Partial brood loss in Dryobates borealis (Red-cockaded Woodpecker), a federally threatened cooperative breeder in the USA, was not associated with increases in population density. Across three populations-Sandhills, North Carolina; Marine Corps Base Camp Lejeune, North Carolina; and Eglin Air Force Base, Florida-we documented no support for density-dependent effects on either early or late partial brood loss. Using long-term nest monitoring data, we evaluated multiple metrics of group size and group density in relation to brood loss at early (egg-to-nestling up to 6-10 days when banded) and late (banding-to-fledgling up to 38-40 days) stages. Reproductive outcomes did not vary with density within populations, indicating that the recent rise in partial brood loss, particularly late in the nestling period, was not driven by increasing density. While both density and partial brood loss have increased over time, these trends appear to be decoupled, highlighting the need to investigate other potential drivers of partial brood loss. Cooperative breeding can buffer reproductive output from density-related pressures through shared parental care, but as densities increase due to conservation-driven population recovery, cooperative breeders may face new or shifting constraints. Variation in reproductive outcomes may be more closely tied to site-specific factors or density-independent pressures such as weather, predation, or habitat quality. As D. borealis populations continue to grow under ongoing recovery efforts, understanding the mechanisms behind partial brood loss remains critical for refining conservation strategies. Our results add to growing evidence that density-dependent effects on reproduction are not universal; increasing density, though a conservation success, does not necessarily lead to reduced productivity or increased brood loss. We studied whether increasing population density affects partial brood loss (when some, but not all, eggs or chicks fail to survive) in the federally threatened, cooperatively breeding Dryobates borealis (Red-cockaded Woodpecker). This species has been recovering due to conservation efforts, leading to increased population densities in parts of its range. We used long-term data from three sites in the southeastern United States to determine if greater density led to more partial brood loss. We documented no evidence that density was linked to either early or late partial brood loss at any of the three sites, though we did show evidence that late partial brood loss may be increasing. These results indicate that other factors, including weather or habitat quality, may be more important than density in limiting this component of reproduction. La p & eacute;rdida parcial de la nidada en Dryobates borealis, un reproductor cooperativo amenazado a nivel federal en Estados Unidos, no estuvo asociada con aumentos en la densidad poblacional. En tres poblaciones-Sandhills, Carolina del Norte; Base del Cuerpo de Marines Camp Lejeune, Carolina del Norte; y Base de la Fuerza A & eacute;rea de Eglin, Florida-no encontramos evidencia que respalde efectos dependientes de la densidad sobre la p & eacute;rdida parcial temprana o tard & iacute;a de la nidada. Utilizando datos de monitoreo de nidos a largo plazo, evaluamos m & uacute;ltiples m & eacute;tricas del tama & ntilde;o del grupo y de la densidad grupal en relaci & oacute;n con la p & eacute;rdida de la nidada en etapas tempranas (desde huevo a pich & oacute;n hasta 6-10 d & iacute;as al momento del anillado) y tard & iacute;as (desde el anillado hasta el volant & oacute;n, hasta 38-40 d & iacute;as). Los resultados reproductivos no variaron con la densidad dentro de las poblaciones, lo que indica que el aumento reciente de la p & eacute;rdida parcial de la nidada, particularmente hacia el final del per & iacute;odo de pichones, no estuvo impulsado por un incremento en la densidad. Si bien tanto la densidad como la p & eacute;rdida parcial de la nidada han aumentado con el tiempo, estas tendencias parecen estar desacopladas, lo que pone de relieve la necesidad de investigar otros posibles factores causales de la p & eacute;rdida parcial de la nidada. La reproducci & oacute;n cooperativa puede amortiguar el rendimiento reproductivo frente a presiones relacionadas con la densidad mediante el cuidado parental compartido, pero a medida que las densidades aumentan debido a la recuperaci & oacute;n poblacional impulsada por la conservaci & oacute;n, los reproductores cooperativos pueden enfrentar restricciones nuevas o cambiantes. La variaci & oacute;n en los resultados reproductivos puede estar m & aacute;s estrechamente vinculada a factores espec & iacute;ficos del sitio o a presiones independientes de la densidad, como el clima, la depredaci & oacute;n o la calidad del h & aacute;bitat. A medida que las poblaciones de D. borealis contin & uacute;an creciendo bajo los esfuerzos de recuperaci & oacute;n en curso, comprender los mecanismos detr & aacute;s de la p & eacute;rdida parcial de la nidada sigue siendo fundamental para afinar las estrategias de conservaci & oacute;n. Nuestros resultados se suman a la evidencia creciente de que los efectos dependientes de la densidad sobre la reproducci & oacute;n no son universales; el aumento de la densidad, aunque sea un & eacute;xito de conservaci & oacute;n, no conduce necesariamente a una menor productividad ni a una mayor p & eacute;rdida de nidadas.

