@article{hamon_youngsteadt_irwin_sorenson_2024, title={As prey and pollinators, insects increase reproduction and allow for outcrossing in the carnivorous plant <i>Dionaea muscipula}, ISSN={0002-9122 1537-2197}, url={http://dx.doi.org/10.1002/ajb2.16279}, DOI={10.1002/ajb2.16279}, abstractNote={Abstract}, journal={American Journal of Botany}, publisher={Wiley}, author={Hamon, Laura E. and Youngsteadt, Elsa and Irwin, Rebecca E. and Sorenson, Clyde E.}, year={2024}, month={Jan} }
 @article{ruzi_youngsteadt_cherveny_kettenbach_levenson_carley_collazo_irwin_2023, title={Bee species richness through time in an urbanizing landscape of the southeastern <scp>United States}, volume={30}, ISSN={1354-1013 1365-2486}, url={http://dx.doi.org/10.1111/gcb.17060}, DOI={10.1111/gcb.17060}, abstractNote={Abstract}, number={1}, journal={Global Change Biology}, publisher={Wiley}, author={Ruzi, Selina A. and Youngsteadt, Elsa and Cherveny, April Hamblin and Kettenbach, Jessica and Levenson, Hannah K. and Carley, Danesha Seth and Collazo, Jaime A. and Irwin, Rebecca E.}, year={2023}, month={Dec} }
 @article{kirchner_bertone_blaimer_youngsteadt_2023, title={COLONY STRUCTURE AND REDESCRIPTION OF MALES IN THE RARELY COLLECTED ARBOREAL ANT, <i>APHAENOGASTER</i> <i>MARIAE</i> FOREL (HYMENOPTERA: FORMICIDAE)}, volume={125}, ISSN={["0013-8797"]}, DOI={10.4289/0013-8797.125.1.77}, abstractNote={Abstract. Aphaenogaster mariae Forel is a rarely encountered North American arboreal ant that has eluded collectors for decades. Here, we provide the first formal documentation of a whole colony collection of the species found seventeen meters high in the canopy of the North Carolina Piedmont. We discovered a mature colony with more than 1000 individuals, including workers, alate reproductives, immatures, and intercastes. We present the first images of the males, larvae, pupae, and intercaste workers, redescribe the male, and provide natural history insights and colony demographics for this elusive species. Our collections suggest that A. mariae occurs at low densities consistent with its putative socially parasitic life history. Although much remains to be learned about this species, our results expand knowledge of its life history and facilitate future nest discovery and identification.}, number={1}, journal={PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON}, author={Kirchner, Michelle and Bertone, Matthew and Blaimer, Bonnie B. and Youngsteadt, Elsa}, year={2023}, month={Jan}, pages={77–88} }
 @article{youngsteadt_prado_keleher_kirchner_2023, title={Can behaviour and physiology mitigate effects of warming on ectotherms? A test in urban ants}, ISSN={["1365-2656"]}, DOI={10.1111/1365-2656.13860}, abstractNote={Abstract}, journal={JOURNAL OF ANIMAL ECOLOGY}, author={Youngsteadt, Elsa and Prado, Sara Guiti and Keleher, Kirsten Joanna and Kirchner, Michelle}, year={2023}, month={Jan} }
 @article{naumchik_youngsteadt_2023, title={Larger pollen loads increase risk of heat stress in foraging bumblebees}, volume={19}, ISSN={["1744-957X"]}, DOI={10.1098/rsbl.2022.0581}, abstractNote={
            Global declines in bumblebee populations are linked to climate change, but specific mechanisms imposing thermal stress on these species are poorly known. Here we examine the potential for heat stress in workers foraging for pollen, an essential resource for colony development. Laboratory studies have shown that pollen foraging causes increased thoracic temperatures (
            T
            th
            ) in bees, but this effect has not been examined in bumblebees nor in real-world foraging situations. We examine the effects of increasing pollen load size on
            T
            th
            of
            Bombus impatiens
            workers in the field while accounting for body size and microclimate. We found that
            T
            th
            increased by 0.07°C for every milligram of pollen carried (
            p
            = 0.007), resulting in a 2°C increase across the observed range of pollen load sizes. Bees carrying pollen were predicted to have a
            T
            th
            1.7–2.2°C hotter than those without pollen, suggesting that under certain conditions, pollen loads could cause
            B. impatiens
            workers to heat from a safe
            T
            th
            to one within the range of their critical thermal limits that we measured (41.3°C to 48.4°C). Bumblebees likely adopt behavioural or physiological strategies to counteract the thermal stress induced by pollen transport, and these may limit their foraging opportunities as environmental temperatures continue to increase.
