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The southern pine beetle, Dendroctonus frontalis Zimmermann is an important mortality agent of Pinus in the eastern United States of America where it commonly shares hosts with the black turpentine beetle, Dendroctonus terebrans (Olivier), which infrequently kills trees. Unlike D. frontalis, which must kill its hosts to become established in the bark and reproduce, D. terebrans can occupy living hosts as a parasite. Olfactory mechanisms whereby D. frontalis initially locates hosts have not been demonstrated, whereas D. terebrans responds strongly to host odors. Because D. terebrans produces frontalin, the primary aggregation pheromone component for D. frontalis, and commonly arrives on hosts prior to D. frontalis, it has been hypothesized that D. terebrans pheromone components can mediate D. frontalis location of suitable, living trees. We assessed this possibility with studies of the semiochemical interactions between D. frontalis and D. terebrans. Coupled gas chromatography-electroantennographic detection analyses indicated that D. terebrans produces nine different olfactory stimulants for D. frontalis, nearly all of them known semiochemicals for D. frontalis. A trapping experiment designed to address the potentially confounding influence of lure contamination confirmed that the D. terebrans pheromone component exo-brevicomin enhances attraction of D. frontalis and thus could be an attractive kairomone. In ambulatory bioassays, male D. frontalis were strongly attracted to odors of frass of solitary female and paired D. terebrans, indicating their attraction to the naturally occurring semiochemicals of D. terebrans. Cues from D. terebrans may influence host and mate-finding success of D. frontalis and, thereby, the latter's virulence., (Published by Oxford University Press on behalf of Entomological Society of America 2024.)

Working forests comprise a large proportion of forested landscapes in the southeastern United States and are important to the conservation of bats, which rely on forests for roosting and foraging. While relationships between bat ecology and forest management are well studied during summer, winter bat ecology remains understudied. Hence, we aimed to identify the diet composition of overwintering bats, compare the composition of prey consumed by bat species, and determine the potential role of forest bats as pest controllers in working forest landscapes of the southeastern U.S. Coastal Plain. During January to March 2021-2022, we captured 264 bats of eight species. We used DNA metabarcoding to obtain diet composition from 126 individuals of seven bat species identifying 22 orders and 174 families of arthropod prey. Although Coleoptera, Diptera, and Lepidoptera were the most consumed orders, we found that bats had a generalist diet but with significant differences among some species. We also documented the consumption of multiple insect pests (e.g., Rhyacionia frustrana) and disease vectors (e.g., Culex spp). Our results provide important information regarding the winter diet of bats in the southeastern U.S. Coastal Plain and their potential role in controlling economically relevant pest species and disease vectors., (© 2024. The Author(s).)

