that can influence the distribution of an invasive species. Gypsy moth (Lymantria dispar L.) is a generalist defoliator in North America and supraoptimal temperatures (above the optimal for developmental rate) have been implicated in range dynamics at the southern invasion front in West Virginia and Virginia. We sourced egg masses from the Appalachian Mountains (AM), where the gypsy moth range is expanding, from the Coastal Plain (CP), where range retraction is occurring, and from a long-established population in New York (NY) and conducted a reciprocal transplant experiment to compare development and fitness components among these populations at two sites along the southern invasion front. We found evidence of sublethal effects from rearing in the CP, with decreased pupal mass and fewer eggs compared to individuals reared in the AM, but little difference between source populations in developmental traits. The AM and NY populations did experience reductions in egg viability under a southern winter at the CP site compared to control wintering conditions, while the CP egg masses had equivalent survival. This study provides empirical support for negative fitness consequences of supraoptimal temperatures at the southern range edge, consistent with patterns of range retraction and spread in the region, as well as suggesting the potential for local adaptation through variation in egg survival. Our work illustrates that sublethal effects from high temperature can be an important factor determining the distribution of invasive species under current and future climates.

Invasive woody plants from Europe and Asia tend to be more productive than co-occurring native species in deciduous forests of Eastern North America, but community-scale drivers of invasion success remain unknown. If increased productivity in invaders relative to natives comes at the expense of reduced relative allocation to defenses, generalist herbivores may preferentially consume invasive species, potentially reducing the effectiveness of invader growth advantage. We compared leaf traits related to herbivory (nitrogen concentration, total phenolics, cellulose and lignin concentrations, and leaf dry matter content) in 20 phylogenetically paired native and non-native, invasive species and evaluated species palatability to two generalist herbivores: one non-native (European gypsy moth, Lymantria dispar) and one native (fall webworm, Hyphantria cunia). We also evaluated potential physiological tradeoffs between defense-related leaf traits, leaf production, and carbon storage in this group of species. Invasive plants had higher leaf N and lignin concentrations than related native species (0.5% and 5%, respectively), but gypsy moth and fall webworm growth were not associated with plant nativity. Plant defense traits did not predict differences in gypsy moth growth, but fall webworm growth was marginally negatively associated with leaf N. We found no evidence of tradeoffs between defense-related leaf traits, leaf production, and carbon storage, indicating a limited role for carbon-based tradeoffs relating to growth and herbivory in these species, although other unmeasured carbon pools including reproduction may impact these relationships. Woody invaders continue to spread in Eastern North American forest understories, but we found no evidence of inhibition or facilitation by generalist insect herbivores, despite differences among species in leaf traits associated with defense.

Large-scale disturbances such as ice storms may increase in frequency and intensity as climate changes. While disturbances are a natural component of forest ecosystems, climatically driven alteration to historical patterns may impart fundamental change to ecosystem function. At Hubbard Brook Experimental Forest, NH, experimental ice storms of varying severity were applied to replicate plots of mature northern hardwoods to quantify their effects on forested ecosystems. We assessed ice storm treatment effects on insectivorous foliage-gleaning birds and evaluated insectivore predation on model caterpillars in the understory vegetation. These birds are charismatic, of conservation concern, and are major predators of caterpillars. In turn, lepidopterans are the dominant herbivores in temperate forests and are integral to ecosystem function. We predicted that avian abundance would increase due to additional structural heterogeneity caused by ice treatments, with a concomitant increase in caterpillar predation. Point counts were used to measure insectivorous bird activity in the ice storm experiment plots and additional control plots before and after treatments. We deployed and retrieved plasticine model caterpillars and estimated predation from characteristic marks to these surrogates. Abundance of foliage-gleaning birds was higher in the ice storm plots and birds responded to treatments as a single diffuse disturbance rather than on an individual plot level. All species except one were observed both before and after the ice treatments. Surprisingly, predation on caterpillar models was unaffected by ice storm treatments but rather was a function of caterpillar density. The increase in avian abundance in the ice storm treatment plots corroborates other studies of bird responses to relatively small-scale disturbances in forests and the limited change in species composition was expected given the plot size. We conclude that ice storms may provide beneficial changes for foliage-gleaning birds in the growing season following the disturbance.

• Maintenance and restoration of forest ecosystems will be key to achieving necessary carbon sequestration goals, protecting biodiversity, and supporting healthy economies and societies. • Forest ecosystems are increasingly threatened by non-native forest insects and phytopathogens. • A portion of these pests are able to overcome prevention and containment efforts and become established in naive ecosystems. • Once established these pests pose a long-term large-scale threat to forest ecosystems, which current policy and response frameworks are poorly equipped to address. • We propose the creation of a federal Center for Forest Pest Control and Prevention to implement end-to-end responses to forest pest invasions using an ecologically-informed framework that fully integrates host tree resistance development and deployment.