          }, number={5}, journal={BIOLOGY LETTERS}, author={Naumchik, Malia and Youngsteadt, Elsa}, year={2023}, month={May} }
 @misc{youngsteadt_keighron_2023, title={Urban Pollination Ecology}, volume={54}, ISSN={["1545-2069"]}, DOI={10.1146/annurev-ecolsys-102221-044616}, abstractNote={Pollination is an essential component of plant reproduction that is transformed by the novel environmental conditions in cities. We summarize patterns of urban plant reproduction and trace the mechanisms by which urban environments influence pollination, beginning at the level of the individual plant. We then progress through several processes unique to animal-pollinated plants, including plant–pollinator signaling, community-level effects, and emergent plant–pollinator interaction networks. Last, we review pollen movement and plant spatial mating networks. Despite a global signal of reduced pollination in urban, animal-pollinated plants, effects vary among studies, and the extent of pollen dispersal through a city remains difficult to predict. We highlight recent progress, as well as areas where new research will help crystallize our understanding of urban pollination. These advances have the potential to spur exciting new insights into network dynamics and pollen movement, and may ultimately inform the sustainable design of urban conservation and ecosystem services.}, journal={ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS}, author={Youngsteadt, Elsa and Keighron, Melina C.}, year={2023}, pages={21–42} }
 @misc{briggs_baranski_munzer schaetz_garrison_collazo_youngsteadt_2022, title={Estimating bee abundance: can mark-recapture methods validate common sampling protocols?}, volume={53}, ISSN={["1297-9678"]}, DOI={10.1007/s13592-022-00919-4}, abstractNote={Abstract}, number={1}, journal={APIDOLOGIE}, author={Briggs, Emma L. and Baranski, Christopher and Munzer Schaetz, Olivia and Garrison, Gabriela and Collazo, Jaime A. and Youngsteadt, Elsa}, year={2022}, month={Mar} }
 @misc{irwin_youngsteadt_warren_bronstein_2020, title={The Evolutionary Ecology of Mutualisms in Urban Landscapes}, ISBN={["978-0-19-883685-8"]}, url={http://dx.doi.org/10.1093/oso/9780198836841.003.0007}, DOI={10.1093/oso/9780198836841.003.0007}, abstractNote={Abstract}, journal={Urban Evolutionary Biology}, publisher={Oxford University PressOxford}, author={Irwin, Rebecca E. and Youngsteadt, Elsa and Warren, Paige S. and Bronstein, Judith L.}, year={2020}, month={May}, pages={111–129} }
 @article{moylett_youngsteadt_sorenson_2020, title={The Impact of Prescribed Burning on Native Bee Communities (Hymenoptera: Apoidea: Anthophila) in Longleaf Pine Savannas in the North Carolina Sandhills}, volume={49}, ISSN={["1938-2936"]}, DOI={10.1093/ee/nvz156}, abstractNote={Abstract}, number={1}, journal={ENVIRONMENTAL ENTOMOLOGY}, author={Moylett, Heather and Youngsteadt, Elsa and Sorenson, Clyde}, year={2020}, month={Feb}, pages={211–219} }
 @article{youngsteadt_lopez-uribe_sorenson_2019, title={Ecology in the Sixth Mass Extinction: Detecting and Understanding Rare Biotic Interactions}, volume={112}, ISSN={["1938-2901"]}, DOI={10.1093/aesa/saz007}, abstractNote={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.}, number={3}, journal={ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA}, author={Youngsteadt, Elsa and Lopez-Uribe, Margarita M. and Sorenson, Clyde E.}, year={2019}, month={May}, pages={119–121} }
 @article{youngsteadt_sorenson_2019, title={Failure of Pollen Transport Despite High Bee Visitation in an Endangered Dioecious Shrub}, volume={112}, ISSN={["1938-2901"]}, DOI={10.1093/aesa/say049}, abstractNote={Abstract 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.}, number={3}, journal={ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA}, author={Youngsteadt, Elsa and Sorenson, Clyde E.}, year={2019}, month={May}, pages={169–179} }
