@article{youngsteadt_prado_aquino_valdeiglesias_ojeda_quispe_2024, title={Urbanization drives partner switching and loss of mutualism in an ant-plant symbiosis}, ISSN={["1939-9170"]}, DOI={10.1002/ecy.4449}, abstractNote={Abstract Mutualistic interactions between species underpin biodiversity and ecosystem function, but may be lost when partners respond differently to abiotic conditions. Except for a few prominent examples, effects of global anthropogenic change on mutualisms are poorly understood. Here we assess the effects of urbanization on a symbiosis in which the plant Cordia nodosa house ants in hollow structures (domatia) in exchange for defense against herbivores. We expected to find that mutualist ants would be replaced in the city by heat‐tolerant opportunists, leaving urban plants vulnerable to herbivory. In five protected forest sites and five urban forest fragments in southeast Perú, we recorded the identity and heat tolerance (CT max ) of ant residents of C. nodosa . We also assayed their plant‐defensive behaviors and their effects on herbivory. We characterized the urban heat‐island effect in ambient temperatures and within domatia. Forest plants housed a consistent ant community dominated by three specialized plant ants, whereas urban plants housed a suite of 10 opportunistic taxa that were, collectively, about 13 times less likely than forest ants to respond defensively to plant disturbance. In the forest, ant exclusion had the expected effect of increasing herbivory, but in urban sites, exclusion reduced herbivory. Despite poor ant defense in urban sites, we detected no difference in total standing herbivory, perhaps because herbivores themselves also declined in the city. Urban sites were warmer than forest sites (daily maxima in urban domatia averaged 1.6°C hotter), and the urban ant community as a whole was slightly more heat tolerant. These results illustrate a case of mutualism loss associated with anthropogenic disturbance. If urbanization is representative of increasing anthropogenic stressors more broadly, we might expect to see destabilization of myrmecophytic mutualisms in forest ecosystems in the future.}, journal={ECOLOGY}, author={Youngsteadt, Elsa and Prado, Sara Guiti and Aquino, Alexandra Karlyz Duran and Valdeiglesias, Joel Pena and Ojeda, Therany Gonzales and Quispe, Jorge Santiago Garate}, year={2024}, month={Oct} }
 @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


Global climate change is expected to have pervasive effects on the diversity and distribution of species, particularly ectotherms whose body temperatures depend on environmental temperatures. However, these impacts remain difficult to predict, in part because ectotherms may adapt or acclimate to novel conditions or may use behavioural thermoregulation to reduce their exposure to stressful microclimates.

Here we examine the potential for physiological and behavioural changes to mitigate effects of environmental warming on five species of ants in a temperate forest habitat subject to urban warming.

We worked in eight urban and eight non‐urban forest sites in North Carolina, USA; sites experienced a 1.1°C range of mean summer air temperatures. At each site, we documented species‐specific microclimates (ant operative temperatures, Te) and ant activity on a transect of 14 bait stations at three times of day. In the laboratory, we measured upper thermal tolerance (CTmax) and thermal preference (Tpref) for each focal species. We then asked whether thermal traits shifted at hotter sites, and whether ants avoided non‐preferred microclimates in the field.

CTmax and Tpref did not increase at warmer sites, indicating that these populations did not adapt or acclimate to urban warming. Consistent with behavioural thermoregulation, four of the five species were less likely to occupy baits where Te departed from Tpref. Apparent thermoregulation resulted from fixed diel activity patterns that helped ants avoid the most inappropriate temperatures but did not compensate for daily or spatial temperature variation: Hotter sites had hotter ants.

This study uses a novel approach to detect behavioural thermoregulation and sublethal warming in foraging insects. The results suggest that adaptation and behaviour may not protect common temperate forest ants from a warming climate, and highlight the need to evaluate effects of chronic, sublethal warming on small ectotherms.