Quantifying the strength of interactions among introduced and native species across space and time is critical in understanding biological invasions as they can attenuate or amplify the magnitude of impact. The European woodwasp, Sirex noctilio F., a global threat to pines, is a recent invader to North America. It attacks and kills primarily Pinus resinosa and Pinus sylvestris, and encounters a diverse assemblage of potential competitors for this resource. We quantified spatial colonization patterns of this woodwasp and resident competitors including scolytine bark beetles, woodboring cerambycid and buprestid beetles, and the fungal root rot diseases Armillaria and Heterobasidion across an 80 year old pine plantation over 4 years. All xylophages were spatially aggregated, but only on a localized scale of 15–20 m. Colonizers occurred non-randomly within trees, with S. noctilio negatively or neutrally associated with all other colonizing agents, whereas all other insect and root rot colonizers were mostly positively co-associated. An autologistic regression with spatially-weighted variables indicated the probability of a dead tree exhibiting symptoms of S. noctilio attack was positively associated with tree density, host species (P. sylvestris), and density of S. noctilio-attacked trees from the current and previous year. Interspecific stand patterns were weaker; probability of attack was negatively associated only with root rot pathogens. Across spatial scales, there were mixed (woodborers) and neutral (bark beetles) associations between S. noctilio and other co-colonizing insects. Our results suggest that competitive interactions with resident species may be contributing to the limited success of S. noctilio in North America, but are unlikely to be driving it by themselves.

Variation in thermal performance within and between populations provides the potential for adaptive responses to increasing temperatures associated with climate change. Organisms experiencing temperatures above their optimum on a thermal performance curve exhibit rapid declines in function and these supraoptimal temperatures can be a critical physiological component of range limits. The gypsy moth, Lymantria dispar (L.) (Lepidoptera: Erebidae), is one of the best-documented biological invasions and factors driving its spatial spread are of significant ecological and economic interest. The present study examines gypsy moth sourced from different latitudes across its North American range for sensitivity to high temperature in constant temperature growth chamber experiments. Supraoptimal temperatures result in higher mortality in northern populations compared with populations from the southern range extent (West Virginia and coastal plain of Virginia, U.S.A.). Sublethal effects of high temperature on traits associated with fitness, such as smaller pupal mass, are apparent in northern and West Virginia populations. Overall, the results indicate that populations near the southern limits of the range are less sensitive to high temperatures than northern populations from the established range. However, southern populations are lower performing overall, based on pupal mass and development time, relative to northern populations. This suggests that there may be a trade-off associated with decreased heat sensitivity in gypsy moth. Understanding how species adapt to thermal limits and possible fitness trade-offs of heat tolerance represents an important step toward predicting climatically driven changes in species ranges, which is a particularly critical consideration in conservation and invasion ecology.

Following establishment in a new environment, invasive species expand their range through stratified diffusion, the coupling of local growth and spatial spread with long-distance movement of propagules that found new colonies. Consequently, the stages of arrival and establishment serially repeat until the entire habitat susceptible to invasion is occupied. An empirical example of such a phenomenon is the gypsy moth, Lymantria dispar (L.), invasion of northeastern Minnesota. Under a regional management program, a trapping grid is deployed along the L. dispar leading edge to detect male moth presence and inform management decisions. However, the presence of moths does not always indicate reproducing populations, and moths dispersing from populations behind the front can obscure the presence of latent invasions. We analyzed trapping data during the arrival and establishment of L. dispar in this region (2000–2012), supplemented with sentinel trap data to ascertain the timing of male moth flight (2005–2009), and derived yearly phenological predictions for male moth flight. We also used a male wing morphology metric (2007–2009) to further quantify spatial and temporal patterns associated with the L. dispar invasion. We provide evidence of an established L. dispar population when analyses suggest spatial randomness in trap catch data, and how the presence of phenologically distinct, immigrating adult moths from source populations outside of Minnesota recorded from sentinel traps could lead to the overestimation of the abundance of an established population. This work highlights the complexity of the initial invasion process even in a well-studied system for which a sensitive monitoring program exists.

We collected naturally infested Pinus resinosa Aiton (Pinaceae) and P. sylvestris Linnaeus to investigate phenological patterns and quantify parasitism by a suite of native hymenopteran parasitoids on two woodwasps (Hymenoptera: Siricidae): the invading non-native European woodwasp, Sirex noctilio Fabricius, and a co-colonising native, S. nigricornis Fabricius. We sampled a total of 76 trees from two field sites in 2010 and seven sites in 2011. In raw abundance, S. noctilio outnumbered S. nigricornis by 2:1 in 2010 and by 7.5:1 in 2011. We collected the egg/early instar parasitoid, Ibalia leucospoides ensiger Norton (Hymenoptera: Ibaliidae); four species of Rhyssinae (Hymenoptera: Ichneumonidae) late larval parasitoids; and Pseudorhyssa nigricornis (Ratzeburg) (Hymenoptera: Ichneumonidae), a cleptoparasitoid of rhyssines. Variation in siricid and parasitoid species assemblage and abundance was explained primarily by site, with tree-level factors playing a secondary role. Parasitism was significantly lower in P. sylvestris (13.6%±4.1 SE), a naturalised pine from Europe, than in the native P. resinosa (28.5%±5.0). Total parasitism was 27.6%±5.0 in 2010 and 20.9%±4.7 in 2011. This study represents the most robust analysis of the diverse woodwasp and parasitoid assemblage infesting pines in North America.

