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What causes host-use specificity in herbivorous insects? Population genetic models predict specialization when habitat preference can evolve and there is antagonistic pleiotropy at a performance-affecting locus. But empirically for herbivorous insects, host-use performance is governed by many genetic loci, and antagonistic pleiotropy seems to be rare. Here, we use individual-based quantitative genetic simulation models to investigate the role of pleiotropy in the evolution of sympatric host-use specialization when performance and preference are quantitative traits. We look first at pleiotropies affecting only host-use performance. We find that when the host environment changes slowly the evolution of host-use specialization requires levels of antagonistic pleiotropy much higher than what has been observed in nature. On the other hand, with rapid environmental change or pronounced asymmetries in productivity across host species, the evolution of host-use specialization readily occurs without pleiotropy. When pleiotropies affect preference as well as performance, even with slow environmental change and host species of equal productivity, we observe fluctuations in host-use breadth, with mean specificity increasing with the pervasiveness of antagonistic pleiotropy. So, our simulations show that pleiotropy is not necessary for specialization, although it can be sufficient, provided it is extensive or multifarious.

There is a little understanding of how apex carnivores partition their diet to coexist. We studied food habit and trophic niche overlap of two apex carnivores, tiger and leopard in the tropical forest of Similipal tiger reserve, eastern India. We used line transect and scat analysis method, to estimate the prey availability and determine the diet and prey selection of two apex carnivores. Tigers consumed mostly large and medium-sized prey, whereas leopards mostly consumed medium and small-sized prey. Both carnivores were not random in their consumption of prey, sambar and wild pigs were selectively consumed by tigers, whereas leopards selectively consumed wild pigs, barking deer and mouse deer. Dietary overlap between two carnivore species was moderate (Pianka's niche overlap index: 0.55), and trophic niche breadth (Levin's standardized niche breadth) of the leopard (0.52) was greater than that of the tiger (0.37). Overall, tigers exhibited specialized feeding habits, whereas leopards showed generalist feeding habits. Our study highlights the opportunistic nature of leopards and probably a reason for the species successfully coexist with tigers.

Urban expansions into natural habitats have forced many carnivores to adapt to the modified areas; however, our understanding of their ecology in such areas is limited. The Indian fox (Vulpes bengalensis) is a small carnivore species that can adapt and exploit urban areas due to its generalist nature, but there is a paucity of data on Indian foxes in these human-modified areas. To understand the resource requirement of Indian foxes in urban habitats, we conducted a diet analysis by examining 119 scats of Indian foxes in a peri-urban habitat of Baripada town, Odisha, eastern India. To determine the diet composition of Indian foxes, we analyzed scat contents by their frequency occurrence (%FO), the relative frequency of occurrence (%RF) and mean percent volume (%Vm). Indian foxes consumed a wide range of food categories, including arthropods, rodents, reptiles, birds, plant parts and anthropogenic resources. In %Vm, rodents showed the highest volume, followed by polythene, Spondias pinnata fruit and Coleoptera. We found anthropogenic foods in considerable quantities, including polythene and paper. The diet of Indian foxes indicates that the species has opportunistic and generalist feeding habits consisting primarily of easily accessible foods. Furthermore, management efforts should focus on the proper management of waste and control of anthropogenic food sources in urban habitats.

El estudio de las redes de interacción mutualista es fundamental porque permite conocer las especies que se relacionan al considerar los análisis de sus dietas y al evaluar el efecto de las perturbaciones de un ecosistema. Para una reserva es importante reconocer estos fenómenos, pues evidencian si los esfuerzos de conservación han sido efectivos. Este trabajo se desarrolló en los años 2014 y 2017 en la vereda Playa Güío del municipio de San José el Guaviare, Colombia. Para conocer la amplitud del nicho y el solapamiento de dietas se calculó el índice de Levins y el índice de Morisita respectivamente. Usando la modularidad, la robustez y el anidamiento (NODF), se analizaron las redes de interacción. Se registraron 18 especies de murciélagos frugívoros y 20 especies de plantas pertenecientes a las familias Piperaceae, Urticaceae, Moraceae, Hypericaceae y Solanaceae. El índice de Levins demostró que las especies de murciélagos prefieren un recurso, mientras que el índice de Morisita evidencia un traslape en las especies frugívoras nómadas y las sedentarias. El anidamiento y la robustez disminuyeron en 2017 ya que aumentó el número de especies, mientras que la modularidad aumentó. La vereda Playa Güío mantiene una red de interacción con especies generalistas asociadas a procesos de regeneración natural importantes para los objetivos de conservación de la reserva, además, las métricas calculadas indican que esta red de interacción mutualista es estable y se puede mantener en el tiempo.

Microbial growth under extreme conditions is often slow. This is partly because large amounts of energy are diverted into cellular mechanisms that allow survival under hostile conditions. Because this challenge is universal and diversity in extreme environments is low compared to non-extreme environments, slow-growing microorganisms are not overgrown by other species. In some cases, especially when nutrients are scarce, slow growth was even shown to increase stress tolerance. And in at least some species of extremotolerant and extremophilic fungi, growth rate appears to be coupled with their very unusual morphologies, which in turn may be an adaptation to extreme conditions. However, there is more than one strategy of survival in extreme environments. Fungi that thrive in extremes can be divided into (i) ubiquitous and polyextremotolerant generalists and (ii) rarely isolated specialists with narrow ecological amplitudes. While generalists can compete with mesophilic species, specialists cannot. When adapting to extreme conditions, the risk of an evolutionary trade-off in the form of reduced fitness under mesophilic conditions may limit the maximum stress tolerance achievable by polyextremotolerant generalists. At the same time, specialists are rarely found in mesophilic environments, which allows them to evolve to ever greater extremotolerance, since a reduction of mesophilic fitness is likely to have little impact on their evolutionary success.

Species differing in life-history attributes vary in their responses to features within a shared landscape. We evaluated genetic structure of sympatric gartersnake species in southwestern Ontario (Canada) and southeastern Michigan (USA), where habitat fragmentation is high due to agriculture and urbanization. We surveyed genetic structure of a habitat specialist, Butler’s Gartersnake (Thamnophis butleri (Cope, 1889)), and a habitat generalist, Eastern Gartersnake (Thamnophis sirtalis sirtalis (Linnaeus, 1758)), using DNA microsatellites. Bayesian clustering, discriminant analysis of principal components, and pairwise population comparisons revealed genetic differentiation among three major regional clusters of Butler’s Gartersnake with evidence of further division within one. Genetic clustering of Butler’s Gartersnake suggest that inhospitable habitat limits dispersal. Eastern Gartersnakes showed less structure, with assignment tests implying a single genetic cluster. We found positive significant Mantel’s r for both species in the smallest distance class (

Aloe reitzii var. reitzii is a summer-flowering (February–March) succulent, endemic to a restricted range within the heavily transformed grasslands of eastern South Africa. Floral structure and nectar properties suggest bird-pollination. This study investigated the temporal visitation events of birds to this aloe. Extensive camera observations during the 2017 flowering season (23 days) identified both specialist and generalist nectarivorous birds (n = four and five species respectively) as regular diurnal aloe visitors. Malachite Sunbirds (Nectarinia famosa) accounted for 49% of all visits, while Cape Weavers (Ploceus capensis) made up 41% of all visits; these species co-dominate visitation of the specialist and generalist avian feeding guilds respectively. In addition, visitation by each guild was separated temporally to some extent, with generalists mostly visiting early in the day, while specialists dominate afternoon visitation. Nectar volume (overall unbagged mean = 48.67 ± 4.70 µL) and concentration (overall unbagged mean = 10.68 ± 0.21% w/w) remains consistent throughout the day, and are within generalist nectar-feeding bird preferences, which may explain the abundance of Cape Weavers, despite floral morphological traits matching those of specialist nectar feeders. While many summer-flowering aloes are primarily insect- or sunbird-pollinated, Cape Weavers may be supplementing their diets with A. reitzii var. reitzii nectar, and potentially playing a crucial role in pollination.