}, journal={JOURNAL OF ANIMAL ECOLOGY}, author={Youngsteadt, Elsa and Prado, Sara Guiti and Keleher, Kirsten Joanna and Kirchner, Michelle}, year={2023}, month={Jan} }
 @article{prado_collazo_marand_irwin_2021, title={The influence of floral resources and microclimate on pollinator visitation in an agro-ecosystem}, volume={307}, ISSN={["1873-2305"]}, DOI={10.1016/j.agee.2020.107196}, abstractNote={As agriculture expands to meet the needs of a growing global population, natural ecosystems are threatened by deforestation and habitat fragmentation. Tropical agroforestry systems offer a sustainable alternative to traditional agriculture by providing food for production while also supporting biodiversity and ecosystem services. Previous studies have shown that these systems may even improve crop pollination, but the mechanisms of how these improvements occur are still poorly understood. Using coffee as a focal crop, we explored how microclimatic conditions affected nectar traits (sugar and caffeine concentration) important for pollinator visitation. We also studied how microclimate, floral traits, floral availability at the coffee plant level, availability of floral resources provided by other plant species in the agroecosystem ("neighborhood floral availability"), and the presence of other bees affected the amount of time bees spent foraging on coffee flowers and the proportion of coffee pollen carried on their bodies. We explored these factors using the two dominant coffee species farmed on Puerto Rico, Coffea canephora and C. arabica, under sun and shade management. We found that high nectar sugar concentration and temperature were important predictors of short floral visits (<15s), while increased numbers of bees and open coffee flowers were important predictors of longer floral visits (16–180 seconds). High nectar caffeine concentration was an important predictor of longer visits on C. arabica flowers while the opposite was observed for C. canephora flowers. For both species, high coffee floral availability was the main predicting factor for the proportion of coffee pollen on the bees' bodies. Surprisingly, neither neighborhood floral availability nor the type of coffee plantation (agroforest/shade or sun) were important predictors of bee visitation. These results suggest non-coffee flowering plants in coffee plantations were neither competitors nor facilitators of coffee plants for pollinators. Additionally, most of the bees surveyed were carrying ≥80 % pollen from one species (C. arabica or C. canephora), likely resulting in little heterospecific pollen deposition between Coffea and non-Coffea flowers. Shade trees in coffee plantations do not detract from pollinator visitation to coffee flowers, suggesting that the provision of multiple ecological and wildlife conservation benefits by shade trees is not in conflict with a grower's ability to maximize the benefits of insect pollination on fruit production.}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={Prado, Sara Guiti and Collazo, Jaime A. and Marand, Mariam H. and Irwin, Rebecca E.}, year={2021}, month={Feb} }
 @article{prado_collazo_stevenson_irwin_2019, title={A comparison of coffee floral traits under two different agricultural practices}, volume={9}, ISSN={2045-2322}, url={http://dx.doi.org/10.1038/s41598-019-43753-y}, DOI={10.1038/s41598-019-43753-y}, abstractNote={AbstractFloral traits and rewards are important in mediating interactions between plants and pollinators. Agricultural management practices can affect abiotic factors known to influence floral traits; however, our understanding of the links between agricultural practices and floral trait expression is still poorly understood. Variation in floral morphological, nectar, and pollen traits of two important agricultural species, Coffea arabica and C. canephora, was assessed under different agricultural practices (sun and shade). Corolla diameter and corolla tube length were larger and pollen total nitrogen content greater in shade plantations of C. canephora than sun plantations. Corolla tube length and anther filament length were larger in shade plantations of C. arabica. No effect of agricultural practice was found on nectar volume, sugar or caffeine concentrations, or pollen production. Pollen total nitrogen content was lower in sun than shade plantations of C. canephora, but no difference was found between sun and shade for C. arabica. This study provides baseline data on the influence of agronomic practices on C. arabica and C. canephora floral traits and also helps fill a gap in knowledge about the effects of shade trees on floral traits, which can be pertinent to other agroforestry systems.}, number={1}, journal={Scientific Reports}, publisher={Springer Science and Business Media LLC}, author={Prado, Sara Guiti and Collazo, Jaime A. and Stevenson, Philip C. and Irwin, Rebecca E.}, year={2019}, month={May} }
 @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{prado_collazo_irwin_2018, title={Resurgence of specialized shade coffee cultivation: Effects on pollination services and quality of coffee production}, volume={265}, ISSN={0167-8809}, url={http://dx.doi.org/10.1016/j.agee.2018.07.002}, DOI={10.1016/j.agee.2018.07.002}, abstractNote={Since the early 2000s, there has been a resurgence in shade coffee production on the island of Puerto Rico. The newly restored specialized shade canopy consists of four native tree species, three of which are nitrogen fixers, and is intended to provide 30% shade cover once the trees are matured. Though much is known about the benefits of rustic and traditional shade plantations to coffee production, there is little information available for specialized shade plantations. Here, we investigate the ways in which fruit set, seed predation, bean weight, proportion of peaberries (i.e., malformed fruits), and beverage quality differ between sun and specialized shade plantations of Coffea arabica and Coffea canephora. Additionally, to assess whether coffee plants were pollen limited, we conducted a pollen supplementation experiment in which we compared pollen deposition and berry production on hand-pollinated branches to those of naturally, open-pollinated ones. We found that there was no evidence of pollen limitation on fruit set between sun and specialized shade plantations of C. arabica or C. canephora. We found that specialized shade benefits the proportion of C. arabica fruit set, without compromising bean weight or the proportion of peaberries produced. In comparison, C. canephora showed no improvement in the proportion of fruits set with specialized shade; however, beans from open-pollinated flowers weighed more in specialized shade than sun. Beverage quality was marginally better under shade, and for hand-pollinated flowers. Our results add to the limited body of work investigating the benefits of specialized shade coffee plantations on ecosystem services.