TY - JOUR TI - Within-Colony Transmission of Microsporidian and Trypanosomatid Parasites in Honey Bee and Bumble Bee Colonies AU - Pinilla-Gallego, Mario S AU - Williams, Emma E AU - Davis, Abby AU - Fitzgerald, Jacquelyn L AU - McArt, Scott H AU - Irwin, Rebecca E T2 - Environmental Entomology AB - Abstract Parasites are commonly cited as one of the causes of population declines for both managed and wild bees. Epidemiological models sometimes assume that increasing the proportion of infected individuals in a group should increase transmission. However, social insects exhibit behaviors and traits which can dampen the link between parasite pressure and disease spread. Understanding patterns of parasite transmission within colonies of social bees has important implications for how to control diseases within those colonies, and potentially the broader pollinator community. We used bumble bees (Bombus impatiens Cresson) (Hymenoptera: Apidae) and western honey bees (Apis mellifera L.) (Hymenoptera: Apidae) infected with the gut parasites Crithidia bombi (Lipa & Triggiani) (Trypanosomatida: Trypanosomatidae) and Nosema ceranae (Fries et al.) (Dissociodihaplophasida: Nosematidae), respectively, to understand how the initial proportion of infected individuals impacts within-colony spread and intensity of infection of the parasites. In bumble bees, we found that higher initial parasite prevalence increased both the final prevalence and intensity of infection of C. bombi. In honey bees, higher initial prevalence increased the intensity of infection in individual bees, but not the final prevalence of N. ceranae. Measures that reduce the probability of workers bringing parasites back to the nest may have implications for how to control transmission and/or severity of infection and disease outbreaks, which could also have important consequences for controlling disease spread back into the broader bee community. DA - 2020/9/22/ PY - 2020/9/22/ DO - 10.1093/ee/nvaa112 VL - 49 IS - 6 SP - 1393-1401 LA - en OP - SN - 0046-225X 1938-2936 UR - http://dx.doi.org/10.1093/ee/nvaa112 DB - Crossref KW - Nosema ceranae KW - Crithidia bombi KW - Apis mellifera KW - Bombus impatiens KW - disease ER - TY - JOUR TI - Bumble bees are constant to nectar-robbing behaviour despite low switching costs AU - Lichtenberg, Elinor M. AU - Irwin, Rebecca E. AU - Bronstein, Judith L. T2 - ANIMAL BEHAVIOUR AB - Individuals sometimes exhibit striking constancy to a single behaviour even when they are capable of short-term behavioural flexibility. Constancy enables animals to avoid costs such as memory constraints, but can also inflict significant opportunity costs through behaviour–environment mismatch. It is unclear when individuals should exhibit behavioural constancy and which types of costs most strongly influence such behaviour. We use a case in which individuals within a population exhibit more than one handling tactic for a single food type to investigate whether costs associated with switching among tactics constrain expression of intra-individual variation. Using wild bumble bees (Bombus spp.) that feed on nectar through flower openings (legitimate visits) or through holes at the base of flowers (robbing), we asked three questions. (1) Do individual bees exhibit tactic constancy within and across foraging bouts? (2) Are individuals willing to switch their food-handling tactics? (3) Is constancy in food-handling tactics maintained by costs associated with switching tactics? We measured energetic costs in addition to handling times. We found that bees freely foraging in meadows were highly constant to a single food-handling tactic both within and across bouts. However, experiments with individual captive bees showed that these bees were willing to switch tactics and experienced minimal costs in doing so. Thus, switching costs do not drive the observed constancy in food-handling tactics of bumble bees within and across foraging bouts. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.anbehav.2020.09.008 VL - 170 SP - 177-188 SN - 1095-8282 KW - behavioural constancy KW - Bombus KW - costs KW - food handling KW - foraging KW - intra-individual variation (IIV) KW - mutualism KW - nectar robbing KW - planteanimal interaction KW - pollination ER - TY - JOUR TI - Towards a US national program for monitoring native bees AU - Woodard, S. Hollis AU - Federman, Sarah AU - James, Rosalind R. AU - Danforth, Bryan N. AU - Griswold, Terry L. AU - Inouye, David AU - McFrederick, Quinn S. AU - Morandin, Lora AU - Paul, Deborah L. AU - Sellers, Elizabeth AU - Strange, James P. AU - Vaughan, Mace AU - Williams, Neal M. AU - Branstetter, Michael G. AU - Burns, Casey T. AU - Cane, James AU - Cariveau, Alison B. AU - Cariveau, Daniel P. AU - Childers, Anna AU - Childers, Christopher AU - Cox-Foster, Diana L. AU - Evans, Elaine C. AU - Graham, Kelsey K. AU - Hackett, Kevin AU - Huntzinger, Kimberly T. AU - Irwin, Rebecca E. AU - Jha, Shalene AU - Lawson, Sarah AU - Liang, Christina AU - Lopez-Uribe, Margarita M. AU - Melathopoulos, Andony AU - Moylett, Heather M. C. AU - Otto, Clint R. V. AU - Ponisio, Lauren C. AU - Richardson, Leif L. AU - Rose, Robyn AU - Singh, Rajwinder AU - Wehling, Wayne T2 - BIOLOGICAL CONSERVATION AB - North America has more than 4000 bee species, yet we have little information on the health, distribution, and population trends of most of these species. In the United States, what information is available is distributed across multiple institutions, and efforts to track bee populations are largely uncoordinated on a national scale. An overarching framework for monitoring U.S. native bees could provide a system that is responsive to national needs, resources, and capacities. Five major action areas and priorities for structuring a coordinated effort include: (1) Defining the scope, aims, and cost of a national native bee monitoring program; (2) Improving the national capacity in bee taxonomy and systematics; (3) Gathering and cataloging data that are standardized, accessible, and sustainable; (4) Identifying survey methods and prioritizing taxa to monitor; and (5) Prioritizing geographic areas to be monitored. Here, we detail the needs, challenges, and opportunities associated with developing a multi-layered U.S. national plan for native bee monitoring. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.biocon.2020.108821 VL - 252 SP - SN - 1873-2917 KW - Pollinators KW - Monitoring KW - Native bees ER - TY - JOUR TI - Identifying Candidate Genetic Markers of CDV Cross-Species Pathogenicity in African Lions AU - Weckworth, Julie K. AU - Davis, Brian W. AU - Roelke-Parker, Melody E. AU - Wilkes, Rebecca P. AU - Packer, Craig AU - Eblate, Ernest AU - Schwartz, Michael K. AU - Mills, L. Scott T2 - PATHOGENS AB - Canine distemper virus (CDV) is a multi-host pathogen with variable clinical outcomes of infection across and within species. We used whole-genome sequencing (WGS) to search for viral markers correlated with clinical distemper in African lions. To identify candidate markers, we first documented single-nucleotide polymorphisms (SNPs) differentiating CDV strains associated with different clinical outcomes in lions in East Africa. We then conducted evolutionary analyses on WGS from all global CDV lineages to identify loci subject to selection. SNPs that both differentiated East African strains and were under selection were mapped to a phylogenetic tree representing global CDV diversity to assess if candidate markers correlated with documented outbreaks of clinical distemper in lions (n = 3). Of 54 SNPs differentiating East African strains, ten were under positive or episodic diversifying selection and 20 occurred in the clinical strain despite strong purifying selection at those loci. Candidate markers were in functional domains of the RNP complex (n = 19), the matrix protein (n = 4), on CDV glycoproteins (n = 5), and on the V protein (n = 1). We found mutations at two loci in common between sequences from three CDV outbreaks of clinical distemper in African lions; one in the signaling lymphocytic activation molecule receptor (SLAM)-binding region of the hemagglutinin protein and another in the catalytic center of phosphodiester bond formation on the large polymerase protein. These results suggest convergent evolution at these sites may have a functional role in clinical distemper outbreaks in African lions and uncover potential novel barriers to pathogenicity in this species. DA - 2020/11// PY - 2020/11// DO - 10.3390/pathogens9110872 VL - 9 IS - 11 SP - SN - 2076-0817 KW - canine distemper virus KW - African lion KW - cross-species pathogenicity KW - multi-host pathogen KW - evolutionary genetics KW - viral genomics KW - spillover ER - TY - JOUR TI - Colony-Level Effects of Amygdalin on Honeybees and Their Microbes AU - Tauber, James P. AU - Tozkar, Cansu Ö. AU - Schwarz, Ryan S. AU - Lopez, Dawn AU - Irwin, Rebecca E. AU - Adler, Lynn S. AU - Evans, Jay D. T2 - Insects AB - Amygdalin, a cyanogenic glycoside, is found in the nectar and pollen of almond trees, as well as in a variety of other crops, such as cherries, nectarines, apples and others. It is inevitable that western honeybees (Apis mellifera) consistently consume amygdalin during almond pollination season because almond crops are almost exclusively pollinated by honeybees. This study tests the effects of a field-relevant concentration of amygdalin on honeybee microbes and the activities of key honeybee genes. We executed a two-month field trial providing sucrose solutions with or without amygdalin ad libitum to free-flying honeybee colonies. We collected adult worker bees at four time points and used RNA sequencing technology and our HoloBee database to assess global changes in microbes and honeybee transcripts. Our hypothesis was that amygdalin will negatively affect bee microbes and possibly immune gene regulation. Using a log2 fold-change cutoff at two and intraday comparisons, we show no large change of bacterial counts, fungal counts or key bee immune gene transcripts, due to amygdalin treatment in relation to the control. However, relatively large titer decreases in the amygdalin treatment relative to the control were found for several viruses. Chronic bee paralysis virus levels had a sharp decrease (-14.4) with titers then remaining less than the control, Black queen cell virus titers were lower at three time points (<-2) and Deformed wing virus titers were lower at two time points (<-6) in amygdalin-fed compared to sucrose-fed colonies. Titers of Lotmaria passim were lower in the treatment group at three of the four dates (<-4). In contrast, Sacbrood virus had two dates with relative increases in its titers (>2). Overall, viral titers appeared to fluctuate more so than bacteria, as observed by highly inconstant patterns between treatment and control and throughout the season. Our results suggest that amygdalin consumption may reduce several honeybee viruses without affecting other microbes or colony-level expression of immune genes. DA - 2020/11/11/ PY - 2020/11/11/ DO - 10.3390/insects11110783 VL - 11 IS - 11 SP - 783 J2 - Insects LA - en OP - SN - 2075-4450 UR - http://dx.doi.org/10.3390/insects11110783 DB - Crossref ER - TY - JOUR TI - Foundation Species Abundance Influences Food Web Topology on Glass Sponge Reefs AU - Archer, Stephanie K. AU - Kahn, Amanda S. AU - Thiess, Mary AU - Law, Lauren AU - Leys, Sally P. AU - Johannessen, Sophia C. AU - Layman, Craig A. AU - Burke, Lily AU - Dunham, Anya T2 - FRONTIERS IN MARINE SCIENCE AB - Foundation species support communities across a wide range of ecosystems. Non-trophic interactions are considered the primary way foundation species influence communities, with their trophic interactions having little impact on community structure. Here we assess the relative trophic importance of a foundation species and assess how its abundance can influence food web topology. Using empirical data and published trophic interactions we built food web models for 20 glass sponge reefs to examine how average live reef-building sponge abundance (proxied by percent cover) at the reef level is correlated with community structure and food web network topology. Then, using a generalized food web model and stable isotope data we examined the relative importance of sponges. Sponges were consumed by all species examined and contributed significantly to their diets. Additionally, sponges were the second most important node in our generalized reef food web. Several metrics of food web topology (connectance, clustering, and median degree) and community structure exhibited a threshold response to reef-building sponge cover, with the change point occurring between 8 and 13% live sponge cover. Below this threshold, as average sponge cover increases, the consumers observed on a reef rely on fewer sources and are consumed by fewer predators, resulting in food webs that are more clustered and less connected. Above the threshold, as average sponge cover increases, the reefs’ food webs are less clustered and more connected, with consumers utilizing more sources and having more predators. This corresponds with the finding that several generalist predators (e.g., rockfishes) are associated with high sponge cover reefs. Our results are not consistent with previous reports that increasing foundation species abundance decreases connectance in food webs. We propose that the influence of foundation species on food web topology may be dependent on palatability, and therefore relative trophic importance, of the foundation species. Finally, our findings have important implications for sponge reef conservation and management, as they suggest that reefs below the 10% sponge cover threshold support different communities than high live sponge cover reefs. DA - 2020/// PY - 2020/// DO - 10.3389/fmars.2020.549478 VL - 7 ER - TY - ER - TY - JOUR TI - An ecosystem ecology perspective on artificial reef production AU - Layman, Craig A. AU - Allgeier, Jacob E. T2 - JOURNAL OF APPLIED ECOLOGY AB - Abstract Artificial reefs are used around the world for many purposes, including widespread deployment to increase fishery yields. These reefs are well‐studied from a direct fisheries‐based perspective, drawing largely on traditional theory and methodological approaches from population and community ecology. Here we provide an alternative perspective using basic tenets of ecosystem ecology. We focus largely on primary production, as this ecosystem process necessarily constrains the secondary production of fish and invertebrates. We use this ecosystem ecology viewpoint to examine the long‐standing attraction/production question—do artificial reefs support ‘new’ fish production or simply attract individuals from other habitats? Central to this discussion is identifying ecological thresholds and self‐reinforcing feedbacks. For example, biological or physical processes may facilitate reaching nutrient supply thresholds where fundamental ecological dynamics are shifted, such as enhanced seagrass allocation of resources to above‐ground plant structures following aggregation of fish around reefs. Synthesis and applications . We propose that the scope for enhanced primary productivity (or other accelerated ecosystem processes) is an under‐utilized guideline that can be used to prioritize artificial reef deployment as part of broader coastal management programmes. Such an ecosystem ecology perspective may provide new insights into the ecological role of artificial reefs and guide the optimization of their deployment and management. DA - 2020/11// PY - 2020/11// DO - 10.1111/1365-2664.13748 VL - 57 IS - 11 SP - 2139-2148 SN - 1365-2664 KW - artificial reef production KW - decomposition KW - food webs KW - marine fisheries KW - nutrients KW - primary production KW - reefs KW - threshold effects ER - TY - JOUR TI - Cross-infectivity of honey and bumble bee-associated parasites across three bee families AU - Ngor, Lyna AU - Palmer-Young, Evan C. AU - Burciaga Nevarez, Rodrigo AU - Russell, Kaleigh A. AU - Leger, Laura AU - Giacomini, Sara June AU - Pinilla-Gallego, Mario S. AU - Irwin, Rebecca E. AU - McFrederick, Quinn S. T2 - Parasitology AB - Recent declines of wild pollinators and infections in honey, bumble and other bee species have raised concerns about pathogen spillover from managed honey and bumble bees to other pollinators. Parasites of honey and bumble bees include trypanosomatids and microsporidia that often exhibit low host specificity, suggesting potential for spillover to co-occurring bees via shared floral resources. However, experimental tests of trypanosomatid and microsporidial cross-infectivity outside of managed honey and bumble bees are scarce. To characterize potential cross-infectivity of honey and bumble bee-associated parasites, we inoculated three trypanosomatids and one microsporidian into five potential hosts - including four managed species - from the apid, halictid and megachilid bee families. We found evidence of cross-infection by the trypanosomatids Crithidia bombi and C. mellificae, with