Understanding the seasonal phenology of an insect pest in a specific region on a specific host is fundamental to the timing of management actions. The elongate hemlock scale, Fiorinia externa Ferris (Hemiptera: Diaspididae), is an invasive insect from Japan known to infest various conifer hosts in its invasive range in eastern North America. The phenology of the scale has been studied on hemlock (Tsuga spp.) hosts in its native range and portions of its invasive range in the northeastern and mid-Atlantic regions of the United States; similar studies are lacking for the southeastern region. In the Southern Appalachians, this scale poses a significant management and regulatory challenge for Fraser fir (Abies fraseri [Pursh] Poir.,) Christmas tree production. The objective of this study was to examine the seasonal phenology of the scale in the western North Carolina production region. Biweekly samples were collected from Fraser fir at three sites over 2 years and analyzed for abundance of each life stage. We found all life stages present at all locations throughout the year. Large variability in egg abundance was observed across 2 years. There was little variability in the abundance of life stages between sampling locations. Substantially more scale eggs, crawlers, 2nd instar nymphs and adult females were observed on the 2 most recent years' needles as opposed to older needles. These findings can help optimize the timing of management practices to control the elongate hemlock scale more effectively.

Most canopy insect research takes place in tropical forests, where communities are highly vertically stratified. However, temperate forest canopies also provide critical resources to many species and are under intense pressure from global change drivers. The relative lack of knowledge regarding temperate canopy insect ecology impedes our forest management and conservation decisions such that we may be losing temperate canopy biodiversity before we know it exists. We directly compared ant diversity and community composition on the ground and in the tree canopy of North American temperate deciduous forests for the first time. We also evaluated two canopy sampling methods-baits and hand collections. We collected 34 ant species from 102 trees across seven sites. Ant diversity was greater on the ground than in the canopy, and species turnover created distinct communities across vertical strata. Only 12% of species were exclusively arboreal, but 47% were collected in both strata, indicating the canopy is an important resource for temperate ants, even if they are not restricted there. Baiting and hand-collecting recovered similar species richness, but whether baits captured a subset of hand-collected species or a unique assemblage was site-dependent. Nevertheless, we suggest that these methods are most effective in conjunction. Hand collection allowed us to document arboreal nests of 10 species, including the invasive needle ant, Brachyponera chinensis, which was previously thought to be strictly terrestrial. Our results emphasise the importance of including the canopy in temperate forest ecology and conservation assessments.