}, journal={Agriculture, Ecosystems & Environment}, publisher={Elsevier BV}, author={Prado, Sara Guiti and Collazo, Jaime A. and Irwin, Rebecca E.}, year={2018}, month={Oct}, pages={567–575} }
 @article{prado_frank_2014, title={Optimal foraging by an aphid parasitoid affects the outcome of apparent competition}, volume={39}, DOI={10.1111/een.12093}, abstractNote={
Apparent competition is an indirect, negative interaction occurring between two or more host species, mediated by a shared parasitoid. Host species' population growth rates, parasitoid attack rates, and parasitoid population size can mediate the outcomes of apparent competition. It has also been suggested that optimal foraging by a natural enemy can influence the outcome of apparent competition, resulting in increased suppression of the optimal host.
While this has been shown in theory, to date no studies have empirically tested the link between parasitoid optimal foraging behaviour and the outcome of apparent competition.
The present study examined how optimal foraging behaviour influences the outcome of apparent competition in an aphid banker plant system. First, Aphidius colemani Viereck's preference for Myzus persicae Sulzer or Rhopalosiphum padi L., the non‐pest host on the banker plant, was examined, and then the difference in M. persicae suppression in the presence and absence of R. padi was assessed.
It was found that optimal foraging behaviour led female A. colemani to prefer M. persicae over R. padi, due to increased offspring survival and female size. Consequently, optimally foraging A. colemani parasitised significantly more M. persicae in the presence of both aphid hosts than in the presence of M. persicae alone.
Understanding the interaction between optimal foraging and apparent competition has important implications for biological control of arthropod pests and could help to predict the outcome of biological control programmes.
}, number={2}, journal={Ecological Entomology}, author={Prado, S. G. and Frank, Steven}, year={2014} }
 @article{prado_frank_2013, title={Compact plants reduce biological control of Myzus persicae by Aphidius colemani}, volume={65}, ISSN={["1090-2112"]}, DOI={10.1016/j.biocontrol.2013.03.004}, abstractNote={Common horticultural practices, such as the use of plant growth regulators, may negatively influence the outcome of biological control programs. Plant growth regulators are applied to many ornamental and agricultural crops and can result in compact plants that have more branches and are bushier than untreated plants. Since plant architectural complexity can have strong effects on natural enemy foraging efficiency and pest suppression, our hypothesis was that the use of plant growth regulators would reduce aphid suppression by the parasitoid Aphidius colemani. In this study we investigated how the plant growth regulator paclobutrazol and the parasitic wasp A. colemani interact to affect the abundance and behavior of Myzus persicae. We found that paclobutrazol alone reduced aphid abundance compared to untreated plants. However, when parasitoids were present, paclobutrazol and associated changes in plant architecture reduced parasitism and increased aphid abundance compared to untreated plants. A likely mechanism for this result is that significantly more M. persicae fed in concealed locations on paclobutrazol-treated plants than on untreated plants. This study demonstrates that paclobutrazol reduced the efficacy of biological control by A. colemani and suggests that plant growth regulators could also affect biological control of other organisms.}, number={2}, journal={BIOLOGICAL CONTROL}, author={Prado, Sara Guiti and Frank, Steven D.}, year={2013}, month={May}, pages={184–189} }
 @article{prado_frank_2013, title={Tritrophic effects of plant growth regulators in an aphid-parasitoid system}, volume={66}, ISSN={["1090-2112"]}, DOI={10.1016/j.biocontrol.2013.03.019}, abstractNote={Plant growth regulators (PGRs) have the potential to negatively affect the outcome of biological control via plant architectural changes and plant chemical changes. Despite studies demonstrating the negative effects of PGRs on herbivore survival and development, to date, no studies have investigated the tritrophic effects of PGRs on parasitoid life history traits. In this study we investigated the effect of four commonly used PGRs on Myzus persicae abundance and suppression, and Aphidius colemani fitness in a greenhouse experiment. None of the PGRs reduced aphid abundance alone or affected aphid suppression by A. colemani. However, paclobutrazol reduced the number of mummies that developed on plants. PGRs had a range of negative effects on parasitoid fitness. No adult parasitoids eclosed from mummies on ancymidol treated plants. Paclobutrazol reduced parasitoid size, and paclobutrazol and uniconazole reduced female:total ratio. This study shows that PGRs can negatively affect parasitoid fitness, and reduce parasitism, suggesting the potential for negative long-term effects on the efficacy of biological control.}, number={1}, journal={BIOLOGICAL CONTROL}, author={Prado, Sara G. and Frank, Steven D.}, year={2013}, month={Jul}, pages={72–76} }