Establishing host-parasitoid relationships is challenging for cryptic insects feeding deep in the xylem tissue of trees. Sirex noctilio is a xylophagous feeder and recent invader of North America that co-occurs in pines (Pinus) with a native siricid (Sirex nigricornis) and a suite of shared hymenopteran parasitoids. This insect has a long history as a destructive pest in Southern Hemisphere pine plantations. 2 To establish explicit trophic linkages between native hymenopteran parasitoids and two species of woodwasp (Sirex) in North America, a polymerase chain reaction assay was developed to amplify mitochondrial DNA that was restriction digested with the aim of identifying species. The assay was used to identify species of Sirex from cadavers and gut contents from different parasitoid stages with the aim of establishing host-parasitoid relationships. 3 The host woodwasp species was identified successfully from parasitoid gut contents collected from larvae, pupae and adults. Across all parasitoid life stages, woodwasp host was identified in 52.9% of ibaliid parasitoids and 78.5% of rhyssine parasitoids. Host was successfully identified from 88.1% of associated siricid cadavers. 4 These results demonstrate the utility of molecular techniques to verify host-parasitoid associations that previously had only been inferred. Development of molecular tools is a rapid and crucial tool for establishing trophic linkages and is particularly useful in situations involving non-native species with cryptic lifestyles.

The European gypsy moth (Lymantria dispar L.) was first introduced to Massachusetts in 1869 and within 150 years has spread throughout eastern North America. This large-scale invasion across a heterogeneous landscape allows examination of the genetic signatures of adaptation potentially associated with rapid geographical spread. We tested the hypothesis that spatially divergent natural selection has driven observed changes in three developmental traits that were measured in a common garden for 165 adult moths sampled from six populations across a latitudinal gradient covering the entirety of the range. We generated genotype data for 91,468 single nucleotide polymorphisms based on double digest restriction-site associated DNA sequencing and used these data to discover genome-wide associations for each trait, as well as to test for signatures of selection on the discovered architectures. Genetic structure across the introduced range of gypsy moth was low in magnitude (FST = 0.069), with signatures of bottlenecks and spatial expansion apparent in the rare portion of the allele frequency spectrum. Results from applications of Bayesian sparse linear mixed models were consistent with the presumed polygenic architectures of each trait. Further analyses indicated spatially divergent natural selection acting on larval development time and pupal mass, with the linkage disequilibrium component of this test acting as the main driver of observed patterns. The populations most important for these signals were two range-edge populations established less than 30 generations ago. We discuss the importance of rapid polygenic adaptation to the ability of non-native species to invade novel environments.

Defoliating insects are a major factor impacting tree growth in temperate and boreal forests, but the effects of climate change on the severity and frequency of outbreaks of these insects are not well understood. Dendrochronological reconstruction of forest tent caterpillar (Malacosoma disstria) outbreaks on trembling aspen (Populus tremuloides) in southwestern Manitoba, Canada, from 1851 to 2010 was used to examine the effects of changes in temperature, incident surface‐level solar radiation, and drought severity on the cyclicity, frequency, and severity of outbreaks. Outbreak severity was determined by comparing the tree‐ring widths of trembling aspen with those of white spruce (Picea glauca), which is not a forest tent caterpillar host. Wavelet analysis suggested the cyclicity of outbreaks increased after 1930. From 1930 to 2010, the dominant period length of outbreak cycles steadily increased over time from three to seven years, coinciding with long‐term declines in drought severity. The strength of forest tent caterpillar suppression of trembling aspen growth in a given year was inversely related to incident solar radiation and drought severity during late spring (the larval feeding period) of the same year. The effect of late spring drought on the impact of forest tent caterpillar on ring growth differed from that of summer drought. There was a nonlinear relationship between growth suppression in a given year and summer drought severity in the previous year; slightly above‐average drought severity was associated with reduced impacts of the defoliator, whereas severe drought was associated with intense growth suppression. Strong suppression of aspen growth observed during outbreaks from 1983 to 2010 may be partly explained by observed long‐term trends of decreasing atmospheric transmittance of solar radiation (a phenomenon termed “global dimming”) and increasing soil moisture availability during late spring. However, as the severity and frequency of summer droughts are expected to increase over the 21st century, the nonlinear relationship between summer drought severity and growth suppression the following year suggests a future in which summer droughts precede severe outbreaks that threaten the health of boreal forest hardwood trees.