 @book{levenson_youngsteadt_2019, place={Raleigh, North Carolina}, title={The bees of North Carolina : an identification guide}, publisher={NC State Extension}, author={Levenson, Hannah and Youngsteadt, Elsa}, year={2019} }
 @misc{terando_youngsteadt_meineke_prado_2018, title={Accurate near surface air temperature measurements are necessary to gauge large-scale ecological responses to global climate change}, volume={8}, ISSN={["2045-7758"]}, DOI={10.1002/ece3.3972}, abstractNote={Linked Article: https://doi.org/10.1002/ece3.3965}, number={11}, journal={ECOLOGY AND EVOLUTION}, author={Terando, Adam and Youngsteadt, Elsa and Meineke, Emily and Prado, Sara}, year={2018}, month={Jun}, pages={5233–5234} }
 @article{terando_prado_youngsteadt_2018, title={Construction of a Compact Low-Cost Radiation Shield for Air-Temperature Sensors in Ecological Field Studies}, ISSN={["1940-087X"]}, DOI={10.3791/58273}, abstractNote={Low cost temperature sensors are increasingly used by ecologists to assess climatic variation and change on ecologically relevant scales. Although cost-effective, if not deployed with proper solar radiation shielding, the observations recorded from these sensors will be biased and inaccurate. Manufactured radiation shields are effective at minimizing this bias, but are expensive compared to the cost of these sensors. Here, we provide a detailed methodology for constructing a compact version of a previously described custom fabricated radiation shield, which is more accurate than other published shielding methods that attempt to minimize shield size or construction costs. The method requires very little material: corrugated plastic sheets, aluminum foil duct tape, and cable ties. One 15 cm and two 10 cm squares of corrugated plastic are used for each shield. After cutting, scoring, taping and stapling of the sheets, the 10 cm squares form the bottom two layers of the solar radiation shield, while the 15 cm square forms the top layer. The three sheets are held together with cable ties. This compact solar radiation shield can be suspended, or placed against any flat surface. Care must be taken to ensure that the shield is completely parallel to the ground to prevent direct solar radiation from reaching the sensor, possibly causing increased warm biases in sun-exposed sites in the morning and afternoon relative to the original, larger design. Even so, differences in recorded temperatures between the smaller, compact shield design and the original design were small (mean daytime bias = 0.06 °C). Construction costs are less than half of the original shield design, and the new design results in a less conspicuous instrument that may be advantageous in many field ecology settings.}, number={141}, journal={JOVE-JOURNAL OF VISUALIZED EXPERIMENTS}, author={Terando, Adam J. and Prado, Sara G. and Youngsteadt, Elsa}, year={2018}, month={Nov} }
 @article{savage_youngsteadt_ernst_powers_dunn_frank_2018, title={Homogenizing an urban habitat mosaic: arthropod diversity declines in New York City parks after Super Storm Sandy}, volume={28}, ISSN={["1939-5582"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85040223231&partnerID=MN8TOARS}, DOI={10.1002/eap.1643}, abstractNote={Abstract}, number={1}, journal={ECOLOGICAL APPLICATIONS}, author={Savage, Amy M. and Youngsteadt, Elsa and Ernst, Andrew F. and Powers, Shelby A. and Dunn, Robert R. and Frank, Steven D.}, year={2018}, month={Jan}, pages={225–236} }
 @article{hamon_youngsteadt_irwin_sorenson_2018, title={Pollination Ecology and Morphology of Venus Flytrap in Sites of Varying Time Since Last Fire}, volume={112}, ISSN={0013-8746 1938-2901}, url={http://dx.doi.org/10.1093/aesa/say032}, DOI={10.1093/aesa/say032}, abstractNote={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 Ellis) (Caryophyllales: Droseraceae). 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.}, number={3}, journal={Annals of the Entomological Society of America}, publisher={Oxford University Press (OUP)}, author={Hamon, Laura E and Youngsteadt, Elsa and Irwin, Rebecca E and Sorenson, Clyde E}, year={2018}, month={Sep}, pages={141–149} }