Urbanization represents one of the most striking threats to biodiversity due to habitat loss and fragmentation, particularly in forest biomes. The role of the surrounding matrix in maintaining native diversity in urban areas remains poorly studied. We compared taxonomic and functional bird diversity and dissimilarity between urban settlements (USs) and natural habitats (NHs) in the forest landscape matrix (FM) and agriculture landscape matrix (AM) of the Atlantic Forest of South America, and explored the relationships of species traits between USs and NHs. Birds were surveyed in five USs and five NHs in the FM, and four USs and three NHs in the AM using point counts. We used generalized least squares models to test for differences in diversities and dissimilarities between sites from the two landscapes, and the similarity percentage and fourth-corner analysis to determine the bird species and traits that contributed most to the differences between habitat types. Taxonomic and functional diversities were higher and dissimilarities were lower for US in the FM than for those in the AM. Species with urban and generalist traits occurred in all USs, but assemblages also included forest species in the FM. Urban areas should be managed to maintain a forest component, provided that it is necessary for forest bird species to breed successfully.

Increasing evidence for the effects of Holocene history on modern biotic communities suggests that current explanations of community patterns and conservation strategies require revisiting. Here we focused on Central European rich fens that are at high risk among mire habitats because of their relatively low environmental stability, and hence sensitivity to successional shifts. At each of 57 study sites, inventory of specialist species of bryophytes, vascular plants and land snails, measurements of local environmental conditions, area, and radiocarbon dating were conducted. We used Moran’s I spatial autocorrelation, multiple linear regression models, MDS, db-RDA, and null models to identify drivers of species richness and occurrence. We tested the importance of site age and historical metacommunity dynamics expressed by regional age of the habitat for the diversity of three taxonomic groups of fen organisms differing in dispersal and life history strategies. The richness of specialist species was affected by local environmental conditions and area in all three groups, but the effect of regional age was significant and positive for vascular plants and snails, once the effect of fen area was set as a covariable. We identified 11 species significantly associated with ancient fens independently of site area and pH effects; this group includes species currently considered to be umbrella species in European habitat conservation (the moss Hamatocaulis vernicosus and the snail Vertigo geyeri). The effect of fen age per se on the communities of specialists calls for the incorporation of age into conservation schemes. Restoration or de novo construction of peat-forming fens cannot compensate for a loss of ancient fens.

Granivorous rodents have been traditionally regarded as antagonistic seed predators. Agoutis (Dasyprocta spp.), however, have also been recognized as mutualistic dispersers of plants because of their role as scatter-hoarders of seeds, especially for large-seeded species. A closer look shows that such definitions are too simplistic for these Neotropical animals because agoutis can influence plant communities not only through seed dispersal of large seeds but also through predation of small seeds and seedlings, evidencing their dual role. Herein, we summarize the literature on plant–agouti interactions, decompose agouti seed dispersal into its quantitative and qualitative components, and discuss how environmental factors and plant traits determine whether these interactions result in mutualisms or antagonisms. We also look at the role of agoutis in a community context, assessing their effectiveness as substitutes for extinct megafaunal frugivores and comparing their ecological functions to those of other extant dispersers of large seeds. We also discuss how our conclusions can be extended to the single other genus in the Dasyproctidae family (Myoprocta). Finally, we examine agoutis’ contribution to carbon stocks and summarize current conservation threats and efforts. We recorded 164 interactions between agoutis and plants, which were widespread across the plant phylogeny, confirming that agoutis are generalist frugivores. Seed mass was a main factor determining seed hoarding probability of plant species and agoutis were found to disperse larger seeds than other large-bodied frugivores. Agoutis positively contributed to carbon storage by preying upon seeds of plants with lower carbon biomass and by dispersing species with higher biomass. This synthesis of plant–agouti interactions shows that ecological services provided by agoutis to plant populations and communities go beyond seed dispersal and predation, and we identify still unanswered questions. We hope to emphasise the importance of agoutis in Neotropical forests.

Chrysomelidae is a family of phytophagous insects with a highly variable degree of trophic specialization. The aim of this study is to test whether species feeding on different plants (generalists) harbour more complex microbiotas than those feeding on a few or a single plant species (specialists). The microbiota of representative leaf beetle species was characterized with a metabarcoding approach targeting V1–V2 and V4 regions of the bacterial 16S rRNA. Almost all the analysed species harbour at least one reproductive manipulator bacteria (e.g., Wolbachia, Rickettsia). Two putative primary symbionts, previously isolated only from a single species (Bromius obscurus), have been detected in two species of the same subfamily, suggesting a widespread symbiosis in Eumolpinae. Surprisingly, the well-known aphid symbiont Buchnera is well represented in the microbiota of Orsodacne humeralis. Moreover, in this study, using Hill numbers to dissect the components of the microbiota diversity (abundant and rare bacteria), it has been demonstrated that generalist insect species harbour a more diversified microbiota than specialists. The higher microbiota diversity associated with a wider host-plant spectrum could be seen as an adaptive trait, conferring new metabolic potential useful to expand the diet breath, or as a result of environmental stochastic acquisition conveyed by diet.

Hong Kong is considered to be a marginal area for coral growth due to its subtropical geography with relatively low winter sea temperatures. Corals can only form non-reefal communities and are believed to host only a low diversity of symbionts with limited flexibility in their symbiont changes. Whether these previously predicted low symbiont diversity is true or is simply a technical artifact and whether these symbionts are generalists or specialists have not fully resolved. To address these issues, we investigated symbiodiniacean diversity and community structure of 30 species of Hong Kong corals using high-throughput sequencing of the nuclear ribosomal RNA gene ITS2. We found high Symbiodiniaceae species richness, with each coral hosting multiple distinct ITS2 symbiont types. Using SymPortal pipeline to alleviate effects of intraspecific ITS polymorphism, the 4662 Symbiodiniaceae ITS2 sequence variants (DIVs) found in our samples were collapsed into 13 distinct ITS2-type profiles, covering Symbiodinium, Breviolum, Cladocopium, and Durusdinium genera, seven of which were coral specific. Cladocopium goreaui was the most diversified (six profiles) and prevalent lineage, dominating the symbiont communities in 29 of the 30 corals species examined. The stress-tolerant Oulastrea crispata was exceptional as its symbionts were dominated by Durusdinium eurythalpos (D13-D13b-D12-D13c profile). Interestingly, Cladocopium C15 was diversified into two ITS2-type profiles, one being Porites lobata specific, while the other was associated with both P. aranetai and P. lutea. Overall, most corals harbor a single dominant generalist symbiont, while some corals host both generalist and specialist symbionts. This work lays the foundation for future research to understand how the generalist and specialist as well as dominant and rare symbionts contribute to the responses and resilience of their host corals against environmental fluctuations in a marginal coral ecosystem, like that in Hong Kong.