Thermal regimes can diverge considerably across the geographic range of a species, and accordingly, populations can vary in their response to changing environmental conditions. Both local adaptation and acclimatization are important mechanisms for ectotherms to maintain homeostasis as environments become thermally stressful, which organisms often experience at their geographic range limits. The spatial spread of the gypsy moth (Lymantria dispar L.) (Lepidoptera: Erebidae) after introduction to North America provides an exemplary system for studying population variation in physiological traits given the gradient of climates encompassed by its current invasive range. This study quantifies differences in resting metabolic rate (RMR) across temperature for four populations of gypsy moth, two from the northern and two from southern regions of their introduced range in North America. Gypsy moth larvae were reared at high and low thermal regimes, and then metabolic activity was monitored at four temperatures using stop-flow respirometry to test for an acclimation response. For all populations, there was a significant increase in RMR as respirometry test temperature increased. Contrary to our expectations, we did not find evidence for metabolic adaptation to colder environments based on our comparisons between northern and southern populations. We also found no evidence for an acclimation response of RMR to rearing temperature for three of the four pairwise comparisons examined. Understanding the thermal sensitivity of metabolic rate in gypsy moth, and understanding the potential for changes in physiology at range extremes, is critical for estimating continued spatial spread of this invasive species both under current and potential future climatic constraints.

The effects of long-term mass rearing of laboratory insects on ecologically relevant traits is an important consideration when applying research conclusions to wild populations or developing management strategies. Laboratory strains of the gypsy moth, Lymantria dispar (L.), an invasive forest pest in North America, have been continuously reared since 1967. Selection on these strains has enhanced a variety of traits, resulting in faster development, shorter diapause, and greater fecundity. As in many mass-reared insects, laboratory strains of the gypsy moth are also reared exclusively on artificial diets that lack much of the phytochemical and nutritional complexity associated with natural foliage. We tested for differences in growth and development of wild gypsy moth populations from across the invasive range in comparison to laboratory strains when reared on artificial diet and a preferred foliage host species, northern red oak (Quercus rubra L.). Overall, caterpillars reared on foliage had higher survival and faster development rates, with smaller differences among populations. When reared on artificial diet, laboratory strains had the highest performance as expected. The response from the wild populations was mixed, with two populations performing poorly on artificial diet and another performing nearly as well as the laboratory strains. Performance on diet was enhanced when larvae received cubed portions changed regularly, as opposed to filled cups. Understanding these relationships between food source and population performance is important for informing studies that examine population comparisons using wild and laboratory-reared strains.

Rhyssa crevieri (Provancher), a primary parasitoid of Siricidae wasps, and the Holarctic poemeniine ichneumonid, Pseudorhyssa nigricornis (Ratzeburg), a cleptoparasitoid of Siricidae via its parasitoids (Ichneumonidae: Rhyssinae), were reared from two stands of Scots pine (Pinus sylvestris L.) and red pine (P. resinosa Ait.) infested with the exotic siricid Sirex noctilio F. near Tully (Onondaga Co.), New York, in 2010. Previously, P. nigricornis has been recorded from the primary siricid parasitoids Rhyssa persuasoria (in Europe and North America) and R. howdenorum Townes and Townes and R. lineolata (Kirby) (in North America). Peak emergence of P. nigricornis occurred in early May concurrently with R. persuasoria and R. crevieri. A second peak occurred in late May, which overlapped peak emergence of R. lineolata and Megarhyssa nortoni (Cresson). Although 14 individuals of two native siricids, Sirex nigricornis F. and S. edwardsii Brulle, emerged from sampled trees, the number of S. noctilio rec...

American chestnut [Castanea dentata (Marshall) Borkhausen], a canopy dominant species across wide swaths of eastern North America, was reduced to an understory shrub after introduction of the blight fungus [Cryphonectria parasitica (Murrill) Barr] in the early 1900s. Restoration of American chestnut by using biotechnology is promising, but the imprecise nature of transgenesis may inadvertently alter tree phenotype, thus potentially impacting ecologically dependent organisms. We quantified effects of genetic engineering and fungal inoculation of trees on insect herbivores by using transgenic American chestnuts expressing an oxalate oxidase gene and wild-type American and Chinese (C. mollissima Blume) chestnuts. Of three generalist folivores bioassayed, only gypsy moth [Lymantria dispar (L.)] was affected by genetic modification, exhibiting faster growth on transgenic than on wild-type chestnuts, whereas growth of polyphemus moth [Antheraea polyphemus (Cramer)] differed between wild-type species, and fall webworm [Hyphantria cunea (Drury)] performed equally on all trees. Inoculation of chestnuts with blight fungus had no effect on the growth of two herbivores assayed (polyphemus moth and fall webworm). Enhanced fitness of gypsy moth on genetically modified trees may hinder restoration efforts if this invasive herbivore's growth is improved because of transgene expression.