evidence for replication in 3/5 and 3/4 host species, respectively. These include the first reports of experimental C. bombi infection in Megachile rotundata and Osmia lignaria, and C. mellificae infection in O. lignaria and Halictus ligatus. Although inability to control amounts inoculated in O. lignaria and H. ligatus hindered estimates of parasite replication, our findings suggest a broad host range in these trypanosomatids, and underscore the need to quantify disease-mediated threats of managed social bees to sympatric pollinators. DA - 2020/6/18/ PY - 2020/6/18/ DO - 10.1017/S0031182020001018 VL - 147 IS - 12 SP - 1290-1304 J2 - Parasitology LA - en OP - SN - 0031-1820 1469-8161 UR - http://dx.doi.org/10.1017/S0031182020001018 DB - Crossref KW - Alfalfa leafcutter bee KW - blue orchard bee KW - flagellate KW - Halictus ligatus KW - host-parasite specificity KW - Kinetoplastidae KW - Leishmaniiniae KW - Megachile rotundata KW - Osmia lignaria KW - sweat bee ER - TY - JOUR TI - Bee phenology is predicted by climatic variation and functional traits AU - Stemkovski, Michael AU - Pearse, William D. AU - Griffin, Sean R. AU - Pardee, Gabriella L. AU - Gibbs, Jason AU - Griswold, Terry AU - Neff, John L. AU - Oram, Ryan AU - Rightmyer, Molly G. AU - Sheffield, Cory S. AU - Wright, Karen AU - Inouye, Brian D. AU - Inouye, David W. AU - Irwin, Rebecca E. T2 - Ecology Letters AB - Abstract Climate change is shifting the environmental cues that determine the phenology of interacting species. Plant–pollinator systems may be susceptible to temporal mismatch if bees and flowering plants differ in their phenological responses to warming temperatures. While the cues that trigger flowering are well‐understood, little is known about what determines bee phenology. Using generalised additive models, we analyzed time‐series data representing 67 bee species collected over 9 years in the Colorado Rocky Mountains to perform the first community‐wide quantification of the drivers of bee phenology. Bee emergence was sensitive to climatic variation, advancing with earlier snowmelt timing, whereas later phenophases were best explained by functional traits including overwintering stage and nest location. Comparison of these findings to a long‐term flower study showed that bee phenology is less sensitive than flower phenology to climatic variation, indicating potential for reduced synchrony of flowers and pollinators under climate change. DA - 2020/8/19/ PY - 2020/8/19/ DO - 10.1111/ele.13583 VL - 23 IS - 11 SP - 1589-1598 J2 - Ecology Letters LA - en OP - SN - 1461-023X 1461-0248 UR - http://dx.doi.org/10.1111/ele.13583 DB - Crossref KW - Climate change KW - emergence KW - environmental cues KW - GAM (generalised additive models) KW - Hymenoptera KW - mismatch KW - peak KW - phenophases KW - senescence ER - TY - JOUR TI - Taxonomic identity best explains variation in body nutrient stoichiometry in a diverse marine animal community AU - Allgeier, Jacob E. AU - Wenger, Seth AU - Layman, Craig A. T2 - SCIENTIFIC REPORTS AB - Abstract Animal-mediated nutrient dynamics are critical processes in ecosystems. Previous research has found animal-mediated nutrient supply (excretion) to be highly predictable based on allometric scaling, but similar efforts to find universal predictive relationships for an organism’s body nutrient content have been inconclusive. We use a large dataset from a diverse tropical marine community to test three frameworks for predicting body nutrient content. We show that body nutrient content does not follow allometric scaling laws and that it is not well explained by trophic status. Instead, we find strong support for taxonomic identity (particularly at the family level) as a predictor of body nutrient content, indicating that evolutionary history plays a crucial role in determining an organism’s composition. We further find that nutrients are “stoichiometrically linked” (e.g., %C predicts %N), but that the direction of these relationships does not always conform to expectations, especially for invertebrates. Our findings demonstrate that taxonomic identity, not trophic status or body size, is the best baseline from which to predict organismal body nutrient content. DA - 2020/8/13/ PY - 2020/8/13/ DO - 10.1038/s41598-020-67881-y VL - 10 IS - 1 SP - SN - 2045-2322 ER - TY - JOUR TI - Preserving connectivity under climate and land-use change: No one-size-fits-all approach for focal species in similar habitats AU - Costanza, Jennifer K. AU - Watling, James AU - Sutherland, Ron AU - Belyea, Curtis AU - Dilkina, Bistra AU - Cayton, Heather AU - Bucklin, David AU - Romanach, Stephanie S. AU - Haddad, Nick M. T2 - BIOLOGICAL CONSERVATION AB - Habitat connectivity is essential for maintaining populations of wildlife species, especially as climate changes. Knowledge about the fate of existing habitat networks in a changing climate and in light of land-use change is critical for determining which types of conservation actions must be taken to maintain those networks. However, information is lacking about how multiple focal species that use similar habitats overlap in the degree and geographic patterns of threats to linkages among currently suitable habitat patches. We sought to address that gap. We assessed climate change threat to existing linkages in the southeastern United States for three wildlife species that use similar habitats but differ in the degree to which their ranges are limited by climate, habitat specificity, and dispersal ability. Linkages for the specialist species (timber rattlesnake), whose range is climate-restricted, were more likely to serve as climate change refugia – that is, they were more likely to be