 @article{youngsteadt_irwin_fowler_bertone_giacomini_kunz_suiter_sorenson_2018, title={Venus Flytrap Rarely Traps Its Pollinators}, volume={191}, ISSN={0003-0147 1537-5323}, url={http://dx.doi.org/10.1086/696124}, DOI={10.1086/696124}, abstractNote={Because carnivorous plants rely on arthropods as pollinators and prey, they risk consuming would-be mutualists. We examined this potential conflict in the Venus flytrap (Dionaea muscipula), whose pollinators were previously unknown. Diverse arthropods from two classes and nine orders visited flowers; 56% of visitors carried D. muscipula pollen, often mixed with pollen of coflowering species. Within this diverse, generalized community, certain bee and beetle species appear to be the most important pollinators, on the basis of their abundance, pollen load size, and pollen fidelity. Dionaea muscipula prey spanned four invertebrate classes and 11 orders; spiders, beetles, and ants were most common. At the family and species levels, few taxa were shared between traps and flowers, yielding a near-zero value of niche overlap for these potentially competing structures. Spatial separation of traps and flowers may contribute to partitioning the invertebrate community between nutritional and reproductive functions in D. muscipula.}, number={4}, journal={The American Naturalist}, publisher={University of Chicago Press}, author={Youngsteadt, Elsa and Irwin, Rebecca E. and Fowler, Alison and Bertone, Matthew A. and Giacomini, Sara June and Kunz, Michael and Suiter, Dale and Sorenson, Clyde E.}, year={2018}, month={Apr}, pages={539–546} }
 @article{hamblin_youngsteadt_frank_2018, title={Wild bee abundance declines with urban warming, regardless of floral density}, volume={21}, DOI={10.1007/s11252-018-0731-4}, number={3}, journal={Urban Ecosystems}, author={Hamblin, A. L. and Youngsteadt, E. and Frank, Steven}, year={2018}, pages={419–428} }
 @article{lopez-uribe_appler_youngsteadt_dunn_frank_tarpy_2017, title={Higher immunocompetence is associated with higher genetic diversity in feral honey bee colonies (Apis mellifera)}, volume={18}, ISSN={["1572-9737"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85013371895&partnerID=MN8TOARS}, DOI={10.1007/s10592-017-0942-x}, number={3}, journal={CONSERVATION GENETICS}, author={Lopez-Uribe, Margarita M. and Appler, R. Holden and Youngsteadt, Elsa and Dunn, Robert R. and Frank, Steven D. and Tarpy, David R.}, year={2017}, month={Jun}, pages={659–666} }
 @article{hamblin_youngsteadt_lopez-uribe_frank_2017, title={Physiological thermal limits predict differential responses of bees to urban heat-island effects}, volume={13}, ISSN={["1744-957X"]}, DOI={10.1098/rsbl.2017.0125}, abstractNote={
            Changes in community composition are an important, but hard to predict, effect of climate change. Here, we use a wild-bee study system to test the ability of critical thermal maxima (CT
            max
            , a measure of heat tolerance) to predict community responses to urban heat-island effects in Raleigh, NC, USA. Among 15 focal species, CT
            max
            ranged from 44.6 to 51.3°C, and was strongly predictive of population responses to urban warming across 18 study sites (
            r
            2
            = 0.44). Species with low CT
            max
            declined the most. After phylogenetic correction, solitary species and cavity-nesting species (bumblebees) had the lowest CT
            max
            , suggesting that these groups may be most sensitive to climate change. Community responses to urban and global warming will likely retain strong physiological signal, even after decades of warming during which time lags and interspecific interactions could modulate direct effects of temperature.