In northern forests dominated by aspen (Populus spp.), the duration of outbreaks of forest tent caterpillar (Malacosoma disstria Hubner) has been reported to increase with forest fragmentation. This relationship has not been tested in other forest types affected by this widespread native defoliator. From 2002 to 2007, a large-scale outbreak of this insect in the northeastern United States defoliated millions of hectares, with sugar maple (Acer saccharum Marsh.) the primary host. We used digital defoliation maps generated from aerial surveys and national land cover data to assess the effect of fragmentation on outbreak duration in areas of NY, MA, VT, and NH. We found that outbreak duration increased with forest cover and decreased with the forest edge, in opposition to the pattern previously reported for aspen-dominated forests in Canada. This pattern was significant from plot sizes ranging from 100 m to 1000 m in radius. The relationship between FTC and its natural enemies, which was postulated to underlie the effect of fragmentation on outbreaks in aspen forests, may be affected differently in northern hardwood forests, or other factors may be more important in determining outbreak duration in this forest type.

Cerebral palsy (CP) is a collective term used to describe a diverse group of neurological disorders characterized by varying degrees of motor, sensory, and intellectual impairment. The condition was first described in 1862 by an orthopaedic surgeon, William Little. He observed that some children, born prematurely or after a complicated labour or delivery, developed stiff spastic legs and postulated that this was caused by cerebral hypoxia at the time of birth. In the late 1890s, Sigmund Freud postulated that many cases of CP were caused, not by complications during the peripartum period, but by abnormalities arising during fetal development. The true significance of Freud’s observations was not fully realized until the 1980s when the National Institute of Neurological Disorders and Stroke published a perinatal study which suggested that complicated deliveries could only account for 10% of all CP cases. The life expectancy of many patients with CP now extends into adulthood and they frequently present to both specialized and general hospitals for anaesthesia and surgery.

We review the observed and potential effects of climate change on native fauna of forests in northeastern North America by focusing on mammals, birds, amphibians, and insects. Our assessment is placed in the context of recent regional-scale climate projections. Climate change, particularly in recent decades, has affected the distribution and abundance of numerous wildlife species. Warming temperatures, alterations to precipitation regimes, seasonality, and climatic extremes are projected to affect species directly or indirectly in each of the focal taxa. Greatest climate change will occur during winter, and the survival of winter-active species as well as the survival, distribution, and abundance of hibernating mammals, amphibians, resident birds, and diapausing insects may be altered. Even under low emissions scenarios, effects on native fauna may be profound, affecting iconic species, endangered species, and species that provide economically valuable services, such as pollination and regulation of insect populations. However, much research that is essential to assessing the effects of climate change on the native fauna of northeastern forests remains to be done. Research that reveals causal mechanisms and relates these findings to population and community level processes will be most valuable.

A seminal paper by Howarth (Proc Hawaii Entomol Soc 24:239–244, 1983) entitled “Classical biological control: Panacea or Pandora’s Box” ignited a sometimes acrimonious debate over the relative safety of introductions for classical biological control. Extolled for years as environmentally benign, the litany of negative non-target effects profiled by Howarth heightened awareness of this issue. Several factors have muddied this debate including the conflation of frequency of effects with their strength, grouping the effects of disparate biological control agents together, and the lack of quantitative data on either side of the argument. Here, I examine the potential for non-target effects among insect parasitoids, the most common group used for biological control of arthropods. In response to calls for better quantitative studies, I highlight three different techniques, quantitative food webs, life table analysis, and experimental populations, respectively, to quantitatively assess or reassess non-target effects in different systems. I also explore three methodological approaches employed to ascertain the strength of competitive interactions between native and introduced parasitoids, a potential non-target effect that has received little attention in the literature. These types of studies may greatly increase our understanding of the nature of non-target interactions with introduced parasitoids and bring more rigor to a debate often dominated by rhetoric.

We examined the effects of fertilization and gypsy moth defoliation on condensed tannin concentration (%CT) of hybrid poplar (Populus × canadensis cv ‘Eugeneii’) fine roots in the summers of 1997 and 1998. This factorial experiment included two defoliation treatments (defoliated and a foliated control) and fertilization treatments (100 kg nitrogen (N) ha −1 and an unfertilized control). Gypsy moth (Lymantria dispar L.) populations were experimentally increased to obtain defoliation in the summers of 1996, 1997 and 1998; fertilization subplots were supplemented with NH 4 NO 3 (100 kg N ha −1 ) in the spring of each year. Despite the severity of defoliation, the effects were small, and significant on only two sampling dates: in May 1997, when fine root %CT was 23% lower in the defoliated trees, and in November 1997, when trees in the defoliated unfertilized plots had 35% higher root %CT than trees in all other plots. Defoliation effects on root %CT did not follow the same seasonal pattern as defoliation effects on root starch content, N uptake capacity or leaf %CT. Regulation of root condensed tannin concentration appeared to be partially uncoupled from these traits. The small transient effects on root defense reflect the resilience of this early successional tree to severe early season defoliation.