climate-stable – by the middle of the 21st century. This contrasts with the two more generalist species (Rafinesque's big-eared bat and American black bear), whose linkages were threatened by climate change and thus required adaptation measures. Further incorporation of projected land-use change and current protection status for important linkages narrows down our recommended conservation actions for each species. Our results highlight the surprising ways in which even species that use similar habitats will experience differences in the degree and geographic patterns of threats to connectivity. Taking action before these projected changes occur will be critical for successful conservation. DA - 2020/8// PY - 2020/8// DO - 10.1016/j.biocon.2020.108678 VL - 248 SP - SN - 1873-2917 KW - Climate adaptation KW - Climate refugia KW - Corridor KW - Land-use change KW - Landscape conservation KW - Protection status ER - TY - JOUR TI - Snow-mediated plasticity does not prevent camouflage mismatch AU - Kumar, Alexander V AU - Zimova, Marketa AU - Sparks, James R. AU - Mills, L. Scott T2 - OECOLOGIA AB - Global reduction in snow cover duration is one of the most consistent and widespread climate change outcomes. Declining snow duration has severe negative consequences for diverse taxa including seasonally color molting species, which rely on snow for camouflage. However, phenotypic plasticity may facilitate adaptation to reduced snow duration. Plastic responses could occur in the color molt phenology or through behavior that minimizes coat color mismatch or its consequences. We quantified molt phenology of 200 wild snowshoe hares (Lepus americanus), and measured microhabitat choice and local snow cover. Similar to other studies, we found that hares did not show behavioral plasticity to minimize coat color mismatch via background matching; instead they preferred colder, snow free areas regardless of their coat color. Furthermore, hares did not behaviorally mitigate the negative consequences of mismatch by choosing resting sites with denser vegetation cover when mismatched. Importantly, we demonstrated plasticity in the initiation and the rate of the molt and established the direct effect of snow on molt phenology; greater snow cover was associated with whiter hares and this association was not due to whiter hares preferring snowier areas. However, despite the observed snow-mediated plasticity in molt phenology, camouflage mismatch with white hares on brown snowless ground persisted and was more frequent during early snowmelt. Thus, we find no evidence that phenotypic plasticity in snowshoe hares is sufficient to facilitate adaptive rescue to camouflage mismatch under climate change. DA - 2020/11// PY - 2020/11// DO - 10.1007/s00442-020-04680-2 VL - 194 IS - 3 SP - 301-310 SN - 1432-1939 KW - Adaptive rescue KW - Phenotypic plasticity KW - Behavioral plasticity KW - Climate change KW - Molt phenology ER - TY - JOUR TI - Rewiring coral: Anthropogenic nutrients shift diverse coral-symbiont nutrient and carbon interactions toward symbiotic algal dominance AU - Allgeier, Jacob E. AU - Andskog, Mona A. AU - Hensel, Enie AU - Appaldo, Richard AU - Layman, Craig AU - Kemp, Dustin W. T2 - GLOBAL CHANGE BIOLOGY AB - Abstract Improving coral reef conservation requires heightened understanding of the mechanisms by which coral cope with changing environmental conditions to maintain optimal health. We used a long‐term (10 month) in situ experiment with two phylogenetically diverse scleractinians ( Acropora palmata and Porites porites ) to test how coral–symbiotic algal interactions changed under real‐world conditions that were a priori expected to be beneficial (fish‐mediated nutrients) and to be harmful, but non‐lethal, for coral (fish + anthropogenic nutrients). Analyzing nine response variables of nutrient stoichiometry and stable isotopes per coral fragment, we found that nutrients from fish positively affected coral growth, and moderate doses of anthropogenic nutrients had no additional effects. While growing, coral maintained homeostasis in their nutrient pools, showing tolerance to the different nutrient regimes. Nonetheless, structural equation models revealed more nuanced relationships, showing that anthropogenic nutrients reduced the diversity of coral–symbiotic algal interactions and caused nutrient and carbon flow to be dominated by the symbiont. Our findings show that nutrient and carbon pathways are fundamentally “rewired” under anthropogenic nutrient regimes in ways that could increase corals’ susceptibility to further stressors. We hypothesize that our experiment captured coral in a previously unrecognized transition state between mutualism and antagonism. These findings highlight a notable parallel between how anthropogenic nutrients promote symbiont dominance with the holobiont, and how they promote macroalgal dominance at the coral reef scale. Our findings suggest more realistic experimental conditions, including studies across gradients of anthropogenic nutrient enrichment as well as the incorporation of varied nutrient and energy pathways, may facilitate conservation efforts to mitigate coral loss. DA - 2020/10// PY - 2020/10// DO - 10.1111/gcb.15230 VL - 26 IS - 10 SP - 5588-5601 SN - 1365-2486 KW - coral reefs KW - eutrophication KW - fish nutrient supply KW - marine conservation KW - nitrogen KW - phase shift KW - phosphorus KW - Symbiodiniaceae KW - symbiosis ER - TY - JOUR TI - Sunflower pollen reduces a gut pathogen in worker and queen but not male bumble bees AU - Fowler, Alison E. AU - Stone, Elyse C. AU - Irwin, Rebecca E. AU - Adler, Lynn S. T2 - Ecological Entomology AB - 1. Social insect castes and sexes differ in many ways, including morphology, behavior, and sometimes ploidy level. Recent studies have found that consuming sunflower pollen reduces the gut pathogen Crithidia bombi in workers of the common eastern bumble bee ( Bombus impatiens ). Here, this work is extended to the reproductive individuals that represent colony fitness – males and queens – to assess if the medicinal effects of sunflower pollen vary with bee caste and sex. 2. This study examined the effect of sunflower pollen compared to a diverse wildflower pollen mix on infection in worker, male, and daughter queen commercial B . impatiens . Bees were infected, fed either sunflower pollen or wildflower pollen for 7 days, and then infection levels were assessed. 