The elongate hemlock scale (Fiorinia externa Ferris; Hemiptera: Diaspididae) is an invasive insect that originated in Japan and was first detected in North America in Queens NY in 1908. It has since become a significant post-harvest pest of Fraser fir (Abies fraseri [Pursh] Poir.), posing regulatory problems for the North Carolina Christmas tree industry which produces trees that are sold and moved across the country. Observations by specialists suggest that crawlers, one of two mobile stages of the insect, can emerge from eggs on host material for an extended period, potentially spreading this scale to new areas. However, research into crawler emergence under variable conditions, as well as the duration harvested Fraser fir can sustain live egg-producing adult female elongate hemlock scale (and thus prolong crawler emergence) is lacking. Therefore, we evaluated these insects' post-harvest activity on cut Fraser fir. In our first study, we evaluated weekly crawler emergence from Fraser fir trees and branches between two post-harvest treatments (baled and unbaled) under constant conditions for 7 wk. The second experiment aimed to simulate a Christmas tree's post-harvest lifecycle, over 13 wk, from lot (outdoor) to home (indoor) to discarding (outdoor). Our results show that crawlers continue to emerge from post-harvest Fraser fir for up to 40 and 90 d in our seven- and 13-wk studies, respectively. Moreover, we found live females with eggs present for up to 50 d post-harvest. These findings highlight the potential risk of introducing this scale to new areas via Fraser fir Christmas tree shipments.

PREMISE:Understanding the factors that limit reproductive success is a key component of plant biology. Carnivorous plants rely on insects as both nutrient sources and pollinators, providing a unique system for studying the effects of both resource and pollen limitation on plant reproduction. METHODS:We conducted a field experiment using wild-growing Dionaea muscipula J. Ellis (Droseraceae) in which we manipulated prey and pollen in a factorial design and measured flower production, number of fruits, and number of seeds. Because understanding reproduction requires knowledge of a plant species' reproductive and pollination biology, we also examined the pollination system, per-visit pollinator effectiveness, and pollen-ovule (P/O) ratio of D. muscipula. RESULTS:Plants that received supplemental prey produced more flowers than control plants. They also had a higher overall fitness estimate (number of flowers × fruit set (total fruits/total flowers) × seeds per fruit), although this benefit was significant only when prey supplementation occurred in the previous growing season. Neither pollen supplementation nor the interaction between pollen and prey supplementation significantly affected overall plant fitness. CONCLUSIONS:This study reinforces the reliance of D. muscipula on adequate prey capture for flower, fruit, and seed production and a mobile pollen vector for reproduction, indicating the importance of considering insects as part of an effective conservation management plan for this species.

ABSTRACT Extreme high temperatures associated with climate change can affect species directly, and indirectly through temperature-mediated species interactions. In most host–parasitoid systems, parasitization inevitably kills the host, but differences in heat tolerance between host and parasitoid, and between different hosts, may alter their interactions. Here, we explored the effects of extreme high temperatures on the ecological outcomes – including, in some rare cases, escape from the developmental disruption of parasitism – of the parasitoid wasp, Cotesia congregata, and two co-occurring congeneric larval hosts, Manduca sexta and M. quinquemaculata. Both host species had higher thermal tolerance than C. congregata, resulting in a thermal mismatch characterized by parasitoid (but not host) mortality under extreme high temperatures. Despite parasitoid death at high temperatures, hosts typically remain developmentally disrupted from parasitism. However, high temperatures resulted in a partial developmental recovery from parasitism (reaching the wandering stage at the end of host larval development) in some host individuals, with a significantly higher frequency of this partial developmental recovery in M. quinquemaculata than in M. sexta. Hosts species also differed in their growth and development in the absence of parasitoids, with M. quinquemaculata developing faster and larger at high temperatures relative to M. sexta. Our results demonstrate that co-occurring congeneric species, despite shared environments and phylogenetic histories, can vary in their responses to temperature, parasitism and their interaction, resulting in altered ecological outcomes.