Recent attention has focused on the harmful effects of introduced biological control agents on nontarget species. The parasitoid Compsilura concinnata is a notable example of such biological control gone wrong. Introduced in 1906 primarily for control of gypsy moth, Lymantria dispar, this tachinid fly now attacks more than 180 species of native Lepidoptera in North America. While it did not prevent outbreaks or spread of gypsy moth, we present reanalyzed historical data and experimental findings suggesting that parasitism by C. concinnata is the cause of the enigmatic near-extirpation of another of North America's most successful invaders, the browntail moth (Euproctis chrysorrhoea). From a range of approximately 160,000 km2 a century ago, browntail moth (BTM) populations currently exist only in two spatially restricted coastal enclaves, where they have persisted for decades. We experimentally established BTM populations within this area and found that they were largely free of mortality caused by C. concinnata. Experimental populations of BTM at inland sites outside of the currently occupied coastal enclaves were decimated by C. concinnata, a result consistent with our reanalysis of historical data on C. concinnata parasitism of the browntail moth. The role of C. concinnata in the disappearance of browntail moth outside these enclaves has not been reported before. Despite the beneficial role played by C. concinnata in reversing the browntail moth invasion, we do not advocate introduction of generalist biological control agents. Our findings illustrate that the impact of such organisms can be both unpredictable and far-reaching.

Paediatric anaesthesia should be a positive experience for both the child and the anaesthetist. A careful and considerate approach to the child during their preoperative assessment will help to achieve this aim. This article emphasizes the approach to preoperative assessment in children, as well as specific aims to gain information from the visit. The important parts of patient history and examination are noted, including those specific to children, such as perinatal history, rashes, immunizations and upper respiratory tract infections. Guidelines on preoperative investigations, starvation times, the ‘innocent’ murmur and doses of premedication are suggested. The preoperative assessment is a time for the anaesthetist to form a plan for anaesthesia, and then explain this plan to the child and parent or guardian. This may include consent for various procedures as well as full explanation of what the child and guardian should expect. The experiences will be coloured by past events as well as preconceptions of the child and guardian; the preoperative assessment is an invaluable time to address these preconceptions. The importance of the preoperative visit and exchange of information can not be exaggerated. This article gives a structured approach to gaining information and advice on achieving and executing a plan for anaesthesia.

The forest tent caterpillar, Malacosoma disstria Hubner (Lepidoptera: Lasiocampidae), is distributed throughout North American hardwood forests. Although considered polyphagous, regional populations tend to use only a few host species for oviposition, suggesting that M. disstria is more oligophagous than commonly thought. We tested this premise using larvae from Manitoba, Canada; Michigan; and Louisiana in a factorial, reciprocal transplant experiment. Pupal mass, development time, and survival were recorded for each population after rearing larvae in Louisiana on three primary hosts used by southern populations (water tupelo, Nyssa aquatica L.; sweetgum, Liquidambar styraciflua L.; and water oak, Quercus nigra L.) and in Michigan on three northern host trees (red oak, Quercus rubra L.; trembling aspen, Populus tremuloides Michaux; and sugar maple, Acer saccharum Marshall). Manitoba, Canada and Michigan populations had the highest pupal mass, best survival, and most rapid development on trembling aspen and red oak, both northern species. Louisiana larvae attained the highest pupal mass on water tupelo, a primary host across the Gulf States. Northern populations grew poorly on water tupelo, whereas Louisiana caterpillars had the smallest pupal mass and poorest survival on sugar maple. Both red and water oaks were acceptable hosts for all three populations. Our results indicate that M. disstria is actually a composite of regionally adapted populations rather than an extreme generalist. It is unclear, however, what mechanisms might reduce gene flow, allowing such specialization to evolve and persist. We suggest that varying phenology in adult flight times among populations feeding on different hosts could provide at least a partially isolating mechanism, allowing for the evolution of host adaptation.

We examined the effects of fertilization and gypsy moth defoliation of hybrid poplar (Populus ×canadensis Moench 'Eugenei') on ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungal colonization, ECM richness, and ECM composition in the summers of 1997 and 1998. The factorial experiment included two levels of defoliation (defoliated and control) and fertilization (100 kg N·ha–1and control). Gypsy moth (Lymantria dispar L.) populations were manipulated to obtain defoliation in the summer of 1996, 1997, and 1998; fertilization subplots were fertilized with NH4NO3(100 kg N·ha–1) in the spring of these years. There were no significant effects of defoliation on ECM or AM colonization in either year; there was a significant (p ≤ 0.05) decline in AM colonization in fertilized plots in 1997 and a significant interaction between defoliation and fertilization effects on ECM colonization in 1997. In the nondefoliated plots, ECM fungal colonization increased, whereas AM colonization decreased because of fertilization. In the defoliated plots, neither ECM nor AM colonization was affected by fertilization. ECM community composition and richness were unchanged by any treatment. The small and transient effects of defoliation and fertilization on poplar AMs and ECMs demonstrate the tolerance of these early-successional trees to defoliation and their ability to rapidly use high levels of available nitrogen.Key words: Populus, nitrogen, ectomycorrhizas, arbuscular mycorrhizas, ectomycorrhizas, Lymantria dispar (gypsy moth), defoliation.