Functional diversity metrics have been suggested as important indicators of ecosystem functioning. We investigated the effects of land use mediated by local environmental variables on the fish assemblages’ functional structure in 18 headwater streams distributed in the Upper Parana and Iguacu ecoregions. The species were characterized according to habitat use, food resource use, life history, and hypoxia tolerance. We calculated functional diversity indices [richness (FRic), evenness (FEve), divergence (FDiv), dispersion (FDis), diversity (RaoQ)] and functional rarity indices [distinctiveness (Disti), uniqueness (Uni)], and evaluated the effects of regional and local variables on these indices using generalized linear models. The results highlighted the occurrence of the most functionally distinct and unique species in the forested streams. Moreover, we observed higher FRic in streams sampled in argisol, with a high ammonia load and low habitat diversity. Forested and agricultural covers positively affected FDis and RaoQ. Urban cover had a negative effect on FDis and RaoQ, mainly due to the increase in generalist functional groups in urban streams. Our findings emphasize the importance of forested cover in maintaining specialized species in fish assemblages of streams and preserving functional diversity and ecosystem functioning. Furthermore, these results contribute to direct conservation and recovery measures in freshwater environments.

Geographical distribution and abundance of the pupae of six blackfly species of medical and veterinary concern were studied in eastern Spain according to three different sets of explanatory variables including in-stream variables, both (i) abiotic (i.e., physicochemical) and (ii) biotic (i.e., richness and abundance of either taxonomically or ecologically close related taxa), as well as (iii) meteorological and landscape variables. The results showed specific habitat requirements for pupation in Simulium (Boophthora) erythrocephalum (De Geer, 1776) and Simulium (Wilhelmia) equinum (Linnaeus, 1758), two of the six species studied regarding elevation and temperature. While the rest of the species showed a certain degree of ecological overlap, co-occurrence was in general low, which suggested that antagonistic biotic factors may be important in structuring blackfly assemblages. In effect, biotic predictors explained a high proportion (50%-70%) of the variability in the abundance of the pupae of the most generalist blackfly species, although further studies are needed to disentangle the sign of interspecific interactions. At the landscape level, S. (W.) equinum and S. (W.) pseudequinum Séguy, 1921 breeding habitats were associated with the presence of pig farms, and S. (Simulium) reptans (Linnaeus, 1758) and S. (B.) erythrocephalum with the presence of cattle.

Plant growth promoting microorganisms (PGPMs) are inhabitants of the rhizosphere that are able to provide better growth and biomass accumulation. Current agronomic practices have depleted these communities, which has created the opportunity for the development of commercial inoculants. These products use strains that are able to interact with a wide range of plant species and survive in diverse environments. The use of these generalist strains is required for providing a widespread solution that aggregates enough demand to reach market scale. Growth promotion by generalist strains may be suboptimal in comparison to the effect provoked by native and host-specific populations, but these specialist strains are not a market-available solution. In this work, we assess the nitrogen, phosphorus and potassium (NPK) use efficiency provided by commercial inoculants to cassava plants using Data Envelopment Analysis (DEA) to demonstrate the advantages of conceiving nutrient-limited yield as a production function. We also estimate the prospective production frontier that commercial inoculants can provide to cassava plants. Our results suggest that commercial inoculants have potential for improving cassava yields via improved NPK use efficiency. The methods presented here offer an ecological/economic production framework for the assessment of PGPMs and PGPMs-based commercial inoculants that can be extended to other laboratory, greenhouse or field situations. The simple, intuitive and graphical approximation that DEA offers will facilitate the understanding of the concept of technical efficiency and the role of commercial inoculants on closing yield gaps.

Habitat loss is currently a major threat to biodiversity, affecting species interactions, such as plant-pollinator interactions. This is particularly important in self-incompatible plants relying on pollinators to reproduce and sustain their populations. Here, we evaluated how habitat loss affects the pollination system, plant individual-pollinator species interaction network, and plant reproductive fitness of the self-incompatible Jasione maritima var. sabularia, a threatened taxon from dune systems. This plant is a pollinator generalist, visited by 108 species from distinct taxonomic groups. Results suggest that increasing habitat loss led to a significant decline in pollinator richness, increased pollen limitation, and a decrease in reproductive fitness of J. maritima var. sabularia. Visitation rate per individual did not significantly change with available area, indicating that the quality of pollen differed across populations. The topology of the network between J. maritima var. sabularia individuals and its pollinator species did not change, which may be attributed to the stability in the core of pollinator species. This suggests that the lower fitness of plants with increasing habitat degradation may be explained not only by the lower richness of peripheral pollinators but also by the genetic structure of the plant populations, as there is a possible higher transference of less quality pollen by pollinators, ultimately compromising the persistence of plant populations. Our study highlights the need of future studies to integrate the fine details provided by individual-level networks, which will increase our understanding of the pattern of species interactions and its consequences for the fitness of threatened plant populations.

This research investigated the self-efficacy, beliefs, and practices of generalist primary school teachers who undertook the Bachelor of Education with a specialism in PE between 2016 and 2019. Dat...

The degradation of natural ecosystems due to land use changes has been increasing, altering ecosystem composition, structure and processes, which negatively affects biodiversity. Herein, we explored how the diversity patterns of anurans respond to the scenario of extensive replacement of grasslands with agriculture in southernmost Brazil. We determined possible changes in the species richness, taxonomic composition, and structure of pond-breeding anuran communities in the grassland ecosystems of the South Brazilian Grasslands (SBG). Using the survey at breeding sites method, we sampled a total of 238 ponds, 153 from extensive livestock grazing on grasslands and 85 from agricultural areas. The higher species richness was found in the livestock areas on grasslands. There was a significant nestedness pattern associated with agricultural areas, indicating a non-random process of community simplification by species loss. Seven anuran species were considered land use indicators, of which five were considered indicators of grasslands with livestock, and two as indicators of agricultural areas. Generalist species were persistent and dominant in agricultural areas, while habitat specialists disappeared from these areas. Land use was a significant factor explaining the community structure segregation between land uses regardless of the natural variation reported at the local and regional levels. We highlight the importance of grasslands for the conservation of pond-breeding anurans in non-forest landscapes of the subtropical region, and we discuss the view that extensive livestock production needs strategic incentives to help the conservation of SBG biodiversity, such as multi-institutional measures.