          }, number={6}, journal={BIOLOGY LETTERS}, author={Hamblin, April L. and Youngsteadt, Elsa and Lopez-Uribe, Margarita M. and Frank, Steven D.}, year={2017}, month={Jun} }
 @article{youngsteadt_ernst_dunn_frank_2017, title={Responses of arthropod populations to warming depend on latitude: evidence from urban heat islands}, volume={23}, ISSN={["1365-2486"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85006106453&partnerID=MN8TOARS}, DOI={10.1111/gcb.13550}, abstractNote={Abstract}, number={4}, journal={GLOBAL CHANGE BIOLOGY}, author={Youngsteadt, Elsa and Ernst, Andrew F. and Dunn, Robert R. and Frank, Steven D.}, year={2017}, month={Apr}, pages={1436–1447} }
 @article{reese_savage_youngsteadt_mcguire_koling_watkins_frank_dunn_2016, title={Urban stress is associated with variation in microbial species composition-but not richness-in Manhattan}, volume={10}, ISSN={["1751-7370"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84942133913&partnerID=MN8TOARS}, DOI={10.1038/ismej.2015.152}, abstractNote={Abstract}, number={3}, journal={ISME JOURNAL}, author={Reese, Aspen T. and Savage, Amy and Youngsteadt, Elsa and McGuire, Krista L. and Koling, Adam and Watkins, Olivia and Frank, Steven D. and Dunn, Robert R.}, year={2016}, month={Mar}, pages={751–760} }
 @article{meineke_youngsteadt_dunn_frank_2016, title={Urban warming reduces aboveground carbon storage}, volume={283}, ISSN={0962-8452 1471-2954}, url={http://dx.doi.org/10.1098/rspb.2016.1574}, DOI={10.1098/rspb.2016.1574}, abstractNote={A substantial amount of global carbon is stored in mature trees. However, no experiments to date test how warming affects mature tree carbon storage. Using a unique, citywide, factorial experiment, we investigated how warming and insect herbivory affected physiological function and carbon sequestration (carbon stored per year) of mature trees. Urban warming increased herbivorous arthropod abundance on trees, but these herbivores had negligible effects on tree carbon sequestration. Instead, urban warming was associated with an estimated 12% loss of carbon sequestration, in part because photosynthesis was reduced at hotter sites. Ecosystem service assessments that do not consider urban conditions may overestimate urban tree carbon storage. Because urban and global warming are becoming more intense, our results suggest that urban trees will sequester even less carbon in the future.}, number={1840}, journal={Proceedings of the Royal Society B: Biological Sciences}, publisher={The Royal Society}, author={Meineke, Emily and Youngsteadt, Elsa and Dunn, Robert R. and Frank, Steven D.}, year={2016}, month={Oct}, pages={20161574} }
 @article{youngsteadt_dale_terando_dunn_frank_2015, title={Do cities simulate climate change? A comparison of herbivore response to urban and global warming}, volume={21}, ISSN={["1365-2486"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84916930773&partnerID=MN8TOARS}, DOI={10.1111/gcb.12692}, abstractNote={Abstract}, number={1}, journal={GLOBAL CHANGE BIOLOGY}, author={Youngsteadt, Elsa and Dale, Adam G. and Terando, Adam J. and Dunn, Robert R. and Frank, Steven D.}, year={2015}, month={Jan}, pages={97–105} }
 @article{youngsteadt_henderson_savage_ernst_dunn_frank_2015, title={Habitat and species identity, not diversity, predict the extent of refuse consumption by urban arthropods}, volume={21}, ISSN={["1365-2486"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84923107777&partnerID=MN8TOARS}, DOI={10.1111/gcb.12791}, abstractNote={Abstract}, number={3}, journal={GLOBAL CHANGE BIOLOGY}, author={Youngsteadt, Elsa and Henderson, Ryanna C. and Savage, Amy M. and Ernst, Andrew F. and Dunn, Robert R. and Frank, Steven D.}, year={2015}, month={Mar}, pages={1103–1115} }