Invertebrates, especially those dependent on woody debris for a portion of their life cycle, may be greatly impacted by the amount of downed wood retained following timber harvests. To document relationships between invertebrates and logging residues, we sampled invertebrates with pitfall traps placed near or far from woody debris in 10 recently (2013–2015) harvested sites in western North Carolina with varying levels of woody debris retention. We measured the groundcover and microclimate at each trap and estimated site-level woody debris volume. We modeled predictors (e.g., site-level woody debris volume, percent woody debris cover at the trap site, site type) of captures of spiders (Araneae), harvestmen (Opiliones), centipedes/millipedes (Chilopoda/Diplopoda), ground beetles (Carabidae), rove beetles (Staphylinidae), other beetles, ants (Formicidae), grasshoppers (Acrididae/Tetrigidae), crickets (Gryllidae), and cave crickets (Rhaphidophoridae). In addition, we modeled ant occurrence at a finer taxonomic resolution, including red imported fire ants (Solenopsis invicta Buren) and 13 other genera/species. Forest type, whether hardwood or white pine (Pinus strobus L.) overstory preharvest, was a predictor of invertebrate response for 21 of 24 taxonomic analyses. Invertebrate captures or the occurrence probability of ants increased with increasing site-level woody debris volume for 13 of the 24 taxa examined and increased with increasing coarse woody debris (CWD; diameter ≥ 10 cm) cover at the trap level for seven of 24 taxa examined. Our results indicate that woody debris in harvested sites is important for the conservation of a majority of the taxa we studied, which is likely because of the unique microclimate offered near/under woody debris. Stand-scale factors typically were more important predictors of invertebrate response than trap-level cover of woody debris. We recommend implementing sustainability strategies (e.g., Biomass Harvesting Guidelines) to retain woody debris scattered across harvested sites to aid in the conservation of invertebrates.

1. Dead arthropods, entrapped by trichomes on plant surfaces, are an underappreciated form of plant‐provided food. Specialist predatory arthropods able to manoeuvre on plants covered in trichomes facultatively scavenge on the alternative food resource, increasing their abundance and reducing plant damage by herbivores.2. This protective mutualism dependent on arthropod carrion has been demonstrated in several plant species, but the mechanisms driving the increase in predator abundance have not been identified. Through a series of greenhouse and laboratory experiments, the effect of arthropod carrion on predator behaviour was assessed.3. The predatorJalysus wickhamipreferredNicotiana tabacumplants augmented with arthropod carrion, spending significantly more time and laying more eggs on those plants than plants without arthropod carrion.4. Under lowJ. wickhamidensities, arthropod carrion did not reduce egg cannibalism by adults. Under high densities, egg cannibalism byJ. wickhamiadults was reduced in the presence of arthropod carrion, but cannibalism by fifth instars was not.5. Arthropod carrion may be utilised by a wide range of predatory arthropods that facultatively scavenge, and this research demonstrates its potential for influencing arthropod–plant and arthropod–arthropod interactions.

Jalysus wickhami Van Duzee is the most abundant predator in North Carolina flue-cured tobacco production but information on the effect of contemporary pest management practices and interactions with other arthropods is lacking. We measured the effect of systemic imidacloprid on J. wickhami in field experiments during 2015 and 2016 by surveying its abundance, the abundance of its prey; the pests Heliothis virescens (Fabricus), Manduca sexta L., and Manduca quinquemaculata (Haworth, 1803); and other predatory arthropods in the agro-ecosystem. Systemic imidacloprid applications did not reduce J. wickhami abundance nor increase the abundance of H. virescens, M. sexta, and M. quinquemaculata, indicating natural control was not affected. J. wickhami abundance was positively correlated with the abundance of prey and predators from another feeding guild, suggesting species interactions have significant implications for the predators.