Manganese (Mn) deficiency is a widespread occurrence across different landscapes, including agricultural systems and managed forests, and causes interruptions in the normal metabolic functioning of plants. The microelement is well-characterized for its role in the oxygen-evolving complex in photosystem II and maintenance of photosynthetic structures. Mn is also required for a variety of enzymatic reactions in secondary metabolism, which play a crucial role in defense strategies for trees. Despite the strong relationship between Mn availability and the biosynthesis of defense-related compounds, there are few studies addressing how Mn deficiency can impact tree defense mechanisms and the ensuing ecological patterns and processes. Understanding this relationship and highlighting the potentially deleterious effects of Mn deficiency in trees can also inform silvicultural and management decisions to build more robust forests. In this review, we address this relationship, focusing on forest trees. We describe Mn availability in forest soils, characterize the known impacts of Mn deficiency in plant susceptibility, and discuss the relationship between Mn and defense-related compounds by secondary metabolite class. In our review, we find several lines of evidence that low Mn availability is linked with lowered or altered secondary metabolite activity. Additionally, we compile documented instances where Mn limitation has altered the defense capabilities of the host plant and propose potential ecological repercussions when studies are not available. Ultimately, this review aims to highlight the importance of untangling the effects of Mn limitation on the ecophysiology of plants, with a focus on forest trees in both managed and natural stands., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Anthropogenic contamination from coal-fired power plants and nuclear reactors is a pervasive issue impacting ecosystems across the globe. As a result, it is critical that studies continue to assess the accumulation and effects of trace elements and radionuclides in a diversity of biota. In particular, bioindicator species are a powerful tool for risk assessment of chemically contaminated habitats. Using inductively coupled plasma mass spectrometry (ICP-MS) and auto-gamma counting, we analyzed trace element and radiocesium contaminant concentrations in Scarabaeidae and Silphidae beetles (Order: Coleoptera), important taxa in decomposition and nutrient cycling, at contaminated and reference sites on the Savannah River Site, South Carolina, U.S. Our results revealed variability in trace element concentrations between Scarabaeidae and Silphidae beetles at uncontaminated and contaminated sites. Compared to Scarabaeidae, Silphidae had higher levels of chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn). Unexpectedly, concentrations of Cr, Cu, and Ni were higher in both taxa at the uncontaminated sites. Scarabaeidae and Silphidae beetles at the coal combustion waste site consistently had high concentrations of arsenic (As), and Scarabaeidae had high concentrations of selenium (Se). Of the 50 beetles analyzed for radiocesium levels, two had elevated radioactivity concentrations, both of which were from a site contaminated with radionuclides. Our results suggest carrion beetles may be particularly sensitive to bioaccumulation of contaminants due to their trophic position and role in decomposition, and thus are useful sentinels of trace element and radionuclide contamination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Society is confronted by interconnected threats to ecological sustainability. Among these is the devastation of forests by destructive non-native pathogens and insects introduced through global trade, leading to the loss of critical ecosystem services and a global forest health crisis. We argue that the forest health crisis is a public-good social dilemma and propose a response framework that incorporates principles of collective action. This framework enables scientists to better engage policymakers and empowers the public to advocate for proactive biosecurity and forest health management. Collective action in forest health features broadly inclusive stakeholder engagement to build trust and set goals; accountability for destructive pest introductions; pooled support for weakest-link partners; and inclusion of intrinsic and nonmarket values of forest ecosystems in risk assessment. We provide short-term and longer-term measures that incorporate the above principles to shift the societal and ecological forest health paradigm to a more resilient state.

The Nantucket pine tip moth (NPTM) (Rhyacionia frustrana Comstock) is a native, regeneration pest of young loblolly pines (Pinus taeda L.), causing shoot dieback, tree deformity, and growth and volume declines. Soil applications of systemic insecticides may be an effective strategy to suppress NPTM populations. The study objective was to assess the efficacy of four systemic insecticide treatments (chlorantraniliprole, dinotefuran, fipronil, and imidacloprid) for two growing seasons in outplanted bareroot and containerized seedling trials. Response variables included NPTM infestation rates, along with tree height, groundline diameter, volume index, and stem form. Infestation rates significantly decreased for each systemic insecticide treatment during the first year compared to controls, although dinotefuran and imidacloprid provided season-long control in one trial. Chlorantraniliprole reduced NPTM infestation rates for two growing seasons in both trials. While imidacloprid treatments did not alter growth metrics except for one comparison, fipronil and dinotefuran treatments improved several growth metrics. Chlorantraniliprole consistently improved growth metrics throughout the study., (© The Author(s) 2023. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Climate change models often assume similar responses to temperatures across the range of a species, but local adaptation or phenotypic plasticity can lead plants and animals to respond differently to temperature in different parts of their range. To date, there have been few tests of this assumption at the scale of continents, so it is unclear if this is a large-scale problem. Here, we examined the assumption that insect taxa show similar responses to temperature at 96 sites in grassy habitats across North America. We sampled insects with Malaise traps during 2019-2021 (N = 1041 samples) and examined the biomass of insects in relation to temperature and time of season. Our samples mostly contained Diptera (33%), Lepidoptera (19%), Hymenoptera (18%), and Coleoptera (10%). We found strong regional differences in the phenology of insects and their response to temperature, even within the same taxonomic group, habitat type, and time of season. For example, the biomass of nematoceran flies increased across the season in the central part of the continent, but it only showed a small increase in the Northeast and a seasonal decline in the Southeast and West. At a smaller scale, insect biomass at different traps operating on the same days was correlated up to ~75 km apart. Large-scale geographic and phenological variation in insect biomass and abundance has not been studied well, and it is a major source of controversy in previous analyses of insect declines that have aggregated studies from different locations and time periods. Our study illustrates that large-scale predictions about changes in insect populations, and their causes, will need to incorporate regional and taxonomic differences in the response to temperature., (© 2023 The Authors. Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.)