 @article{youngsteadt_appler_lopez-uribe_tarpy_frank_2015, title={Urbanization Increases Pathogen Pressure on Feral and Managed Honey Bees}, volume={10}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0142031}, abstractNote={Given the role of infectious disease in global pollinator decline, there is a need to understand factors that shape pathogen susceptibility and transmission in bees. Here we ask how urbanization affects the immune response and pathogen load of feral and managed colonies of honey bees (Apis mellifera Linnaeus), the predominant economically important pollinator worldwide. Using quantitative real-time PCR, we measured expression of 4 immune genes and relative abundance of 10 honey bee pathogens. We also measured worker survival in a laboratory bioassay. We found that pathogen pressure on honey bees increased with urbanization and management, and the probability of worker survival declined 3-fold along our urbanization gradient. The effect of management on pathogens appears to be mediated by immunity, with feral bees expressing immune genes at nearly twice the levels of managed bees following an immune challenge. The effect of urbanization, however, was not linked with immunity; instead, urbanization may favor viability and transmission of some disease agents. Feral colonies, with lower disease burdens and stronger immune responses, may illuminate ways to improve honey bee management. The previously unexamined effects of urbanization on honey-bee disease are concerning, suggesting that urban areas may favor problematic diseases of pollinators.}, number={11}, journal={PLOS ONE}, author={Youngsteadt, Elsa and Appler, R. Holden and Lopez-Uribe, Margarita M. and Tarpy, David R. and Frank, Steven D.}, year={2015}, month={Nov} }
 @article{youngsteadt_guerra bustios_schal_2010, title={Divergent Chemical Cues Elicit Seed Collecting by Ants in an Obligate Multi-Species Mutualism in Lowland Amazonia}, volume={5}, ISSN={1932-6203}, url={http://dx.doi.org/10.1371/journal.pone.0015822}, DOI={10.1371/journal.pone.0015822}, abstractNote={In lowland Amazonian rainforests, specific ants collect seeds of several plant species and cultivate them in arboreal carton nests, forming species-specific symbioses called ant-gardens (AGs). In this obligate mutualism, ants depend on the plants for nest stability and the plants depend on ant nests for substrate and nutrients. AG ants and plants are abundant, dominant members of lowland Amazonian ecosystems, but the cues ants use to recognize the seeds are poorly understood. To address the chemical basis of the ant-seed interaction, we surveyed seed chemistry in nine AG species and eight non-AG congeners. We detected seven phenolic and terpenoid volatiles common to seeds of all or most of the AG species, but a blend of the shared compounds was not attractive to the AG ant Camponotus femoratus. We also analyzed seeds of three AG species (Anthurium gracile, Codonanthe uleana, and Peperomia macrostachya) using behavior-guided fractionation. At least one chromatographic fraction of each seed extract elicited retrieval behavior in C. femoratus, but the active fractions of the three plant species differed in polarity and chemical composition, indicating that shared compounds alone did not explain seed-carrying behavior. We suggest that the various AG seed species must elicit seed-carrying with different chemical cues.}, number={12}, journal={PLoS ONE}, publisher={Public Library of Science (PLoS)}, author={Youngsteadt, Elsa and Guerra Bustios, Patricia and Schal, Coby}, editor={Leal, Walter S.Editor}, year={2010}, month={Dec}, pages={e15822} }