Prescribed burning is a common silvicultural practice used in the management of longleaf pine (Pinus palustris Mill., Pinales: Pinaceae) savannas to reduce hardwood encroachment and ground cover and to maintain biodiversity. We investigated the response of the native bee community (Hymenoptera: Apoidea: Anthophila) in the Sandhills of North Carolina to prescribed burning on a 3-yr rotation over two consecutive years (2012 and 2013). We deployed bee bowl traps in sites that had been burned the year of sampling, 1 yr before, 2 yr before, and in unburned controls. In total, 2,276 bees of 109 species were captured. Bee abundance declined with time since fire, with 2.3 times more bees captured in the most recently burned sites than in unburned controls. Bee diversity also declined with time since fire, with 2.1 times more species captured in the most recently burned sites than in controls. Bee community composition also responded to fire; we present evidence that this response was mediated in part by the effect of fire on the amount of bare ground and canopy cover. Bees nesting aboveground were unaffected by fire, contrary to our expectation that fire would destroy the wood and stems in which these species nest. Our results indicate that prescribed burning is a silvicultural practice consistent with pollinator conservation in longleaf pine ecosystems of the North Carolina sandhills.

Helicoverpa zea Boddie is a common economic pest of cotton (Gossypium hirsutum L.), including transgenic cotton varieties that express Bacillus thuringiensis (Bt). Helicoverpa zea oviposition is similar in Bt and non-Bt cotton, but behavior of H. zea larvae can be different in the presence of Bt, with neonates moving away from terminals faster in single-toxin Bt than non-Bt cotton or avoiding Bt-treated diet in the lab. We quantified H. zea oviposition and larval distribution on structures within cotton plants in small plot experiments of Cry1Ac + Cry1F cotton for 2 yr under different irrigation and nitrogen treatments. More eggs were oviposited on plants receiving nitrogen application during 2016 and on leaves in the top section of irrigated plants during 2017, but other treatment effects on eggs or larvae were minimal. Helicoverpa zea eggs were most common on leaves in the top third of plants at position zero and middle section of cotton plants throughout the season, but some oviposition occurred on fruiting structures as well. First and second instars were more common on squares in the top section of plants during 2016 and bolls in the middle and lower sections during 2017 due to oviposition lower in the canopy during 2017. During both years, third through fifth instars were more common on bolls in the middle and lower section of plants closer to the main stem. These findings have resistance management implications as extended larval feeding on bolls could optimize nutrition, decrease Bt susceptibility, and potentially influence behavioral resistance.

Maximizing plant defensive strategies is integral to effective integrated pest management. Direct defenses, in the form of chemical and morphological components that inhibit pest damage, underlie host plant resistance, while indirect defenses including food provisioning and semiochemical production, improve biological control. Interactions between the two defensive strategies may be disruptive, complementary, or synergistic and are an important consideration for effective pest management programs. Glandular trichomes are plant structures that inhibit or entrap arthropods, protecting plants against herbivores, potentially at the cost of reducing natural enemy efficacy. Glandular trichomes may also contribute to indirect defense, as predatory arthropods adapted to "sticky" surfaces scavenge on entrapped arthropods. Scavenging increases predator abundance and reduces plant damage; this protective mutualism has been demonstrated with multiple sticky wild flowers but has not been assessed in an economically important plant, such as tobacco. We augmented dead arthropods (carrion) on tobacco plants grown under conditions similar to commercial production and assessed tri-trophic interactions. Carrion augmentation increased predator abundance, reduced damage to reproductive structures, and increased leaf yield, but did not reduce pest densities. We determined that systemic insecticide use did not affect carrion entrapment on tobacco plants. Review of the literature revealed that a variety of economically important plants entrap arthropods on their surfaces, indicating this mutualism has potential for development into a conservation biological control tactic.