Background In Antarctica, summer sunlight enables phototrophic microorganisms to drive primary production, thereby “feeding” ecosystems to enable their persistence through the long, dark winter months. In Ace Lake, a stratified marine-derived system in the Vestfold Hills of East Antarctica, a Chlorobium species of green sulphur bacteria (GSB) is the dominant phototroph, although its seasonal abundance changes more than 100-fold. Here, we analysed 413 Gb of Antarctic metagenome data including 59 Chlorobium metagenome-assembled genomes (MAGs) from Ace Lake and nearby stratified marine basins to determine how genome variation and population structure across a 7-year period impacted ecosystem function. Results A single species, Candidatus Chlorobium antarcticum (most similar to Chlorobium phaeovibrioides DSM265) prevails in all three aquatic systems and harbours very little genomic variation (≥ 99% average nucleotide identity). A notable feature of variation that did exist related to the genomic capacity to biosynthesize cobalamin. The abundance of phylotypes with this capacity changed seasonally ~ 2-fold, consistent with the population balancing the value of a bolstered photosynthetic capacity in summer against an energetic cost in winter. The very high GSB concentration (> 108 cells ml−1 in Ace Lake) and seasonal cycle of cell lysis likely make Ca. Chlorobium antarcticum a major provider of cobalamin to the food web. Analysis of Ca. Chlorobium antarcticum viruses revealed the species to be infected by generalist (rather than specialist) viruses with a broad host range (e.g., infecting Gammaproteobacteria) that were present in diverse Antarctic lakes. The marked seasonal decrease in Ca. Chlorobium antarcticum abundance may restrict specialist viruses from establishing effective lifecycles, whereas generalist viruses may augment their proliferation using other hosts. Conclusion The factors shaping Antarctic microbial communities are gradually being defined. In addition to the cold, the annual variation in sunlight hours dictates which phototrophic species can grow and the extent to which they contribute to ecosystem processes. The Chlorobium population studied was inferred to provide cobalamin, in addition to carbon, nitrogen, hydrogen, and sulphur cycling, as critical ecosystem services. The specific Antarctic environmental factors and major ecosystem benefits afforded by this GSB likely explain why such a coherent population structure has developed in this Chlorobium species.

Species confined to naturally fragmented habitats may exhibit intrinsic population complexity which may challenge interpretations of species response to anthropogenic landscape transformation. In South Africa, where native forests are naturally fragmented, forest‐dependent birds have undergone range declines since 1992, most notably among insectivores. These insectivores appear sensitive to the quality of natural matrix habitats, and it is unknown whether transformation of the landscape matrix has disrupted gene flow in these species. We undertook a landscape genetics study of four forest‐dependent insectivorous songbirds across southeast South Africa. Microsatellite data were used to conduct a priori optimization of landscape resistance surfaces (land cover, rivers and dams, and elevation) using cost‐distances along least‐cost pathway (LCP), and resistance distances (IBR). We detected pronounced declines in effective population sizes over the past two centuries for the endemic forest specialist Cossypha dichroa and Batis capensis, alongside recent gene flow disruption in B. capensis, C. dichroa and Pogonocichla stellata. Landscape resistance modelling showed both native forest and dense thicket configuration facilitates gene flow in P. stellata, B. capensis and C. dichroa. Facultative dispersal of P. stellata through dense thicket likely aided resilience against historic landscape transformation, whereas combined forest‐thicket degradation adversely affected the forest generalist B. capensis. By contrast, Phylloscopus ruficapilla appears least reliant upon landscape features to maintain gene flow and was least impacted by anthropogenic landscape transformation. Collectively, gene flow in all four species is improved at lower elevations, along river valleys, and riparian corridors— where native forest and dense thicket better persist. Consistent outperformance of LCP over IBR land‐cover models for P. stellata, B. capensis and C. dichroa demonstrates the benefits of wildlife corridors for South African forest‐dependent bird conservation, to ameliorate the extinction debts from past and present anthropogenic forest exploitation.

Adaptations to anthropogenic domestic habitats contribute to the success of the mosquito Aedes aegypti as a major global vector of several arboviral diseases. The species inhabited African forests before expanding into domestic habitats and spreading to other continents. Despite a well‐studied evolutionary history, how this species initially moved into human settlements in Africa remains unclear. During this initial habitat transition, African Ae. aegypti switched their larval sites from natural water containers like tree holes to artificial containers like clay pots. Little is known about how these natural versus artificial containers differ in their characteristics. Filling this knowledge gap could provide valuable information for studying the evolution of Ae. aegypti associated with larval habitat changes. As an initial effort, in this study, we characterized the microenvironments of Ae. aegypti larval sites in forest and domestic habitats in two African localities: La Lopé, Gabon, and Rabai, Kenya. Specifically, we measured the physical characteristics, microbial density, bacterial composition, and volatile chemical profiles of multiple larval sites. In both localities, comparisons between natural containers in the forests and artificial containers in the villages revealed significantly different microenvironments. We next examined whether the between‐habitat differences in larval site microenvironments lead to differences in oviposition, a key behavior affecting larval distribution. Forest Ae. aegypti readily accepted the artificial containers we placed in the forests. Laboratory choice experiments also did not find distinct oviposition preferences between forest and village Ae. aegypti colonies. These results suggested that African Ae. aegypti are likely generalists in their larval site choices. This flexibility to accept various containers with a wide range of physical, microbial, and chemical conditions might allow Ae. aegypti to use human‐stored water as fallback larval sites during dry seasons, which is hypothesized to have initiated the domestic evolution of Ae. aegypti., This study characterized Aedes aegypti larval sites in forest versus domestic habitats in La Lope, Gabon, and Rabai, Kenya. The results suggested that larval sites in different habitats have very different microenvironments. However, behavioral experiments did not find strong evidence of ovipositional difference, suggesting that African Ae. aegypti could be a generalist in oviposition and larval site choices.

The host range of parasitoids varies greatly among species: Some only parasitize one to a few hosts (specialists), while others parasitize multiple species or a va-riety of host types (generalists). The direction of most host range shifts in parasi-toid groups, that is from generalist to specialist or, alternatively, from specialist to generalist, is unknown. To explore the origin of host range shifts, we studied a clade within the genus Torymus(Hymenoptera, Chalcidoidea) that includes both generalist and specialist parasitoids of Cynipidae (Hymenoptera). We ana-lysed the phylogenetic relationships of the species of Torymuson the basis of two gene fragments (cox1and ITS2) of 246 specimens and performed an ancestral state reconstruction of the specialist/generalist trait. Our results revealed the fol-lowing: (a) The ancestral state of this group of Torymusis specialist, with the generalist state evolving through a loss of specialization. (b) The species Torymus cyaneusand Torymus flavipesboth have a strong genetic structure, suggesting the existence of different biological identities. (c) There has been a host plant shift in the lineage(s) leading to Torymus rubiand Torymus bedeguarisfrom galls on Quercusto those on Rosaceae. (d) The alien species Torymus sinensisand the native European species Torymus notatusare phylogenetically closely related. (e) Speciation within Torymuswas likely associated with the diversification of their cynipid hosts, which itself was driven by the dramatic changes in climate and vegetation that occurred during the Miocene., The molecular work was funded by the project grants CGL2015-66571-P MINECO- FEDER and PID2019- 110243GB- 100/AEI/10.13039/501100011033 (Ministerio de Ciencia, Innovación y Universidades, Spain) to MG- P; and the field samplings by AGL2016-76262-R (AEI/FEDER, UE) and Encomienda de Gestión from MAPAMA to Agencia Estatal CSIC, 16MNES003 to JLNA.