 @article{booth_youngsteadt_schal_vargo_2009, title={Characterization of 8 polymorphic microsatellite loci in the neotropical ant-garden ant, Camponotus femoratus (Fabricius)}, volume={10}, ISSN={["1572-9737"]}, DOI={10.1007/s10592-008-9705-z}, number={5}, journal={CONSERVATION GENETICS}, author={Booth, Warren and Youngsteadt, Elsa and Schal, Coby and Vargo, Edward L.}, year={2009}, month={Oct}, pages={1401–1403} }
 @article{booth_youngsteadt_schal_vargo_2009, title={Polymorphic microsatellite loci for the ant-garden ant, Crematogaster levior (Forel)}, volume={10}, ISSN={["1572-9737"]}, DOI={10.1007/s10592-008-9597-y}, abstractNote={Throughout Amazonia, the ant Crematogaster levior is known for its participation in a complex ant-garden mutualism with the ant Camponotus femoratus and several species of epiphytic plants for which it plays an important role in seed viability. We isolated nine polymorphic microsatellite loci for C. levior from a genomic library enriched for di-, tri-, and tetra-nucleotide repeats. Two to 14 alleles were detected per locus, with levels of observed heterozygosity ranging from 0.103 to 0.785.}, number={3}, journal={CONSERVATION GENETICS}, author={Booth, Warren and Youngsteadt, Elsa and Schal, Coby and Vargo, Edward L.}, year={2009}, month={Jun}, pages={639–641} }
 @article{youngsteadt_baca_osborne_schal_2009, title={Species-specific seed dispersal in an obligate ant-plant mutualism}, volume={4}, number={2}, journal={PLoS One}, author={Youngsteadt, E. and Baca, J. A. and Osborne, J. and Schal, C.}, year={2009} }
 @article{youngsteadt_nojima_haberlein_schulz_schal_2008, title={Seed odor mediates an obligate ant-plant mutualism in Amazonian rainforests}, volume={105}, ISSN={0027-8424 1091-6490}, url={http://dx.doi.org/10.1073/pnas.0708643105}, DOI={10.1073/pnas.0708643105}, abstractNote={
            Seed dispersal mutualisms are essential for the survival of diverse plant species and communities worldwide. Among invertebrates, only ants have a major role in seed dispersal, and thousands of plant species produce seeds specialized for ant dispersal in “diffuse” multispecies interactions. An outstanding but poorly understood ant–seed mutualism occurs in the Amazonian rainforest, where arboreal ants collect seeds of several epiphyte species and cultivate them in nutrient-rich nests, forming abundant and conspicuous hanging gardens known as ant-gardens (AGs). AG ants and plants are dominant members of lowland Amazonian ecosystems, and their interaction is both specific and obligate, but the means by which ants locate, recognize, and accept their mutualist seeds while rejecting other seeds is unknown. Here we address the chemical and behavioral basis of the AG interaction. We show that workers of the AG ant
            Camponotus femoratus
            are attracted to odorants emanating from seeds of the AG plant
            Peperomia macrostachya
            , and that chemical cues also elicit seed-carrying behavior. We identify five compounds from
            P. macrostachya
            seeds that, as a blend, attract
            C. femoratus
            workers. This report of attractive odorants from ant-dispersed seeds illustrates the intimacy and complexity of the AG mutualism and begins to illuminate the chemical basis of this important and enigmatic interaction.