In some Bt cotton (Gossypium hirsutum L.) varieties, bollworm (Helicoverpa zea Boddie) larval behavior differs from non-Bt varieties. Laboratory assays indicate bollworm larvae can detect Bt proteins, which may cause behavioral differences. Plant stress from factors including fertility and water availability causes changes in plant physiology and Bt expression. Our objective was to determine whether nitrogen and irrigation influenced bollworm behavior in Bt cotton by recording the vertical distribution of eggs and larvae over time. We conducted small plot experiments with Cry1Ac + Cry1F cotton in 2016 and 2017 with three nitrogen rates, along with irrigated and nonirrigated treatments during 2017. Bollworm locations were determined by in-field examination of 10-20 cotton plants per plot over 6-8 wk. The location of each egg and larva was recorded by node, with instar estimation of each larva. Oviposition was higher in in plots receiving nitrogen; first and second instars were also more common in plots receiving nitrogen or irrigation, whereas older instars had similar numbers among treatments. Oviposition was more evenly distributed throughout the canopy earlier in the sampling period than during later weeks, with more eggs in the top third of the canopy in only three of 14-wk. Early instars were also evenly distributed throughout the canopy. Later, instars moved to the middle portions of the canopy, away from bottom nodes, and did not move toward the terminal. Understanding bollworm behavior can inform both crop scouting and resistance management decisions.

Sperm are among the most variable cells in nature. Some of this variation results from nonadaptive errors in spermatogenesis, but many species consistently produce multiple sperm morphs, the adaptive significance of which remains unknown. Here, we investigate the evolution of dimorphic sperm in Lepidoptera, the butterflies and moths. Males of this order produce both fertilizing sperm and a secondary, nonfertilizing type that lacks DNA. Previous organismal studies suggested a role for nonfertilizing sperm in sperm competition, but this hypothesis has never been evaluated from a molecular framework. We combined published data sets with new sequencing in two species, the monandrous Carolina sphinx moth and the highly polyandrous monarch butterfly. Based on population genetic analyses, we see evidence for increased adaptive evolution in fertilizing sperm, but only in the polyandrous species. This signal comes primarily from a decrease in nonsynonymous polymorphism in sperm proteins compared to the rest of the genome, suggesting stronger purifying selection, consistent with selection via sperm competition. Nonfertilizing sperm proteins, in contrast, do not show an effect of mating system and do not appear to evolve differently from the background genome in either species, arguing against the involvement of nonfertilizing sperm in direct sperm competition. Based on our results and previous work, we suggest that nonfertilizing sperm may be used to delay female remating in these insects and decrease the risk of sperm competition rather than directly affect its outcome.

Dioecy is rare among flowering plants, and is associated with a high frequency of threatened species. Dioecious plants are often pollinated by wind or insects, but are susceptible to pollination failure should male and female plants become spatially separated, or should pollinator abundance decline. Here we characterize the plant-pollinator interactions of Rhus michauxii Sarg (Sapindales: Anacardiaceae), an endangered dioecious shrub endemic to the southeastern United States. Working in the sandhills region of North Carolina, we detected a diverse community of arthropods visiting R. michauxii flowers, including 55 species or morphospecies, with moderate niche overlap between male and female flowers. Although most visitors acquired pollen from male flowers, pollen loads were greatly reduced or diluted on visitors to female flowers; conspecific pollen was completely absent at all-female sites. Bees in the genus Megachile appear to be the most important pollen vectors in this system because of their abundance and pollen load composition. We constructed a regional pollen transport network involving 73 arthropod species and 46 pollen species/morphotypes, in which R. michauxii participated in 10% of links and attracted 38% of individual visitors, suggesting that it competes successfully with other plants for visitation. Finally, time-lapse videography revealed that female inflorescences were visited about six times less often than male inflorescences, but at similar times of day. Despite overall high rates of bee visitation, pollen movement from male to female plants was uncommon, and restoration of sexual reproduction in this species may require hand pollination or translocation of suitable mates to single-sex sites.