Morphological trait-matching and species abundance are thought to be the main factors affecting the frequency and strength of mutualistic interactions. However, the relative importance of trait-matching and species abundance in shaping species interactions across environmental gradients remains poorly understood, especially for plant-insect mutualisms involving generalist species. Here, we characterised variation in species and trait composition and the relative importance of trait-matching and species abundance in shaping plant-Hymenoptera and plant-Diptera mutualisms in four meadows across an elevational gradient (2,725-3,910 m) in Yulong Snow Mountain, Southwest China. We also evaluated the effects of morphological traits of flower visitors and plant composition on their foraging specialisation (d' and normalised degree). There was a high degree of dissimilarity in the composition of Hymenoptera and Diptera visitors and their visited plants between communities. This variation was mainly driven by the spatial replacement of species. Both for plant-Hymenoptera and plant-Diptera networks, trait-matching between nectar tube depth and proboscis length was a stronger predictor of the interactions between temporally co-occurring plants and flower visitors than species abundance. Fourth-corner analyses revealed statistically significant trait-matching between nectar tube depth and proboscis length in plant-Hymenoptera networks at all sites, suggesting that Hymenoptera consistently foraged on plant species with nectar tube depths matching their proboscis lengths. By contrast, significant trait-matching in plant-Diptera networks was only observed at the two lower elevation sites. The species-level specialisation d' of flower visitors increased significantly as the proboscis length and the difference in nectar tube depth between the plant community and the plants visited by flower visitors increased. Our results highlight that the importance of trait-matching in shaping pairwise interactions and niche partitioning depends on the specific features (e.g. species composition and trait availability) of the plant-pollinator system. For specialised plant-Hymenoptera systems, trait-matching is an important determinant of species interactions, whereas for generalist plant-Diptera systems, trait-matching is relatively unimportant., H.W. was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31000000), the Joint Fund of the National Natural Science Foundation of China-Yunnan Province (U1502261), the Yunling Scholarship of Yunnan Provincial Government (YLXL20170001) and National Natural Science Foundation of China (32071670). Y.-H.Z. was supported by the National Natural Science Foundation of China (31700361) and the Chinese Academy of Sciences ‘Light of West China’ Program. A.L. was supported by a Ramóny Cajal (RYC-2015-19034) contract from the Spanish Ministry of Science, Innovation and Universities, the Spanish State Research Agency, European Social Funds (ESF invests in your future), and the University of the Balearic Islands, and by the project CGL2017-89254-R financed by the Spanish Ministry of Economy and Competitiveness, Feder Funds, and the Spanish Research Agency (Call 2017).

The study of invasive species often focuses on regions of recent introduction rather than native habitats. Understanding an invasive species in its natural environment, however, can provide important insights regarding the long-term outcome of invasions. In this study we investigated the diet of the invasive spiny water flea, Bythotrephes longimanus, in two Austrian perialpine lakes, where it is native. The gut contents of wild-caught Bythotrephes individuals were estimated by quantitative polymerase chain reaction, targeting species-specific fragments of the barcoding region of the cytochrome c oxidase I gene of potential prey. The observed prey spectrum of Bythotrephes in the study lakes consisted primarily of Eudiaptomus gracilis and Diaphanosoma brachyurum. The Daphnia longispina complex, Leptodora kindtii and Mesocyclops leuckarti also contributed to the diet. Results indicate that Bythotrephes is a generalist feeder with a preference for epilimnetic prey.

Surveys of patterns of genetic variation in natural sympatric and allopatric populations of recently diverged species are necessary to understand the processes driving intra- and interspecific diversification. The South American moths Cactoblastis cactorum, Cactoblastis doddi and Cactoblastis bucyrus are specialized in the use of cacti as host plants. These species have partially different geographic ranges and differ in patterns of host plant use. However, there are areas that overlap, particularly, in northwestern Argentina, where they are sympatric. Using a combination of genome-wide SNPs and mitochondrial data we assessed intra and interspecific genetic variation and investigated the relative roles of geography and host plants on genetic divergence. We also searched for genetic footprints of hybridization between species. We identified three well delimited species and detected signs of hybridization in the area of sympatry. Our results supported a hypothetical scenario of allopatric speciation in the generalist C. cactorum and genetic interchange during secondary geographic contact with the pair of specialists C. bucyrus and C. doddi that probably speciated sympatrically. In both cases, adaptation to new host plants probably played an important role in speciation. The results also suggested the interplay of geography and host plant use as drivers of divergence and limiting gene flow at intra and interspecific levels.

The role of generalist predators has long been considered an important component of mortality for many agricultural pests but can be difficult to quantify. We present the use of digital imaging as ...

Understanding resource preference and use pattern in avian community will add a significant value in conservation and management of birds as well as forest restoration and landscape management in the region. We studied the foraging behaviour of 26 bird species at three resource dimensions—foraging height, foraging substrate and foraging method—in a sub-tropical forest in East district of Sikkim, Eastern Himalaya, India during August 2018 to April 2019. Most bird species utilized 0–5 m height category, whereas on the basis of foraging substrate, twigs were used by majority of the species for foraging. Similarly, wood gleaning method was used by maximum species of birds for feeding. Niche width was highest in Blue Whistling Thrush Myophonus caeruleus and lowest in Spotted Dove Stigmatopella chinensis. On the other hand, niche overlap was found to be highest between pair of Green-crowned Warbler Seicerus burkii and Grey-hooded Warbler Phylloscopus xanthoschistos, whereas some of the pairs showed complete niche segregation. Bird species showing higher overlap in one dimension were found to be showing no or lesser overlap in another dimension. Specialization was found to be higher in foraging substrate followed by foraging method and foraging height. In all three dimensions, important specialist species were identified during the study that called for conservation efforts.

This article contributes to the discussion of the implications of different objectives pursued by the competition authorities (CAs) for their optimal structure in terms of whether one or more functions (or activities) should be assigned to them. Different areas of enforcement activity that can be assigned to CAs may differ in the extent to which they contribute to welfare-enhancing or reputation-enhancing objectives. In their recent paper, Avdasheva et al. (Rev Ind Organ 54:251–282, 2019) showed that when the CAs are reputation-maximizing, it may then be optimal to have activities undertaken by specialist authorities, each specializing in one activity. In this article, we generalize the utility function of the CAs, allowing also the welfare impact of the decisions made to influence their utility, and show that if the CAs are welfare maximizers, then all the activities should be undertaken by one generalist authority.

Previous work, using morphological characters, identified a generalist copepod parasite (Pharodes tortugensis) at high prevalence on two common gobies (Coryphopterus glaucofraenum and C. dicrus) in the British Virgin Islands (BVI). DNA barcoding subsequently revealed C. glaucofraenum to be three morphologically similar species (C. glaucofraenum, C. venezuelae and C. tortugae), casting doubt on host identities in the BVI and the classification of the parasite as a single species. Mitochondrial cytochrome c oxidase subunit I (COI) data from 67 gobies in the BVI showed that, in addition to C. dicrus, host gobies were a mix of C. glaucofraenum and C. venezuelae, while C. tortugae was unexpectedly absent from the study area. COI data (n = 70) indicated that the copepod infecting all three hosts was a single species, almost certainly P. tortugensis. The pharodes-coryphopterus interaction has a strong impact on host dynamics in the BVI, and a revised understanding of these dynamics must account for any differences among the three newly confirmed hosts in transmission of, and susceptibility to, the shared parasite. No other infected hosts were discovered at our sites, but P. tortugensis is reportedly widespread and infects 12 additional host species elsewhere. Further DNA barcoding is thus needed to test whether P. tortugensis is truly a widespread generalist, or instead represents a group of more specialized cryptic species.

