Bees Associated with Linden (Tilia spp.) Trees and their Susceptibility to Toxic Sugars in Nectar

Bees provide critical pollination services to diverse agricultural crops, native plants and trees. Globally, there are reports of bee declines which have been attributed to diseases, exposure to pesticides and changes in land use that are believed to have led to a reduction in foraging resources and nesting habitats for native bees. Other factors such as low nectar production caused by water stress in plants or toxins present in nectar may also be responsible but have received little attention. Risks associated with foraging behaviors are particularly critical as bees spend considerable time seeking food resources. Linden, a common ornamental tree in urban areas, produces an abundance of nectar and pollen, and thus benefits bees. However, in the late 1970's, dead bees were observed under linden in Europe when environmental conditions were dry. European researchers speculated that the causal factor was the presence of the sugar mannose in linden nectar under drought stress. Mannose is similar in structure to glucose which is used by bees as a carbohydrate source. The toxicity of mannose was believed to be due to disruption of glucose metabolism resulting from competition between mannose and glucose for the enzyme hexokinase during the glycolysis cycle that provides energy for bees. In laboratory studies mannose and galactose were shown to be toxic to honey bees. Their impacts on bumble bees were, however, not determined. There is little information available about the associations of bees with linden in the USA. Occasionally dead bumble bees have been observed under linden trees in western Oregon in the west coast of the USA. The current study was conducted to: 1) Examine bloom and nectar production in linden, correlate nectar production with environmental conditions, and with diversity and abundance of foragers; and 2) Determine the impacts of mannose and galactose on honey bees and bumble bees. The study was conducted in 2014 and 2015 in the city of Corvallis in western Oregon. Honey bees, five species of bumble bees, solitary bees (Halictus spp.), yellow jackets and dipterans (primarily syrphids), visited four species of linden surveyed during bloom. Honey bees were the dominant foragers, and accounted for 69% of foragers in 2014 and 84% in 2015. Nectar production in linden flowers was highest in the morning, and was positively correlated with relative humidity and negatively with temperature. However, there was no correlation between nectar production and the abundance of foragers over both years. A preliminary HPLC analysis of linden nectar samples collected from three linden trees showed a peak with the same retention time as a mannose standard. Further analyses are needed for confirmation of the presence of mannose in the nectar of linden. In a laboratory bioassay, mannose and galactose were toxic to both honey bees and bumble bees. However, when the toxic sugars were presented to honey bees and bumble bees in combination with the non-toxic glucose, the toxic impact was significantly lower (p< 0.05) if the proportion of glucose was high (90%) compared to combinations with lower proportions (10% or 50%) of glucose. These results provide support for the hypothesis that mortality of bees when exposed to mannose is due to competition with glucose for the hexokinase enzyme during glycolysis. However, it is still not known why higher bumble bees have been reported to die after foraging on linden when honey bees are the dominant foragers on linden, and are susceptible to the toxicity of mannose. It is possible that honey bees and bumble bees differ in their ability to assess the presence of toxins in nectar or that other factors are involved. Further research is needed for determining differences, if any, in the foraging behaviors of honey bees and bumble bees on linden trees, and for detecting other nectar compounds in linden that may differ in their impacts on different species of bees

Interacciones Ecológicas de la familia Membracidae (Hemiptera, Auchenorryncha) dentro de claros de bosque de la Amazonía Ecuatoriana y notas sobre su historia natural

Dentro de un ecosistema los organismos interactúan entre sí creando conexiones que serán las responsables de mantener en equilibrio el ecosistema. Un ejemplo de interacción es la relación multitrófica Formicidae-Membracidae-planta hospedera. Se ha estudiado esta interacción a tres niveles en claros de bosque naturales y artificiales en un intento por averiguar si existen diferencias en estas interacciones entre estos dos tipos de hábitat. Adicionalmente, se intenta evaluar algún patrón en la dinámica poblacional de ciertas especies de membrácidos y, determinar si existe algún grado de especialismo en la relación multitrófica. Para esto, se analizaron variables físicas (área, luminosidad, cobertura vegetal) y biológicas (diversidad) de cada tipo de claro de bosque. Se realizaron censos mensuales de 400 poblaciones de 74 especies de membrácidos distribuidos en 11 claros de bosque durante un año (2008-2009) y se registraron sus interacciones con hormigas mutualistas y plantas hospederas. Para analizar las diferencias entre claros de bosque naturales y artificiales se realizaron correlaciones entre las variables físicas, un análisis no paramétrico de similaridad (ANOSIM) y un análisis de escalamiento dimensional no métrico (NMDS)

Plan de intervención de Enfermería en el deterioro cognitivo del adulto mayor de la Casa Hogar San José, ciudad de Ibarra, provincia de Imbabura.2015.