          }, number={12}, journal={Proceedings of the National Academy of Sciences}, publisher={Proceedings of the National Academy of Sciences}, author={Youngsteadt, E. and Nojima, S. and Haberlein, C. and Schulz, S. and Schal, C.}, year={2008}, month={Jan}, pages={4571–4575} }
 @article{youngsteadt_fan_stay_schal_2005, title={Cuticular hydrocarbon synthesis and its maternal provisioning to embryos in the viviparous cockroach Diploptera punctata}, volume={51}, ISSN={["1879-1611"]}, DOI={10.1016/j.jinsphys.2005.03.008}, abstractNote={Embryos of the viviparous cockroach Diploptera punctata accumulate large amounts of hydrocarbon (HC) of either maternal or embryonic origin. HC synthesis and its accumulation in maternal and embryonic tissues were measured over the course of gestation. Female abdominal integument was the only tissue that synthesized appreciable amounts of HC in vitro, and did so at an increasing rate from the time of mating to mid-pregnancy, when rates of synthesis declined. The embryos synthesized HC at rates <1% those of the female, showing that the majority of HC detected in and on embryos was of maternal origin. The brood sac that houses the developing embryos did not synthesize HC in vitro, indicating that HC must be transported from the female abdominal integument to the embryos. The mass of female epicuticular HC was constant at ∼183 μg, while her internal HC increased fourfold from mating to mid-pregnancy, then declined until parturition. The decline in internal HC reflected both declining HC synthesis in the female and greater export to the embryos, as embryonic internal HC increased 250-fold prior to parturition. An external HC coating over the oothecal covering and chorion of the embryos increased to mid-pregnancy, then declined. Unlike oviparous cockroaches, D. punctata females fed throughout the reproductive cycle, reflecting the nutritional demands of continuously provisioning the developing embryos.}, number={7}, journal={JOURNAL OF INSECT PHYSIOLOGY}, author={Youngsteadt, E and Fan, YL and Stay, B and Schal, C}, year={2005}, month={Jul}, pages={803–809} }
 @article{youngsteadt_devries_2005, title={The effects of ants on the entomophagous butterfly caterpillar Feniseca tarquinius, and the putative role of chemical camouflage in the Feniseca-Ant interaction}, volume={31}, ISSN={["1573-1561"]}, DOI={10.1007/s10886-005-6079-2}, abstractNote={Butterfly caterpillars in the lycaenid subfamily Miletinae are predators of ant-tended Homoptera, yet they lack specialized secretory and call-production organs crucial to ant association in other lycaenids. Here, we address the question of how miletine caterpillars have invaded the ant-Homoptera symbiosis through a study of the only New World miletine, Feniseca tarquinius, a predator of the wooly aphid Prociphilus tesselatus. Previous interpretations have suggested that F. tarquinius and other miletine caterpillars avoid ant aggression by concealing themselves under silken webs. In contrast, our field data indicate that F. tarquinius caterpillars are less likely to be concealed in the presence of the ants Camponotus pennsylvanicus and Formica obscuriventris than in the absence of ants, although caterpillar and ant behaviors vary between years. Chemical analysis and behavioral assays suggest that chemical camouflage, not physical concealment, is responsible for the ants' failure to detect and remove F. tarquinius caterpillars from aphid colonies. Analyses by gas chromatography indicate that the cuticular lipid composition of caterpillars are similar to that of their aphid prey, although it varies with prey species. Behavioral assays confirm that solvent extracts of F. tarquinius caterpillars and P. tesselatus aphids evoke similar behavioral responses in C. pennsylvanicus ants. Chemical camouflage is well known in social parasites of ants, but the present study represents one of a few documented cases where chemical deceit is important to interactions with ants outside the nest.}, number={9}, journal={JOURNAL OF CHEMICAL ECOLOGY}, author={Youngsteadt, E and Devries, PJ}, year={2005}, month={Sep}, pages={2091–2109} }