Decisions made by foraging animals conform a complex process based on the integration of information from multiple external environmental stimuli and internal physiological signals, which in turn are modulated by individual experience and a detection threshold of each individual. For social insects in which foraging is limited to given age subcastes, individual foraging decisions may also be affected by ontogenetic shifts and colony requirements. We studied the short-term changes in foraging preferences of the generalist wasp Vespula germanica, focusing on whether the individual response to different resources could be influenced by the ontogenetic shifts and/or by social interaction with nestmates. We carried both laboratory and field experiments to confront worker wasps to a short-term resource switch between either protein or carbohydrate-based foods. We tested the response of (1) Preforager workers (no foraging experience nor interaction with other wasps), (2) Forager workers (experience in foraging and no colony feedback), and (3) Wild forager workers (foraging naturally and exposed to free interactions with nestmates). We evaluated the maxilla-labium extension response (MaLER) for laboratory assays or the landing response for field assays. We observed that for wasps deprived of colony feedback (either preforagers or foragers), the protein-rich foods acceptance threshold increased (and thus a lower level of foraging on that item was observed) if they had foraged on carbohydrates previously, whereas carbohydrates were accepted in all assays. However, wasps immersed in a natural foraging context did accept protein foods regardless of their first foraging experience and reduced the carbohydrates collected when trained on protein foods. We provide evidence that short-term changes in foraging preferences depend on the type of resource foraged and on the social interactions, but not on ontogenetic shifts.

The specialist versus generalist strategies of hemoparasites in relation to their avian host, as well as environmental factors, can influence their prevalence, diversity and distribution. In this paper we investigated the influence of avian host species, as well as the environmental and geographical factors, on the strategies of Haemoproteus and Plasmodium hemoparasites. We determined prevalence and diversity by targeting their cytochrome b (Cytb) in a total of 2,590 passerine samples from 138 localities of Central and South America, and analysed biogeographic patterns and host-parasite relationships. We found a total prevalence of 23.2%. Haemoproteus presented a higher prevalence (15.3%) than Plasmodium (4.3%), as well as a higher diversity and host specificity. We determined that Plasmodium and Haemoproteus prevalences correlated positively with host diversity (Shannon index) and were significantly influenced by bird diversity, demonstrating a possible "amplification effect". We found an effect of locality and the avian family for prevalences of Haemoproteus and Plasmodium. These results suggest that Haemoproteus is more specialist than Plasmodium and could be mostly influenced by its avian host and the Andes Mountains.

The patterns of diet specialization in food webs determine community structure, stability, and function. While specialists are often thought to evolve due to greater efficiency, generalists should have an advantage in systems with high levels of variability. Here we test the generalist-disturbance hypothesis using a dynamic, evolutionary food web model. Species occur along a body size axis with three traits (body size, feeding center, feeding range) that evolve independently and determine interaction strengths. Communities are assembled via ecological and evolutionary processes, where species biomass and persistence are driven by a bioenergetics model. New species are introduced either as mutants similar to parent species in the community or as invaders, with dissimilar traits. We introduced variation into communities by increasing the dissimilarity of invading species across simulations. We found that strange invaders increased the variability of communities which increased both the degree of generalism and the relative persistence of generalist species, indicating that invasion disturbance promotes the evolution of generalist species in food webs.

Throughout their life cycle, parasitic organisms experience a variety of environmental conditions. To ensure persistence and transmission, some protozoan parasites are capable of adjusting their replication or converting to distinct life cycle stages. Trypanosoma cruzi is a 'generalist' parasite that is competent to infect various insect (triatomine) vectors and mammalian hosts. Within the mammalian host, T. cruzi replicates intracellularly as amastigotes and can persist for the lifetime of the host. The persistence of the parasites in tissues can lead to the development of Chagas disease. Recent work has identified growth plasticity and metabolic flexibility as aspects of amastigote biology that are important determinants of persistence in varied growth conditions and under drug pressure. A better understanding of the link between amastigote and host/tissue metabolism will aid in the development of new drugs or therapies that can limit disease pathology.

Wireworms, the soil-dwelling larvae of click beetles, are a major threat to global agricultural production. This is largely due to their generalist polyphagous feeding capabilities, extended and cryptic life cycles, and limited management options available. Although wireworms are well-documented as economically important pests in the Canadian Prairies, including Manitoba, there are gaps in knowledge on species distributions, subterranean behaviour and life cycles, feeding ecology and damage capacity, and economic thresholds for crop yield loss.We carried out 3 years (2018-2020) of intensive surveillance of larval populations across Manitoba. A total of 31 fields (24 in ≥ 2 consecutive years) were surveyed in early spring using standardized bait trapping approaches. Wireworms were present in 94% of surveyed sites, but the catch within fields varied year to year. While Hypnoidus bicolor predominated (94% of larvae), several other pest species were identified. We then explored the relationships between wireworm trap numbers and agro-environmental factors. The larval catch tended to decrease under conditions of low soil temperatures and increased clay content, coupled with high soil moisture and precipitation during the trapping period. Treatment and cultural methods appeared less influential; however, wheat production in either of the previous two growing seasons was associated with increased wireworm catch. Our models failed to predict a relationship between wireworm catch and crop yields, although infestations were rare in our region.Our findings better infer the risks posed by wireworms to crop production in the Canadian Prairies, and the agro-environmental factors that represent the greatest contributors to these risks. This information should be incorporated into future integrated pest management (IPM) strategies for wireworms. © 2021 Her Majesty the Queen in Right of Canada Pest Management Science © 2021 Society of Chemical Industry Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.

Trait adaptation to a heterogeneous environment can occur through six modes: genetic differentiation of those traits, a jack-of-all-trades phenotypic uniformity, diversified bet-hedging, phenotypic plasticity, habitat choice, and habitat construction. A key question is what circumstances favor one mode over another, and how they might interact if a system can express more than one mode at a time. We examined the joint evolution of habitat choice and habitat construction using individual-based simulations. We manipulated when during the life cycle construction occurred and the fitness value of construction. We found that for our model habitat construction was nearly always favored over habitat choice, especially if construction happened after dispersal. Because of the ways that the various modes of adaptation interact with each other, there is no simple answer as to which will be favored; it depends on details of the biology and ecology of a given system.

One of the important parts of the job of a journal editor is finding good peer reviewers.1 In this editorial I investigate the peer review process in the context of the Journal of the American Plan...