3. Compared to wildflower pollen, sunflower pollen dramatically reduced Crithidia infection in workers and daughter queens, but not males. Infection levels were very low for both diets in males; this could be due to low pollen consumption or other mechanisms. 4. Reducing Crithidia infection in young queens before they undergo hibernation is important for population dynamics since infected queens are less likely to survive hibernation, and those that do are less likely to successfully establish a nest the following spring. Because sunflowers bloom in late summer when new queens are emerging, sunflowers could provide an important dietary component for queens during this critical life stage. Deepening our understanding of how diet impacts pathogens in reproductive bees, as well as workers, is crucial to maintain healthy pollinator populations. DA - 2020/7/15/ PY - 2020/7/15/ DO - 10.1111/een.12915 VL - 45 IS - 6 SP - 1318-1326 J2 - Ecological Entomology LA - en OP - SN - 0307-6946 1365-2311 UR - http://dx.doi.org/10.1111/een.12915 DB - Crossref KW - Bombus impatiens KW - Crithidia KW - diet KW - pathogen resistance KW - pollinator KW - social caste ER - TY - JOUR TI - Parasite defense mechanisms in bees: behavior, immunity, antimicrobials, and symbionts AU - Fowler, Alison E. AU - Irwin, Rebecca E. AU - Adler, Lynn S. T2 - EMERGING TOPICS IN LIFE SCIENCES AB - Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management. DA - 2020/7// PY - 2020/7// DO - 10.1042/ETLS20190069 VL - 4 IS - 1 SP - 59-76 SN - 2397-8562 ER - TY - JOUR TI - Flowering plant composition shapes pathogen infection intensity and reproduction in bumble bee colonies AU - Adler, Lynn S. AU - Barber, Nicholas A. AU - Biller, Olivia M. AU - Irwin, Rebecca E. T2 - Proceedings of the National Academy of Sciences AB - Pathogens pose significant threats to pollinator health and food security. Pollinators can transmit diseases during foraging, but the consequences of plant species composition for infection is unknown. In agroecosystems, flowering strips or hedgerows are often used to augment pollinator habitat. We used canola as a focal crop in tents and manipulated flowering strip composition using plant species we had previously shown to result in higher or lower bee infection in short-term trials. We also manipulated initial colony infection to assess impacts on foraging behavior. Flowering strips using high-infection plant species nearly doubled bumble bee colony infection intensity compared to low-infection plant species, with intermediate infection in canola-only tents. Both infection treatment and flowering strips reduced visits to canola, but we saw no evidence that infection treatment shifted foraging preferences. Although high-infection flowering strips increased colony infection intensity, colony reproduction was improved with any flowering strips compared to canola alone. Effects of flowering strips on colony reproduction were explained by nectar availability, but effects of flowering strips on infection intensity were not. Thus, flowering strips benefited colony reproduction by adding floral resources, but certain plant species also come with a risk of increased pathogen infection intensity. DA - 2020/5/11/ PY - 2020/5/11/ DO - 10.1073/pnas.2000074117 VL - 117 IS - 21 SP - 11559-11565 J2 - Proc. Natl. Acad. Sci. U.S.A. LA - en OP - SN - 0027-8424 1091-6490 UR - http://dx.doi.org/10.1073/pnas.2000074117 DB - Crossref KW - hedgerows KW - pathogen transmission KW - pollinator decline KW - pollinator habitat KW - wildflower strips ER - TY - JOUR TI - Support early-career field researchers AU - Inouye, David W. AU - Underwood, Nora AU - Inouye, Brian D. AU - Irwin, Rebecca E. T2 - Science AB - Pandemic-induced restrictions on research are now ubiquitous. We urge administrators and policy-makers to recognize that field researchers—especially those early in their careers—face unique challenges, even if restrictions last only a month or two. Bans on travel, hiring, and facility use are forcing many researchers to abandon the entire field season, losing a full year of irreplaceable data and research-training opportunities. The loss of data is most damaging for multi-year projects, which are common in the case of field research. For example, a lost year in a demographic study renders multiple years of data uninterpretable because data on growth and survival between years are required for analysis. Similarly, in any system with lagging effects, the loss of a single season can have multi-year consequences on analyses. For long-term studies, the loss of a single year may seem less damaging, but increasing climate variance means that each season brings new insights. The impact of lost research is most severe for scientists at early career stages. Institutions and agencies should focus on protecting graduate students and postdocs, as the loss of a year's data can affect their ability to complete dissertations or acquire jobs. We call on policy-makers