Implementar un plan de intervención de enfermería, en el deterioro cognitivo del Adulto Mayor, en la Casa Hogar San José, 2015.La presente investigación se realizó en la Casa Hogar de Adultos Mayores ¿San José¿ de la ciudad de Ibarra; un estudio de tipo no experimental con enfoque cualitativo porque se recurrió a la observación y recolección de la información para el análisis correlacional, descriptivo, trasversal y retrospectivo, sin manipulación de las variables. Se utilizó la técnica de la revisión documental de historias clínicas para obtener información de los antecedentes patológicos de los trece adultos mayores que residen en esta Casa Hogar; y, el Cuestionario de Estado Mental Portátil de Pfeiffer (SPMSQ) con 10 ítems, validado por la Dra. Adriana Quinga, Post gradista en Geriatría del hospital San Vicente de Paúl, para conocer el nivel de deterioro cognitivo de cada adulto mayor sujeto de investigación. La información obtenida permitió concluir que el 23,08% posee deterioro cognitivo leve, el 15,38% posee deterioro cognitivo moderado y un 46,15% deterioro cognitivo severo, el 15, 38% restante de los adultos mayores no aplicaron el test por presentar discapacidad intelectual y lingüística. La revisión bibliográfica que incorpora el marco teórico de la investigación, permite establecer que los adultos mayores atraviesan por un proceso degenerativo de sus funciones cerebrales superiores que provoca un deterioro fisiológico, psicológico y social, que es posible causa de dependencia funcional. Como alternativa de solución se propone la creación de un plan de intervención de enfermería con siete terapias que permitieron la activación, recuperación y rehabilitación de las funciones cerebrales superiores de los adultos mayores, promovieron la creatividad, la imaginación, concentración y organización; las terapias manuales incrementaron la fuerza muscular y flexibilidad así como la amplitud de movimientos y destrezas. La investigación también permitió valorar la actitud y aptitud del personal que labora en la casa hogar, en la atención directa y personalizada a los adultos mayores, así como una adecuada asistencia sanitaria, tomando en cuenta sus dificultades y discapacidades. Se socializó el procedimiento de atención para la correcta aplicación de las terapias descritas en el plan de intervención, con el personal responsable, buscando el desenvolvimiento autonómico y la ejecución de actividades instrumentales de los Adultos Mayores, para disminuir la dependencia del cuidador.Licenciatur

Rapid ant community reassembly in a Neotropical forest: Recovery dynamics and land‐use legacy

Regrowing secondary forests dominate tropical regions today, and a mechanistic understanding of their recovery dynamics provides important insights for conservation. In particular, land‐use legacy effects on the fauna have rarely been investigated. One of the most ecologically dominant and functionally important animal groups in tropical forests are the ants. Here, we investigated the recovery of ant communities in a forest–agricultural habitat mosaic in the Ecuadorian Chocó region. We used a replicated chronosequence of previously used cacao plantations and pastures with 1–34 years of regeneration time to study the recovery dynamics of species communities and functional diversity across the two land‐use legacies. We compared two independent components of responses on these community properties: resistance, which is measured as the proportion of an initial property that remains following the disturbance; and resilience, which is the rate of recovery relative to its loss. We found that compositional and trait structure similarity to old‐growth forest communities increased with regeneration age, whereas ant species richness remained always at a high level along the chronosequence. Land‐use legacies influenced species composition, with former cacao plantations showing higher resemblance to old‐growth forests than former pastures along the chronosequence. While resistance was low for species composition and high for species richness and traits, all community properties had similarly high resilience. In essence, our results show that ant communities of the Chocó recovery rapidly, with former cacao reaching predicted old‐growth forest community levels after 21 years and pastures after 29 years. Recovery in this community was faster than reported from other ecosystems and was likely facilitated by the low‐intensity farming in agricultural sites and their proximity to old‐growth forest remnants. Our study indicates the great recovery potential for this otherwise highly threatened biodiversity hotspot

Hunting habits die hard: Conserved prey preferences in army ants across two distant neotropical rainforests

Army ants are widely recognized as keystone species in neotropical rainforests due to their role as important arthropod predators. Their large‐scale raids involve thousands of workers scouring the forest floor in pursuit of prey, primarily capturing other invertebrates. Up to 20 species of army ants coexist in a rainforest, and dietary niche differentiation has been proposed as a mechanism to alleviate competition among them. Based on only a handful of study sites, however, our understanding of the precise dietary preferences and the extent of niche differentiation remains notably limited. In this study, we aimed to expand our knowledge of army ant communities by resolving an Ecuadorian predation network consisting of 244 prey species and 13 army ant species representing the five known neotropical army ant genera: Cheliomyrmex, Eciton, Labidus, Neivamyrmex, and Nomamyrmex. We collected 2156 prey items from 180 army ant raids/emigrations, and of these, we identified 1945 prey items to the family level, 1313 to the genus level, and 664 to the species level based on morphological identifications and DNA barcodes. Prey consisted primarily of other ants (1843 prey items; 153 ant species), to the largest part ant brood (N = 1726). Hence, most army ant species chiefly plundered the nests of other ants, while the three swarm raiding species, that is, Lab. praedator, Lab. spininodis, and Ec. burchellii, exhibited a relatively high proportion of non‐ant invertebrate prey in their diet. The predation network showed a high degree of specialization (H2′ = 0.65), characterized by little dietary niche overlap among sympatric species. We compared the Ecuadorian network with one previously studied in Costa Rica and found that, despite the large geographic distance, prey preferences remained remarkably similar. We discovered species‐specific preferences for captured ant genera and species, despite some species turnover in both army ants and prey. Additionally, army ants also exhibited consistent spatiotemporal raiding preferences across study sites. In conclusion, predation preferences within army ant communities exhibited consistency in multiple niche dimensions across two distant neotropical rainforests, suggesting a notable level of predictability within army ant predation networks