Natural disasters interact to affect the resilience and prosperity of communities and disproportionately affect low income families and communities of colour. However, due to lack of a common theoretical framework, these are rarely quantified. Observing severe weather events (e.g. hurricanes and tornadoes) and epidemics (e.g. COVID-19) unfolding in southeastern US communities led us to conjecture that interactions among catastrophic disturbances might be much more considerable than previously recognized. For instance, hurricane evacuations increase human aggregation, a factor that affects the transmission of acute infections like SARS-CoV-2. Similarly, weather damage to health infrastructure can reduce a community's ability to provide services to people who are ill. As globalization and human population and movement continue to increase and weather events are becoming more intense, such complex interactions are expected to magnify and significantly impact environmental and human health., (© 2023 The Authors. Ecology Letters published by John Wiley & Sons Ltd.)

Some introduced species cause severe damage, although the majority have little impact. Robust predictions of which species are most likely to cause substantial impacts could focus efforts to mitigate those impacts or prevent certain invasions entirely. Introduced herbivorous insects can reduce crop yield, fundamentally alter natural and managed forest ecosystems, and are unique among invasive species in that they require certain host plants to succeed. Recent studies have demonstrated that understanding the evolutionary history of introduced herbivores and their host plants can provide robust predictions of impact. Specifically, divergence times between hosts in the native and introduced ranges of a nonnative insect can be used to predict the potential impact of the insect should it establish in a novel ecosystem. However, divergence time estimates vary among published phylogenetic datasets, making it crucial to understand if and how the choice of phylogeny affects prediction of impact. Here, we tested the robustness of impact prediction to variation in host phylogeny by using insects that feed on conifers and predicting the likelihood of high impact using four different published phylogenies. Our analyses ranked 62 insects that are not established in North America and 47 North American conifer species according to overall risk and vulnerability, respectively. We found that results were robust to the choice of phylogeny. Although published vascular plant phylogenies continue to be refined, our analysis indicates that those differences are not substantial enough to alter the predictions of invader impact. Our results can assist in focusing biosecurity programs for conifer pests and can be more generally applied to nonnative insects and their potential hosts by prioritizing surveillance for those insects most likely to be damaging invaders., (© 2022 The Ecological Society of America. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Disturbances alter biodiversity via their specific characteristics, including severity and extent in the landscape, which act at different temporal and spatial scales. Biodiversity response to disturbance also depends on the community characteristics and habitat requirements of species. Untangling the mechanistic interplay of these factors has guided disturbance ecology for decades, generating mixed scientific evidence of biodiversity responses to disturbance. Understanding the impact of natural disturbances on biodiversity is increasingly important due to human-induced changes in natural disturbance regimes. In many areas, major natural forest disturbances, such as wildfires, windstorms, and insect outbreaks, are becoming more frequent, intense, severe, and widespread due to climate change and land-use change. Conversely, the suppression of natural disturbances threatens disturbance-dependent biota. Using a meta-analytic approach, we analysed a global data set (with most sampling concentrated in temperate and boreal secondary forests) of species assemblages of 26 taxonomic groups, including plants, animals, and fungi collected from forests affected by wildfires, windstorms, and insect outbreaks. The overall effect of natural disturbances on α-diversity did not differ significantly from zero, but some taxonomic groups responded positively to disturbance, while others tended to respond negatively. Disturbance was beneficial for taxonomic groups preferring conditions associated with open canopies (e.g. hymenopterans and hoverflies), whereas ground-dwelling groups and/or groups typically associated with shady conditions (e.g. epigeic lichens and mycorrhizal fungi) were more likely to be negatively impacted by disturbance. Across all taxonomic groups, the highest α-diversity in disturbed forest patches occurred under moderate disturbance severity, i.e. with approximately 55% of trees killed by disturbance. We further extended our meta-analysis by applying a unified diversity concept based on Hill numbers to estimate α-diversity changes in different taxonomic groups across a gradient of disturbance severity measured at the stand scale and incorporating other disturbance features. We found that disturbance severity negatively affected diversity for Hill number q = 0 but not for q = 1 and q = 2, indicating that diversity-disturbance relationships are shaped by species relative abundances. Our synthesis of α-diversity was extended by a synthesis of disturbance-induced change in species assemblages, and revealed that disturbance changes the β-diversity of multiple taxonomic groups, including some groups that were not affected at the α-diversity level (birds and woody plants). Finally, we used mixed rarefaction/extrapolation to estimate biodiversity change as a function of the proportion of forests that were disturbed, i.e. the disturbance extent measured at the landscape scale. The comparison of intact and naturally disturbed forests revealed that both types of forests provide habitat for unique species assemblages, whereas species diversity in the mixture of disturbed and undisturbed forests peaked at intermediate values of disturbance extent in the simulated landscape. Hence, the relationship between α-diversity and disturbance severity in disturbed forest stands was strikingly similar to the relationship between species richness and disturbance extent in a landscape consisting of both disturbed and undisturbed forest habitats. This result suggests that both moderate disturbance severity and moderate disturbance extent support the highest levels of biodiversity in contemporary forest landscapes., (© 2022 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.)