and institutions to provide funding opportunities for early-career researchers to recover from such disruptions; support for salary, stipends, and tuition will be most critical. Although scientists conducting field research may be most vulnerable, these funding opportunities would certainly benefit laboratory-based scientists as well. No one institution or agency has the resources to prevent impacts of lost research on field science or science in general. However, modest targeted funding for the most vulnerable research projects and researchers would help to preserve the quality of research and the pipeline of research training that we depend on for our next generation of scientists. DA - 2020/5/15/ PY - 2020/5/15/ DO - 10.1126/science.abc1261 VL - 368 IS - 6492 SP - 724-725 J2 - Science LA - en OP - SN - 0036-8075 1095-9203 UR - http://dx.doi.org/10.1126/science.abc1261 DB - Crossref ER - TY - JOUR TI - Cross-species transmission and evolutionary dynamics of canine distemper virus during a spillover in African lions of Serengeti National Park AU - Weckworth, Julie K. AU - Davis, Brian W. AU - Dubovi, Edward AU - Fountain-Jones, Nicholas AU - Packer, Craig AU - Cleaveland, Sarah AU - Craft, Meggan E. AU - Eblate, Ernest AU - Schwartz, Michael AU - Mills, L. Scott AU - Roelke-Parker, Melody T2 - MOLECULAR ECOLOGY AB - Abstract The outcome of pathogen spillover from a reservoir to a novel host population can range from a “dead‐end” when there is no onward transmission in the recipient population, to epidemic spread and even establishment in new hosts. Understanding the evolutionary epidemiology of spillover events leading to discrete outcomes in novel hosts is key to predicting risk and can lead to a better understanding of the mechanisms of emergence. Here we use a Bayesian phylodynamic approach to examine cross‐species transmission and evolutionary dynamics during a canine distemper virus (CDV) spillover event causing clinical disease and population decline in an African lion population ( Panthera leo ) in the Serengeti Ecological Region between 1993 and 1994. Using 21 near‐complete viral genomes from four species we found that this large‐scale outbreak was likely ignited by a single cross‐species spillover event from a canid reservoir to noncanid hosts <1 year before disease detection and explosive spread of CDV in lions. Cross‐species transmission from other noncanid species probably fuelled the high prevalence of CDV across spatially structured lion prides. Multiple lines of evidence suggest that spotted hyenas ( Crocuta crocuta ) could have acted as the proximate source of CDV exposure in lions. We report 13 nucleotide substitutions segregating CDV strains found in canids and noncanids. Our results are consistent with the hypothesis that virus evolution played a role in CDV emergence in noncanid hosts following spillover during the outbreak, suggest that host barriers to clinical infection can limit outcomes of CDV spillover in novel host species. DA - 2020/11// PY - 2020/11// DO - 10.1111/mec.15449 VL - 29 IS - 22 SP - 4308-4321 SN - 1365-294X KW - African lion KW - canine distemper virus KW - carnivore conservation KW - evolutionary epidemiology KW - pathogen spillover KW - Serengeti ER - TY - JOUR TI - The role of multiple stressors in a dwarf red mangrove (Rhizophora mangle) dieback AU - Rossi, R. E. AU - Archer, S. K. AU - Giri, C. AU - Layman, C. A. T2 - ESTUARINE COASTAL AND SHELF SCIENCE AB - Mangroves are habitat-forming foundation species that provide the framework for entire coastal communities. Unfortunately, mangrove forests are declining globally, often due to multiple stressors. We report a recent mangrove dieback on Abaco Island, The Bahamas, that appears to be the result of multiple stressors. First, we investigated the role of hurricane and drought events in relation to green vegetation in the dieback area, as measured using Normalized Difference Vegetation Index (NDVI). We used historical Landsat imagery of the dieback region from 1989 to 2013 to identify changes in green vegetation and to determine when the dieback likely began. We determined that the dieback began around 2008, but found little evidence of a relationship between NDVI and hurricane or drought events, particularly in relation to the estimated start of the dieback. Preliminary observations in the dieback area suggested grazing by leaf-chewing organisms and disease were both present at high levels. We surveyed individual mangrove trees to determine the intensity of leaf-chewing herbivory and foliar disease on mangroves in the dieback area. We found leaf-chewing herbivory ranged from 0 to 79%, with a mean of 29% of leaves chewed per tree and disease incidence ranged from 0% to 97% with a mean of 47%. Finally, we conducted a simulated grazing experiment to test if experimental opening mimicking grazing could facilitate disease infection in mangroves . Experimental opening of plant tissues showed that grazing can increase disease. Our results suggest that drought and hurricanes did not initiate this dieback, but that herbivory likely facilitated the spread of disease thereby contributing to the dieback. DA - 2020/5/31/ PY - 2020/5/31/ DO - 10.1016/j.ecss.2020.106660 VL - 237 SP - SN - 1096-0015 KW - Drought KW - Disease KW - Herbivory KW - Hurricane KW - Multiple stressors ER - TY - JOUR TI - Competition for nectar resources does not affect bee foraging tactic constancy AU - Lichtenberg, Elinor M. AU - Richman, Sarah K. AU - Irwin, Rebecca E. AU - Bronstein, Judith L. T2 - Ecological Entomology AB - 1. Competition alters animal foraging, including promoting the use of alternative resources. It may also impact how animals feed when they are able to handle the same food with more than one tactic. Competition likely impacts both consumers and their resources through its effects on food handling, but this topic has received little attention. 