Bollworm (Helicoverpa zea Boddie) (Lepidoptera: Noctuidae) can cause economic losses in both non-Bt and Bt cotton. Larvae modify their behavior in the presence of Bt by moving away from terminals faster in Bt cotton compared to non-Bt cotton and avoiding Bt-treated diets. Our objectives were to understand differences in bollworm egg and larvae populations within, and dispersal away from, non-Bt and Bt pyramided-toxin cotton. We conducted small plot experiments in 2016 and 2017 to monitor on-plant egg and larval numbers, and off-plant dispersal of larvae, from non-Bt and different Bt toxin pyramided cotton. Bollworm adults preferred to oviposit in most Bt toxin pyramids compared to non-Bt; this was likely unrelated to detection of Bt by adults, but rather density-dependent aversion from high larval populations. First instar numbers were similar in all non-Bt/Bt toxin pyramids and dispersed at a similar rate. Second through fifth instar numbers were higher in non-Bt than Bt toxin pyramids but dispersed equally from all non-Bt/Bt toxin pyramids, regardless of Bt pyramid type. Development times of larvae were often slower in Bt toxin pyramids compared to non-Bt. Fifth instars were found in, and dispersing from, Bt toxin pyramids containing Vip3A, raising concerns of resistance development. Furthermore, differences in oviposition rate among non-Bt/Bt toxin pyramids and slowed development rate of larvae on Bt varieties could create inconsistencies in generation times emerging from Bt and non-Bt hosts, which could contribute to resistance development.

The Earth is experiencing a wave of anthropogenic biodiversity loss, such that current rates of extinction are 100–1,000 times the background rate observed between prior mass extinctions in the fossil record (Barnosky et al. 2011, Pimm et al. 2014). These losses place Earth’s biota in the early stages of an extinction event comparable to those precipitated only five times before in the past 540 million years (Barnosky et al. 2011, Ceballos et al. 2015). Among plants—the foundation of terrestrial food webs—an estimated 20% of all species are currently threatened with extinction (Brummitt et al. 2015). Among invertebrates, conservation status has been reviewed for only about 1% of described species, and of those, some 40% are threatened (Dirzo et al. 2014). Regional surveys regularly detect striking losses in insect biomass and population size over recent decades (e.g., Fox 2013, Hallmann et al. 2017, Lister and Garcia 2018). Loss of species richness, population size, and biomass are striking, but they do not capture the full impact of biotic change. Each species participates in a web of interactions, such as predation, parasitism, and mutualism, that underpin ecosystem functions (Tylianakis et al. 2008). These interactions are expected to disappear before the species themselves (McConkey and Drake 2006, Valiente-Banuet et al. 2015), precipitating changes in ecosystem function and extinction of other species that depend on the interactions (Säterberg et al. 2013, Risch et al. 2018). In this context, the study of rare biotic interactions is becoming more widespread and more urgent; however, challenges abound in detecting such interactions and interpreting their ecological relevance. These challenges were the focus of a Plant-Insect Ecosystems Section Symposium convened at the 2017 annual meeting of the Entomological Society of America in Denver, CO. Among the symposium’s 16 presenters, 6 contributed papers to this collection, providing a cross section of the dimensions of rarity with which ecologists must grapple.

Management of natural habitats is an important strategy for rare plant conservation. One common tool for managing natural habitats is the use of controlled fire. Rare plants in fire-dependent ecosystems often rely on frequent fires to increase nutrient availability, initiate germination, and limit cover from light competitors. Fire can also alter arthropod communities, including the pollinator communities upon which many flowering plants rely for sexual reproduction. However, it remains unclear how fire affects the pollination ecology of rare plants in fire-dependent ecosystems. Here we studied sites of varying burn history to examine the role of time since last fire on the morphology, flower visitor community, and degree of pollen limitation of seed production of Venus flytrap (Dionaea muscipula). The area occupied by blooming D. muscipula and number of traps per individual decreased with increasing time since burn. Though flower visitor richness and evenness were highest in sites of intermediate time post-burn, we found no differences in the composition of the flower visitor community in sites of different burn histories. Hand-pollinated flowers produced 8.3% more seeds per fruit than open-pollinated flowers, indicating that D. muscipula was pollen-limited, but burn history did not affect the magnitude of pollen limitation. Though we found no clear effect of burn history on the pollination ecology of D. muscipula, differences in blooming area and trap number suggest that burn history influences its distribution and growth, and affirms the benefits of frequent fires to its persistence.