Emerald ash borer ( Agrilus planipennis ; EAB) has devastated populations of ash ( Fraxinus spp.) trees in dozens of U.S. states and Canada over the past few decades. The continued survival of scattered ash trees known as "lingering ash" in heavily infested natural stands, however, offers evidence of genetic resistance or tolerance to EAB. These surviving or "lingering" ash individuals may form the basis for reforestation programs in EAB-impacted areas, and clonal mass-propagation of these genotypes can help accelerate these efforts. Between 2013 and 2018, we initiated embryogenic cultures by culturing immature zygotic embryos from open-pollinated (OP) seeds collected from several surviving white ash and green ash trees in Michigan and Pennsylvania. In addition, in 2018, we initiated cultures from crosses made between lingering green ash parents from the USDA Forest Service ash breeding program in Ohio. Somatic embryos were produced by growing cultures in liquid suspension, followed by fractionation and plating on semisolid medium to produce developmentally synchronous populations of somatic embryos. Somatic embryo germination and conversion were enhanced by a combination of pre-germination cold treatment and inclusion of activated charcoal and gibberellic acid in the germination medium. Ash somatic seedlings derived from OP explants grew rapidly following transfer to potting mix and somatic seedlings representing nine ash clones were acclimatized, grown in the greenhouse and planted in a preliminary field test, along with EAB-resistant Manchurian ash ( F. mandshurica ) and EAB-susceptible control seedlings. Somatic seedlings have now been produced from cultures that originated from seeds derived from the progeny of lingering green ash parents and an ex vitro germination protocol has shown some promise for accelerating early somatic seedling growth. Results of this research could provide the basis for scaled-up production of EAB-resistant ash varieties for seed orchard production for forest restoration and cultivar development for urban tree restoration., Competing Interests: Conflict of interestThe authors declare that they have no conflicts of interest., (© The Author(s), under exclusive licence to Springer Nature B.V. 2022.)