Foliage quality may decline in deciduous trees following defoliation, thus af- fecting the insect generation responsible for the herbivory (rapid induced resistance, RIR), or future generations (delayed induced resistance, DIR). During outbreaks, trees often suffer partial or complete defoliation for two or more successive years, yet most studies have examined induced resistance following only one season of defoliation, which may not reveal its full impact on herbivores. In a field experiment, 40 trees from each of two clones of trembling aspen, Populus tremuloides, were severely defoliated for one, three, and four years in succession by experimentally manipulating densities of an outbreak folivore, the forest tent caterpillar, Malacosoma disstria. Treatments were applied such that the individual and combined effects of RIR and DIR on the fitness of the forest tent caterpillar could be assessed independently. In field assays, defoliation treatments did not affect larval development time and only marginally affected survival. However, fecundity in both clones was significantly reduced by a single season of defoliation concurrent with the bioassay (effects of RIR), by three consecutive years of defoliation prior to the year of the bioassay (effects of DIR), and by four consecutive years of defoliation (combined effects of RIR and DIR). There were no differences among the three defoliation treatments, indicating that the effects of DIR and RIR combined were not greater than each acting alone. Reductions in fecundity were less than half those observed during natural outbreaks, suggesting that other factors also must contribute to declining fecundity during the collapse of outbreaks. Short-term laboratory bioassays indicated that defoliation effects observed in long-term field assays were not due to changes in relative growth rate (RGR) of second instars or final-instar males, which were unaffected, possibly because of increased relative con- sumption rates (RCR). Defoliation treatments decreased RGR of final-instar females in laboratory bioassays, despite elevated RCR. Both defoliation treatment and aspen clone influenced parasitism by tachinid flies that detect hosts through volatiles released from leaves damaged by caterpillars. Parasitism was highest on trees defoliated concurrently with the larval bioassay. However, there were no differences between trees defoliated prior to the bioassay and control trees, indicating that effects on parasitism were not due to defoliation-induced changes in host quality per se. Thus, there were no additive interactions between DIR and parasitism that would amplify delayed density-dependent effects on population dynamics. Spatial responses of these tach- inids to host density or to current defoliation rather than the defoliation history of the trees may enhance the stabilizing effect of RIR on population dynamics. Conversely, differences in parasitism among clones could contribute to spatial variation in tent caterpillar population density. Neither defoliation effect on host quality nor parasitism was sufficient to slow reproductive rates to levels observed in declining outbreaks in nature, suggesting that single- factor explanations for tent caterpillar population dynamics are unlikely.

The interaction between insect outbreaks and forest health or tree plantation management has been considered rarely from an experimental approach. From 1996 to 1998, we experimentally created a gypsy moth outbreak that defoliated large plots of mature hybrid poplars, Populus ×euramericana, with half of the plots fertilized in a factorial design. The trees were harvested at rotation age in 1999, and we examined the mortality and regeneration of the coppiced (cut at the base) trees in the following growing season. Pre-treatment estimates of tree size strongly predicted the mortality and number of regenerating stems following harvest but not the height of those stems. Defoliation and fertilization each modestly increased tree mortality (10 and 6%, respectively), but the effects were not additive. Only defoliation had strong residual effects on the surviving trees: 25% fewer resprouting stems were produced by previously defoliated trees compared to undefoliated control trees.

Late-summer starch accumulation in fine roots of poplars (Populus x canadensis Moench.) defoliated by gypsy moth (Lymantria dispar L.) lagged behind that in fine roots of undefoliated trees. If starch concentration declines with age, defoliation-induced changes in root system age structure could be partly responsible for this difference. To test this hypothesis, we measured fine-root starch and soluble sugar concentrations in roots of known age from trees in defoliated and undefoliated plots. There was a significant interaction between the effects of defoliation and root type (white, brown, or dead) on fine root soluble sugar concentration because of the high concentration of soluble sugars in white roots from trees in undefoliated plots. Both root starch and soluble sugar concentrations were variable among individuals of each age class. The population frequency distributions for starch and soluble sugar concentrations were both right-skewed, and fit by exponential functions. These data are most consistent with direct defoliation effects on a labile and dynamic pool of carbohydrates in poplar fine roots, rather than indirect defoliation effects on root system age structure.

Large-scale outbreaks of defoliating insects are common in temperate forests. The effects of defoliation on tree physiology are expected to cascade through the entire forest ecosystem, altering carbon, nitrogen, and water fluxes, and subsequently affecting nitrogen cycling and plant-herbivore interactions. If these post-defoliation changes are largely driven by N deficiency, tree root system responses to defoliation should be central to regulating the long-term effects of defoliation; N fertilization should reverse the effects. We examined these phenomena in a 3-year large-scale replicated manipulative field experiment in a hybrid poplar plantation, where we regulated defoliation by gypsy moths as well as nitrogen availability. To our knowledge, this is the first manipulative field experiment at this scale to examine the effects of severe insect defoliation on whole-tree physiology. Defoliation decreased tree growth and increased the rate of top dieback in the stand. Defoliation led to transient declines in carbon allocation to starch in fine roots, trunk, and twigs in the year of heaviest defoliation. Root production and root mortality were unaffected by the heaviest defoliation, but nitrate and ammonium uptake were strongly depressed. N fertilization increased tree growth, but did not alter defoliation effects on starch accumulation or top dieback. Defoliation and fertilization treatments did not interact. In this system, defoliation effects on tree recovery of leaf nitrogen lost to herbivory were primarily driven by effects on nitrogen uptake, rather than effects on root production or mortality.