Stratification and recovery time jointly shape ant functional reassembly in a Neotropical forest

1. Microhabitat differentiation of species communities such as vertical stratification in tropical forests contributes to species coexistence and thus biodiversity. However, little is known about how the extent of stratification changes during forest recovery and influences community reassembly. Environmental filtering determines community reassembly in time (succession) and in space (stratification), hence functional and phylogenetic composition of species communities are highly dynamic. It is poorly understood if and how these two concurrent filters - forest recovery and stratification - interact. 2. In a tropical forest chronosequence in Ecuador spanning 34 years of natural recovery, we investigated the recovery trajectory of ant communities in three overlapping strata (ground, leaf litter, lower tree trunk) by quantifying 13 traits, as well as the functional and phylogenetic diversity of the ants. We expected that functional and phylogenetic diversity would increase with recovery time and that each ant community within each stratum would show a distinct functional reassembly. We predicted that traits related to ant diet would show divergent trajectories reflecting an increase in niche differentiation with recovery time. On the other hand, traits related to the abiotic environment were predicted to show convergent trajectories due to a more similar microclimate across strata with increasing recovery age. 3. Most of the functional traits and the phylogenetic diversity of the ants were clearly stratified, confirming previous findings. However, neither functional nor phylogenetic diversity increased with recovery time. Community-weighted trait means had complex relationships to recovery time and the majority were shaped by a statistical interaction between recovery time and stratum, confirming our expectations. However, most trait trajectories converged among strata with increasing recovery time regardless of whether they were related to ant diet or environmental conditions. 4. We confirm the hypothesized interaction among environmental filters during the functional reassembly in tropical forests. Communities in individual strata respond differently to recovery, and possible filter mechanisms likely arise from both abiotic (e.g., microclimate) and biotic (e.g., diet) conditions. Since vertical stratification is prevalent across animal and plant taxa, our results highlight the importance of stratum-specific analysis in dynamic ecosystems and may generalize beyond ants

Rapid ant community reassembly in a Neotropical forest: Recovery dynamics and land-use legacy

Regrowing secondary forests dominate tropical regions today, and a mechanistic understanding of their recovery dynamics provides important insights for conservation. In particular, land-use legacy effects on the fauna have rarely been investigated. One of the most ecologically dominant and functionally important animal groups in tropical forests are ants. Here, we investigated the recovery of ant communities in a forest - agricultural habitat mosaic in the Ecuadorian Chocó region. We used a replicated chronosequence of previously used cacao plantations and pastures with 1 - 34 years of regeneration time to study the recovery dynamics of species communities and functional diversity across the two land use legacies. We compared two independent components of responses on these community properties: resistance, which is measured as the proportion of an initial property that remains following the disturbance; and resilience, which is the rate of recovery relative to its loss. We found that compositional and trait structure similarity to old-growth forest communities increased with regeneration age, whereas ant species richness remained always at a high level along the chronosequence. Land-use legacies influenced species composition, with former cacao plantations showing higher resemblance to old-growth forests than former pastures along the chronosequence. While resistance was low for species composition and high for species richness and traits, all community properties had similarly high resilience. In essence, our results show that ant communities of the Chocó recovery rapidly, with former cacao reaching predicted old-growth forest community levels after 21 years and pastures after 29 years. Recovery in this community was faster than reported from other ecosystems and was likely facilitated by the low-intensity farming in agricultural sites and their proximity to old-growth forest remnants. Our study indicates the great recovery potential for this otherwise highly threatened biodiversity hotspot

Odontomachus davidsoni sp. nov. (Hymenoptera, Formicidae), a new conspicuous trap-jaw ant from Ecuador

One of the largest species in its genus, Hoenle, Lattke & Donoso, is described from workers and queens collected at lowland forests in the Chocó-Darién bioregion in coastal Ecuador. The workers are characterized by their uniform red coloration, their large size (16-18 mm body length), and their frontal head striation that reaches the occipital margin. DNA barcodes (COI) and high resolution 2D images of the type material are provided, as well as an updated key for the Neotropical species of . In addition, a three-dimensional digital model of the worker holotype and a paratype queen scanned with DISC3D based on photogrammetry is presented, for the first time in a species description. Findings of large and conspicuous new species are uncommon around the world and suggest that these Ecuadorian rainforests may conceal many more natural treasures that deserve conservation