1) Many wild bee species interact with soil either as a nesting substrate or material. These soil interactions create a risk of exposure to agrochemicals such as imidacloprid or other neonicotinoid pesticides that can persist in soil for months after application. At the landscape level, concentrations of imidacloprid residue in soil are limited to the immediate treatment area, and thus risks to soil-interacting bees could be low if they avoid contaminated soils. 2) We utilized Osmia lignaria (Say), a solitary cavity nesting bee which collects mud to partition and seal nests, and conducted two laboratory experiments to test whether nesting females select or avoid soils containing various levels of imidacloprid residue. For the first experiment, we assessed behavioral responses of females to treated soil utilizing a choice arena and pairing various choices of soil with imidacloprid residues ranging between 0 and 780 ppb. For the second experiment, we developed a laboratory assay to assess soil selection of actively nesting O. lignaria, by providing choices of contaminated soil between 0 and 100 ppb and 0 and 1,000 ppb to nesting females. 3) We found no evidence that O. lignaria females avoided any level of imidacloprid contamination, even at the highest residue level (1,000 ppb) in both the experiments, which may have implications for risk. The in situ nesting methodology developed in this study has future applications for research on soil or pollen preferences of cavity nesting Osmia species, and potential for breeding of O. lignaria in laboratory., (© The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Energy production systems such as nuclear reactors and coal-burning power plants produce a multitude of waste contaminants including radionuclides, trace elements, and heavy metals. Among invertebrates, much of the effort to understand the impact of these contaminants has focused in aquatic environments, while relatively less attention has been on terrestrial communities. We investigated the effects of trace element and radionuclide contamination on assemblages of beetles that are drawn to vertebrate carrion. Samples were collected from riparian sites at the Savannah River Site in South Carolina to compare trap catches (i.e., measure of relative abundance) of beetles and species diversity along a habitat gradient (0-300 m) away from an aquatic habitat and between uncontaminated and contaminated sites. We collected 17,800 carrion-associated beetles representing 112 species in nine families, which were classified as either scavenger or predatory beetles. Beetle catches and species diversity were generally higher at contaminated than uncontaminated sites. These trends were likely driven by scavenger species, which showed similar patterns between sites, whereas patterns of catches and species diversity were variable between sites for predatory beetles. Species compositions of contaminated and uncontaminated sites were generally distinct, however habitat edges appeared to substantially affect beetle assemblages. Overall, our study suggests carrion beetle assemblages are sensitive to edge effects and may exhibit variable responses to the presence of anthropogenic contaminants or disturbances associated with energy production systems. Such results reflect the inherent variability among individual beetle species, populations, and communities to local environmental conditions, and underscores the need for multi-taxa approach in environmental impact assessments., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A long-standing goal of invasion biology is to identify factors driving highly variable impacts of non-native species. Although hypotheses exist that emphasize the role of evolutionary history (e.g., enemy release hypothesis & defense-free space hypothesis), predicting the impact of non-native herbivorous insects has eluded scientists for over a century.Using a census of all 58 non-native conifer-specialist insects in North America, we quantified the contribution of over 25 factors that could affect the impact they have on their novel hosts, including insect traits (fecundity, voltinism, native range, etc.), host traits (shade tolerance, growth rate, wood density, etc.), and evolutionary relationships (between native and novel hosts and insects).We discovered that divergence times between native and novel hosts, the shade and drought tolerance of the novel host, and the presence of a coevolved congener on a shared host, were more predictive of impact than the traits of the invading insect. These factors built upon each other to strengthen our ability to predict the risk of a non-native insect becoming invasive. This research is the first to empirically support historically assumed hypotheses about the importance of evolutionary history as a major driver of impact of non-native herbivorous insects.Our novel, integrated model predicts whether a non-native insect not yet present in North America will have a one in 6.5 to a one in 2,858 chance of causing widespread mortality of a conifer species if established ( R 2  = 0.91) Synthesis and applications . With this advancement, the risk to other conifer host species and regions can be assessed, and regulatory and pest management efforts can be more efficiently prioritized., Competing Interests: The authors declare no conflict of interest., (© 2019 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

The black turpentine beetle, Dendroctonus terebrans Olivier is the largest pine-infesting bark beetle native to the southern and eastern United States. It generally reproduces in fresh stumps and bases of trees weakened or killed by other biotic or abiotic agents, although it can also infest and sometimes kills apparently healthy trees. Its numbers can build when large amounts of host material become available (typically through a disturbance), and black turpentine beetle-caused mortality at a local scale can become considerable. Here, we provide a complete review of the literature on this species, including its taxonomy, host, life history, chemical ecology, arthropod and microbial associates, and management options. We also provide original data on numbers of instars, acoustic signals, and pheromone chirality in this species. Our survey of the existing literature revealed that key biological characteristics of black turpentine beetles are known, but interactions with closely associated organisms, economic and ecological impacts, and improvements to monitoring and management practices have been only partially investigated., (Published by Oxford University Press on behalf of Entomological Society of America 2019.)

ederal policies related to forestry and forest health (specifically, insects and diseases) have the potential to affect management practices, terms of international and interstate trade, and long-term sustainability and conservation. Our objectives were to review existing federal policies, the role of federal agencies in managing forest health, and guidance for future policy efforts. Since the 1940s, various federal policies relevant to forest health have been established, and several US Department of Agriculture (USDA) agencies have been empowered to assist with prevention, quarantine, detection, management, and control of insects and diseases. Overall, our review showed that relatively few national policies directly address forest health as a stand-alone objective, as most of them are embedded within forestry bills. Federal funding for forest health issues and the number of personnel dedicated to such issues have declined dramatically for some agencies. Concomitantly, native species continue to gain pestiferous status while non-native species continue to establish and cause impacts in the US. To enhance our ability and capacity to deal with current and future threats, concerted efforts are needed to advocate for both resources and stand-alone policy tools that take seriously the complexity of emerging sustainability challenges in both private and public forestlands.