2. Bees often use two tactics for extracting nectar from flowers: they can visit at the flower opening, or rob nectar from holes at the base of flowers. Exploitative competition for nectar is thought to promote nectar robbing. If so, higher competition among floral visitors should reduce constancy to a single foraging tactic as foragers will seek food using all possible tactics. To test this prediction, field observations and two experiments involving bumble bees visiting three montane Colorado plant species ( Mertensia ciliata , Linaria vulgaris , Corydalis caseana ) were used under various levels of inter‐ and intra‐specific competition for nectar. 3. In general, individual bumble bees remained constant to a single foraging tactic, independent of competition levels. However, bees that visited M. ciliata in field observations decreased their constancy and increased nectar robbing rates as visitation rates by co‐visitors increased. 4. While tactic constancy was high overall regardless of competition intensity, this study highlights some intriguing instances in which competition and tactic constancy may be linked. Further studies investigating the cognitive underpinnings of tactic constancy should provide insight on the ways in which animals use alternative foraging tactics to exploit resources. DA - 2020/3/30/ PY - 2020/3/30/ DO - 10.1111/een.12866 VL - 45 IS - 4 SP - 904-909 J2 - Ecological Entomology LA - en OP - SN - 0307-6946 1365-2311 UR - http://dx.doi.org/10.1111/een.12866 DB - Crossref KW - Bombus KW - food handling KW - foraging KW - mutualism KW - nectar robbing KW - pollination ER - TY - JOUR TI - Assessing Chemical Mechanisms Underlying the Effects of Sunflower Pollen on a Gut Pathogen in Bumble Bees AU - Adler, Lynn S. AU - Fowler, Alison E. AU - Malfi, Rosemary L. AU - Anderson, Patrick R. AU - Coppinger, Lily M. AU - Deneen, Pheobe M. AU - Lopez, Stephanie AU - Irwin, Rebecca E. AU - Farrell, Iain W. AU - Stevenson, Philip C. T2 - Journal of Chemical Ecology AB - Many pollinator species are declining due to a variety of interacting stressors including pathogens, sparking interest in understanding factors that could mitigate these outcomes. Diet can affect host-pathogen interactions by changing nutritional reserves or providing bioactive secondary chemicals. Recent work found that sunflower pollen (Helianthus annuus) dramatically reduced cell counts of the gut pathogen Crithidia bombi in bumble bee workers (Bombus impatiens), but the mechanism underlying this effect is unknown. Here we analyzed methanolic extracts of sunflower pollen by LC-MS and identified triscoumaroyl spermidines as the major secondary metabolite components, along with a flavonoid quercetin-3-O-hexoside and a quercetin-3-O-(6-O-malonyl)-hexoside. We then tested the effect of triscoumaroyl spermidine and rutin (as a proxy for quercetin glycosides) on Crithidia infection in B. impatiens, compared to buckwheat pollen (Fagopyrum esculentum) as a negative control and sunflower pollen as a positive control. In addition, we tested the effect of nine fatty acids from sunflower pollen individually and in combination using similar methods. Although sunflower pollen consistently reduced Crithidia relative to control pollen, none of the compounds we tested had significant effects. In addition, diet treatments did not affect mortality, or sucrose or pollen consumption. Thus, the mechanisms underlying the medicinal effect of sunflower are still unknown; future work could use bioactivity-guided fractionation to more efficiently target compounds of interest, and explore non-chemical mechanisms. Ultimately, identifying the mechanism underlying the effect of sunflower pollen on pathogens will open up new avenues for managing bee health. DA - 2020/3/23/ PY - 2020/3/23/ DO - 10.1007/s10886-020-01168-4 VL - 46 IS - 8 SP - 649-658 J2 - J Chem Ecol LA - en OP - SN - 0098-0331 1573-1561 UR - http://dx.doi.org/10.1007/s10886-020-01168-4 DB - Crossref KW - Bee pathogens KW - Bombus impatiens KW - Crithidia bombi KW - Helianthus annuus KW - Pollen chemistry KW - Pollinator health ER - TY - JOUR TI - Individual behavior drives ecosystem function and the impacts of harvest AU - Allgeier, Jacob E. AU - Cline, Timothy J. AU - Walsworth, Timothy E. AU - Wathen, Gus AU - Layman, Craig A. AU - Schindler, Daniel E. T2 - SCIENCE ADVANCES AB - Current approaches for biodiversity conservation and management focus on sustaining high levels of diversity among species to maintain ecosystem function. We show that the diversity among individuals within a single population drives function at the ecosystem scale. Specifically, nutrient supply from individual fish differs from the population average >80% of the time, and accounting for this individual variation nearly doubles estimates of nutrients supplied to the ecosystem. We test how management (i.e., selective harvest regimes) can alter ecosystem function and find that strategies targeting more active individuals reduce nutrient supply to the ecosystem up to 69%, a greater effect than body size-selective or nonselective harvest. Findings show that movement behavior at the scale of the individual can have crucial repercussions for the functioning of an entire ecosystem, proving an important challenge to the species-centric definition of biodiversity if the conservation and management of ecosystem function is a primary goal. DA - 2020/2// PY - 2020/2// DO - 10.1126/sciadv.aax8329 VL - 6 IS - 9 SP - SN - 2375-2548 ER -