The scleractinian reef building coral Madracis decactis is a cosmopolitan species. Understanding host–symbiont associations is critical for assessing coral’s habitat requirements and its response to environmental changes. In this study, we performed a fine grained phylogenetic analyses of Symbiodiniaceae associated with Madracis in two locations in the Southwest Atlantic Ocean (Abrolhos Bank and St. Peter and St. Paul Archipelago). Previous studies have argued that Madracis is a specialist coral, with colonies harboring a single symbiont from the genus Breviolum (formerly clade B). However, these previous studies have not precisely addressed if Madracis is colonized by several types of Symbiodiniaceae simultaneously or whether this coral is a specialist. The hypothesis that Madracis is a generalist coral host was evaluated in the present study. A total of 1.9 million reads of ITS2 nuclear ribosomal DNA were obtained by Illumina MiSeq sequencing. While Symbiodiniaceae ITS2 sequences between two sampling depths were almost entirely (62%) from the genus Breviolum (formerly clade B), shallow (10–15 m) populations in Abrolhos had a greater diversity of ITS2 sequences in comparison to deeper (25–35 m) populations of St. Peter and St. Paul Archipelago. Cladocopium (formerly clade C) and Symbiodinium (formerly clade A) were also found in Abrolhos. A single Madracis colony can host different symbiont types with > 30 Symbiodiniaceae ITS2-type profiles. Abrolhos corals presented a higher photosynthetic potential as a possible result of co-occurrence of multiple Symbiodiniaceae in a single coral colony. Multiple genera/clades of Symbiodiniaceae possibly confer coral hosts with broader environmental tolerance and ability to occupy diverse or changing habitats.

Habitat loss threatens insect diversity globally. However, complementary vegetation types in remaining habitat increases opportunities for species survival. We assess the extent to which indigenous forest patches moderate the impact of exotic commercial afforestation on grassland butterflies. Butterflies were sampled in grassland along uncorrelated gradients of landscape-scale indigenous forest and plantation cover, while controlling for variation in local vegetation composition. We separately assessed responses by butterfly groups differing in habitat preference, larval diet, and mobility. There was no effect of landscape- or local-scale variables on species richness, but there was a strong interactive effect of forest and plantation cover on butterfly assemblage structure. The effect varied according to species traits. When forest cover was high, assemblages did not differ at different levels of plantation cover. However, plantation cover significantly influenced assemblage structure when forest cover was low. Grassland with limited forest cover in the protected area supported unique assemblages with high frequency of less mobile, specialized species with herbaceous larval host plants, whereas grassland with low forest cover near plantations had a prevalence of mobile, generalist species. A positive association between forest cover and butterflies with woody larval host plants suggests that indigenous forest patches improved the suitability of fragmented grassland for a subset of butterflies, emphasising the value of natural heterogeneity in transformed areas. However, certain butterfly traits associated with large, open grassland were under-represented in grassland between plantations, underscoring the importance of open areas in the broader landscape to conserve the full diversity of species.

Bees foraging in agricultural habitats can be exposed to plant protection products. To limit the risk of adverse events, a robust risk assessment is needed, which requires reliable estimates for the expected exposure. The exposure pathways to developing solitary bees in particular are not well described and, in the currently proposed form, rely on limited information. To build a scaling model predicting the amount of protein developing solitary bees need based on adult body weight, we used published data on the volume of pollen solitary bees provide for their offspring. This model was tested against and ultimately updated with additional literature data on bee weight and protein content of emerged bees. We rescaled this model, based on the known pollen protein content of bee-visited flowers, to predict the expected amount of pollen a generalist solitary bee would likely provide based on its adult body weight, and tested these predictions in the field. We found overall agreement between the models' predictions and the measured values in the field, but additional data are needed to confirm these initial results. Our study suggests that scaling models in the bee risk assessment could complement existing risk assessment approaches and facilitate the further development of accurate risk characterization for solitary bees; ultimately the models will help to protect them during their foraging activity in agricultural settings. Integr Environ Assess Manag 2022;18:308-313. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental ToxicologyChemistry (SETAC).

Gough Moorhens Gallinula comeri were introduced to Tristan da Cunha in the 1950s, and are now numerous in lowland habitat, filling the ecological niche of the extinct Tristan Moorhen G. nesiotis. On their native Gough Island, moorhens have a varied diet, ranging from vegetation and fruits to scavenging and even predatory behaviour. Here, we examined the stomach contents of four birds on Tristan da Cunha to provide insight into their diet. Moorhens mostly ate vegetation, but we also recorded spiders (Arthropoda: Aranea), earthworms (Oligochaeta: Lumbricidae), remains of introduced rodents (Mus musculus), and anthropogenic debris. As on Gough Island, moorhens on Tristan have a generalist diet, and the impact of ecosystem restoration (and of the moorhens themselves) should be considered.

Aims Gypsum soils are P-limited atypical soils that harbour a rich endemic flora. These singular soils are usually found in drylands, where plant activity and soil nutrient availability are seasonal. No previous studies have analysed the seasonality of P nutrition and its interaction with the arbuscular mycorrhiza fungi (AMF) colonisation in gypsum plants. Our aim was to evaluate the seasonal changes in plant nutrient status, AMF colonisation and rhizospheric soil nutrient availability in gypsum specialist and generalist species. Methods We evaluated seasonal variation in the proportion of root length colonised by AMF structures (hyphae, vesicules and arbuscules), plant nutrient status (leaf C, N and P and fine root C and N) and rhizospheric soil content (P, organic matter, nitrate and ammonium) of three gypsum specialists and two generalists throughout a year. Results All species showed arbuscules within roots, including species of Caryophyllaceae and Brassicaceae. Root colonisation by arbuscules (AC) was higher in spring than in other seasons, when plants showed high leaf P-requirements. Higher AC was decoupled from inorganic N and P availability in rhizospheric soil, and foliar nutrient content. Generalists showed higher AC than specialists, but only in spring. Conclusions Seasonality was found in AMF colonisation, rhizospheric soil content and plant nutrient status. The mutualism between plants and AMF was highest in spring, when P-requirements are higher for plants, especially in generalists. However, AMF decoupled from plant demands in autumn, when nutrient availability increases in rhizospheric soil.

Rough scad Trachurus lathami is a key pelagic fish in the Argentinean continental shelf (ACS, south-west Atlantic Ocean), with recent increases in abundance. It is a main prey of fishes and marine mammals, and shares the environment with commercially relevant pelagic species (Engraulis anchoita and Scomber colias), playing an important role linking lower and upper trophic levels in the ecosystem. This study aims to determine the ontogenetic changes in the diet composition, feeding strategy, trophic niche breadth and trophic level of T. lathami in the North Patagonian Shelf (43°-45°30'S). The stomach contents of adult fish (n = 238) were analysed. The results suggest a clear ontogenetic shift in the diet at a size of ~190 mm. Smaller individuals (160-190 mm) were specialized on misidaceans, and showed the highest trophic level, while larger T. lathami (221-230 mm) consumed decapods (Peisos petrunkevitchi) and teleosts (eggs and larvae). Trophic niche breadth was higher at the medium-sized class (191-220 mm), which mainly preyed on copepods (Calanoides carinatus) and chaetognaths (Sagitta spp.), evidencing a more diverse diet and a rather generalist strategy. Updated information on the trophic ecology of T. lathami evidences its extremely plastic feeding behaviour, being able to adapt its trophic niche to the most readily available food items from the mesopelagic community.