Summary 1. The fecundity of the forest tent caterpillar varies considerably across its geographic range. Field data indicate that populations in the southern United States (Gulf States) produce nearly twice as many eggs as females from Canada or the Lake States, with little or no difference in the size of adult females. 2. In controlled rearing experiments, female forest tent caterpillar from the southern United States (Louisiana) had much larger clutch sizes than same sized females from northern populations in Michigan or Manitoba, Canada. Increased fecundity in Louisiana females was achieved through a significant reduction in egg size and a concomitant increase in the allocation of resources to egg production. 3. Comparison of 10 forest tent caterpillar populations spanning a 27° latitudinal gradient, validated the results of detailed comparisons among the three populations above by confirming the strong negative correlation between latitude and clutch size. 4. Neonate forest tent caterpillars from Manitoba were significantly larger than larvae from either Michigan or Louisiana. Michigan larvae were intermediate in size. It is postulated that large neonates are advantageous in thermally limiting environments. More than three times as many degree-days are available to Louisiana neonates during the first 2 weeks after hatching. A consistently favourable climate during the vulnerable post-hatching period may have allowed the evolution of larger clutches at the expense of neonate size in southern populations.

Climate change could potentially become one of the most important influences on forest ecosystem function and diversity due to its profound effect on many biotic processes. Additionally, climate change could interact with other anthropogenically driven agents of forest alteration, such as non-native invasive species. Although their arrival is primarily facilitated by global trade and travel, climate and changes to climate have affected and will likely continue to affect rates of invasive species establishment, range expansion, and impact to native ecosystems. In this chapter, we attempt to synthesize broadly the interaction between climate change and non-native insect invasions in temperate forest ecosystems. We highlight four primary effects: changes in distributional ranges, outbreak frequency and intensity, seasonality and voltinism, and trophic interactions. A paucity of data for some processes necessitated the use of exemplar native species in native ranges, and their extrapolation to non-native species. Future studies should give greater attention to the complexity associated with these interacting forces of change in forest ecosystems.

Sub-plots of hybrid poplars were experimentally defoliated using 10 million gypsy moth larvae. Half of the defoliated (and undefoliated control) plots were fertilized to see if this would ameliorate the predicted induction of carbon-based phenolic defenses in the regrowth leaves. In order to bioassay the leaves of the four different treatments, we employed a continuum of genotypes (different hybrids and backcrosses of two different species of tiger swallowtail butterflies) with different abilities to detoxify these allelochemicals. Based on our previous studies with phytochemicals from the Salicaceae plant family, Papilio canadensis was likely to consume and process all Populus spp treatments, whereas P. glaucus predicted to either not consume or else quickly die on all Populus treatment leaves. Hybrid and backcross larvae of these two butterfly species are known to have intermediate levels of esterase detoxication enzymes and would therefore be likely to provide a continuum or at least varying degrees of sensitivity in bioassays for even the most subtle induction responses in the regrowth leaves. This presumption was supported in the feeding and growth studies conducted at different times post-defoliation during the 1997 growing season in Michigan.

Synchrony of egg hatch with budbreak has been proposed as an important component in the population dynamics of many spring feeding forest Lepidoptera. Here, we examine the consequences of phenological asynchrony with the budbreak of trembling aspen (Populus tremu­ loides Michaux) for cohorts of forest tent caterpillar, MalDcosoma disstria Hubner, larvae in north central Alberta, Canada. The timing of eclosure was adjusted through temperature exposure in the laboratory so that pairs of hatching egg bands were placed on trees belonging to a single aspen clone at intervals beginning 2 d before and at 2, 6, 10, and 18 dafter budbreak. On each tree, 1 egg band was protected from predation with a sleeve cage and the other was left unprotected. Larvae from later hatching cohorts required significantly more calendar days and nearly 3 times as many degree-days to complete the 1st instar as did those hatching in synchrony with budbreak. Survi­ vorship oflater hatching cohorts was reduced drastically by invertebrate predation in unprotected groups but no change in overall survival was recorded for protected groups, suggesting that protracted development times caused by declining foliar quality enhanced the success of natural enemies. We hypothesize that a narrow phenological window in host quality after budbreak and its interaction with natural enemies has exerted strong selective pressure on larvae to emerge from eggs as early as possible in the spring and that this window is a potent force in determining the dynamics of low density populations of tent caterpillars.