Although cerrado trees have evolved with fire for millions of years, it is not well-understood which tree attributes are more important to survive fire in the Brazilian savanna. To address this issue, we used pre- and post-fire data on 367 cerrado trees (113 native species) planted in an arboretum in south-east Brazil and then left unburnt until 2019, when a prescribed burn was applied. Tree size (height and diameter) had been measured in 2017. Four months after the fire, we assessed tree size, relative bark thickness (bark-to-diameter ratio), leaf habit (evergreen or deciduous) and habitat preference (savanna specialist or generalist). These were the predictor variables used in generalised linear models exploring tree survival and resprouting type. Most trees survived fire: 59% resprouted epicormically, 25% resprouted basally, 6% had root suckers, and only four trees died. Basal and epicormic resprouting were related to tree size: small trees (diameter ≤ 5 cm) resprouted basally more frequently, whereas tall trees (height ≥ 3.7 m) resprouted epicormically more frequently. Our results suggest that rapid growth is more important than bark thickness, leaf habit or habitat preference to escape the fire trap, because it allows cerrado trees to reach a fire-resistant height more quickly.

This exploratory research suggests that undergraduate marketing research textbooks and courses have not kept pace with the changes in the marketing research world over the past two decades. Two studies, one a review of marketing research syllabi and another a content analysis of online job postings, explore this phenomenon. The results imply that, in contrast to the historical context of marketing research course, most advertised entry-level marketing jobs requiring marketing research skills are not in marketing research firms. Indeed, contemporary marketing research is more likely a function embedded within an array of generalist job duties that also require soft skills and the ability to analyze and present data to upper management. As a result of this research, educators should have a heightened awareness of the following: (a) the disconnect between the marketing research curriculum and current industry needs, (b) the changing role of marketing research as diffused throughout the organization, and (c) the broader set of skills and techniques required of entry-level marketing graduates. As a possible solution to these issues, this research proposes an integrated model whereby instructors can help their students navigate the current landscape by choosing an appropriate pedagogical path to assist students in their career goals.

Glossogobius sparsipapillus is a potential candidate for aquaculture in the Mekong Delta, but information on its food and feeding habit is still fragmented and deficient. This study, therefore, aims to contribute diet and feeding ecology to this fish based on 661 specimens (331 males and 330 females) caught in estuarine areas from December 2019 to November 2020. Data analysis showed that fish diet composition comprised five categories such as Acetes spp., small fish, Polychaeta, Uca spp., and others (e.g., fish scales and detritus). This goby is a generalist feeder, feeding preliminarily on Acetes spp. but rarely on Polychaeta. Feeding intensity is high and does not change with sexes but varies according to fish sizes, seasons, and sites. Moreover, a similar meal size was observed in different sexes, fish sizes, seasons, and sites. The findings supply the fundamental knowledge on the food and feeding of this species, being used for artificially cultivating study.

Tritrophic relationships involving tarsonemids and predatory phytoseiids are common in a variety of agroecosystems, but due to the wide range of diets in both families, it is necessary to understand what food resources they are consuming to determine potential impact on crops. We investigated a frequent association of cucurbit powdery mildew (Podosphaera xanthii), Tarsonemus bilobatus, and Proprioseiopsis mexicanus in watermelon and pumpkin fields to determine whether P. mexicanus is consuming either or both of the other organisms. We also examined developmental and reproductive capability of P. mexicanus on these diets. If P. mexicanus is an effective predator of T. bilobatus, it may also be useful in controlling pest tarsonemids, such as broad mites. Proprioseiopsis mexicanus either starved or escaped from arenas rather than consume P. xanthii. When consuming T. bilobatus, P. mexicanus females developed from larva to adult in ca. 3 days. On this diet, the preoviposition period was ca. 2 days and P. mexicanus laid 1.7 eggs/day. These results are comparable to some of the higher-quality non-prey resources investigated in the literature. Starved female P. mexicanus consumed 6.5 T. bilobatus of mixed stages in 1 h. This study provides support for further research into the importance of non-pest tarsonemids as a resource to maintain the presence of generalist predatory mites as an early-intervention natural enemy. Further work should examine the efficacy of P. mexicanus as a natural enemy of economically important pest tarsonemids.

Molt is critical for birds as it replaces damaged feathers and worn plumage, enhancing flight performance, thermoregulation, and communication. In passerines, molt generally occurs on the breeding grounds during the postbreeding period once a year. However, some species of migrant passerines that breed in the Nearctic and Western Palearctic regions have evolved different molting strategies that involve molting on the overwintering grounds. Some species forego molt on the breeding grounds and instead complete their prebasic molt on the overwintering grounds. Other species molt some or all feathers a second time (prealternate molt) during the overwintering period. Using phylogenetic analyses, we explored the potential drivers of the evolution of winter molts in Nearctic and Western Palearctic breeding passerines. Our results indicate an association between longer photoperiods and the presence of prebasic and prealternate molts on the overwintering grounds for both Nearctic and Western Palearctic species. We also found a relationship between prealternate molt and generalist and water habitats for Western Palearctic species. Finally, the complete prealternate molt in Western Palearctic passerines was linked to longer days on the overwintering grounds and longer migration distance. Longer days may favor the evolution of winter prebasic molt by increasing the time window when birds can absorb essential nutrients for molt. Alternatively, for birds undertaking a prealternate molt at the end of the overwintering period, longer days may increase exposure to feather‐degrading ultra‐violet radiation, necessitating the replacement of feathers. Our study underlines the importance of the overwintering grounds in the critical process of molt for many passerines that breed in the Nearctic and Western Palearctic regions., Our study explored the potential drivers of the evolution of winter molts in Nearctic and Western Palearctic breeding passerines. Using phylogenic analysis, we tested whether photoperiod, migration distance, NDVI of the breeding and overwintering grounds, habitat, and diet were associated with species undergoing a winter prebasic molt or a prealternate molt. Our study suggests that the evolution of winter molt strategies in Nearctic and Western Palearctic migratory passerines was likely driven by multiple factors, but photoperiod, migration distance, and overwintering ground conditions are particularly important.

Habitat selectivity has become an increasingly acknowledged mechanism shaping the structure of freshwater communities; however, most studies have focused on the effect of predators and competitors, neglecting habitat complexity and specialization. In this study, we examined the habitat selection of semiaquatic (amphibians: Bufonidae; odonates: Libellulidae) and aquatic organisms (true bugs: Notonectidae; diving beetles: Dytiscidae). From each family, we selected one habitat generalist species able to coexist with fish (Bufo bufo, Sympetrum sanguineum, Notonecta glauca, Dytiscus marginalis) and one species specialized in fishless habitats (Bufotes viridis, Sympetrum danae, Notonecta obliqua, Acilius sulcatus). In a mesocosm experiment, we quantified habitat selection decisions in response to the non-consumptive presence of fish (Carassius auratus) and vegetation structure mimicking different successional stages of aquatic habitats (no macrophytes; submerged and floating macrophytes; submerged, floating, and littoral-emergent macrophytes). No congruence between habitat specialists and generalists was observed, but a similar response to fish and vegetation structure defined both semiaquatic and aquatic organisms. While semiaquatic generalists did not distinguish between fish and fishless pools, specialists avoided fish-occupied pools and had a preferred vegetation structure. In aquatic taxa, predator presence affected habitat selection only in combination with vegetation structure, and all species preferred fishless pools with floating and submerged macrophytes. Fish presence triggered avoidance only in the generalist bug N. glauca. Our results highlight the significance of habitat selectivity for structuring freshwater ecosystems and illustrate how habitat selection responses to a top predator are dictated by specialization and life history.