University of Panama

Fluctuating asymmetry (FA) and wing shape variation have been widely proposed as sensitive indicators of developmental instability and environmental stress in insects, yet their temporal dynamics remain poorly explored in tropical systems. In this study, we examined fine-scale temporal and environmental variation in wing FA and shape of the orchid bee Euglossa imperialis Cockerell, 1922 within a tropical dry forest of central Panama. Using geometric morphometrics, we quantified bilateral wing asymmetry and shape variation across monthly sampling periods spanning dry and rainy seasons, integrating high-resolution climatic data. Overall FA values were low and showed no significant differences between seasons, indicating high developmental stability across broad seasonal regimes. Similarly, wing shape exhibited extensive overlap between dry and rainy seasons, with no discrete seasonal differentiation. In contrast, both FA and wing shape varied significantly among months, revealing a gradual and continuous temporal signal. Minimum temperature and relative humidity emerged as the main environmental variables associated with FA, whereas precipitation showed no detectable effect. These results indicate that developmental instability and wing morphology in E. imperialis are primarily shaped by short-term climatic variability rather than by categorical seasonal contrasts. Our findings highlight the importance of fine temporal resolution when evaluating morphological responses to environmental conditions and suggest that FA and wing shape function as scale-dependent indicators of environmental variation. Integrating geometric morphometrics with high-resolution climate data provides a powerful framework for refining the use of orchid bees as bioindicators in tropical ecosystems.

Urbanization decreases habitat availability and leaves small and isolated patches of habitat, surrounded by an urban matrix that hinders dispersal for most organisms. Insects are among the most affected groups in terms of species richness, density, and abundance due to urbanization. Among insects, butterfly communities are often used as indicators because they are highly sensitive to disturbance. To analyze how urbanization affects alpha and beta butterfly diversity in urban forest fragments in Panama City, we studied these communities across dry and rainy seasons and examined their relationship with landscape, habitat, and environmental factors. Sampling involved one transect in each of four tropical urban forest fragments along an urbanization gradient. Butterflies were sampled with entomological nets and bait traps on different sampling dates, while environmental parameters were recorded at meteorological stations within each urban patch on each date. Landscape predictors were obtained from a geographic information system. We recorded a total of 2,192 individuals, belonging to six families, 16 subfamilies, 105 genera, and 142 species. We found that diversity—based on Hill’s numbers—changed significantly among urban forest fragments, while richness remained unchanged. Seasonal comparisons revealed significant turnover of species during the rainy and dry seasons. Butterfly richness and abundances (total, Nymphalidae, and Pieridae) were positively affected by urbanization cover percentage, patch size, and plant richness, while sampling date and temperature have negative impacts on the butterfly community. Finally, Shannon diversity was negatively influenced by urbanization and plant richness, whereas Simpson index responded in the opposite direction to the same factors. Tropical butterfly communities will rely on conserving remaining tropical urban fragments, implementing measures to enhance connectivity, and restoring these green spaces.

Evaluating how tropical tree growth, longevity, wood density and hydraulic functioning vary across environmental gradients is essential to understand forest dynamics and to support species-specific forest management. Here, we address this for a commercially important neotropical tree species: Hymenaea courbaril L. We combined tree-allometry, tree-ring, wood-density and xylem functional-trait data from two seasonally-dry Neotropical vegetation types occurring on contrasting soils under similar annual precipitation: a Cerrado savanna and an Evergreen Forest. Across populations, we found differences in growth and xylem traits consistent with a growth-longevity trade-off. Compared to the Evergreen Forest, Cerrado trees were shorter-lived (maximum age: 78 vs. 171 years), presented a stouter allometry (lower height for a given diameter), and faster juvenile growth rates. Xylem functional traits revealed a contrasting anatomical configuration: under the same carbon density (no wood density differences), Cerrado trees produced xylem that was both hydraulically safer (higher vessel frequency, lower vulnerability index) and more efficient (higher theoretical hydraulic conductivity). At the plot level, soil phosphorus was positively associated with tree growth, whereas soil texture (clay content) correlated with xylem anatomical traits representing hydraulic safety and efficiency. These results suggest that soil properties contribute to shaping both growth patterns and xylem structure, potentially influencing the growth-longevity trade-off. By integrating tree performance, longevity, allometry, wood density and xylem functioning, our results help improve the representation of carbon-storage and-dynamics in tropical forests and can be used to guide sustainable species-specific forest management practices.

The global rise in honey demand has been accompanied by increasing concerns over adulteration and synthetic substitutes, complicating quality control for regulators and importers. The quality and freshness of Apis mellifera honey are widely assessed using indicators such as 5-hydroxymethylfurfural (HMF) content and diastase activity. HMF increases with excessive heating and storage, while diastase activity declines under the same conditions. This study analyzed 140 honey samples from Panama (2022-2024), including artisanal and commercially available products. HMF quantification was performed using a validated solid-phase extraction (SPE) method coupled with ultra-high-performance liquid chromatography with diode array detection (UHPLC-DAD), following ICH guidelines. Diastase activity was measured with the Phadebas® enzymatic method. Validation confirmed excellent specificity, linearity (r2 = 0.9995), precision (RSD < 2.5%), accuracy (98-102% recovery), and sensitivity (LOD = 0.15 µg/mL; LOQ = 0.45 µg/mL). Results showed that 50% of commercial honeys did not meet regulatory limits (HMF ≤ 80 mg/kg; diastase ≥ 8 DN), suggesting inadequate storage, thermal abuse, or adulteration, while most artisanal honey samples complied with national and international standards. These findings provide essential evidence for honey quality monitoring in Panama and highlight the importance of enforcing regulations to safeguard consumers and support authentic local products.

En las últimas décadas, la enseñanza de la Biología ha presentado un desafío considerable ante el creciente fenómeno del negacionismo científico, el cual requiere un pensamiento analítico desde diversas perspectivas educativas para mitigar su influencia en el aula de clase y en el contexto social. Por ello, este ensayo tuvo como objetivo identificar estrategias metodológicas para fomentar el análisis crítico en los docentes, el uso de medios didácticos y el desarrollo de la competencia argumentativa en los estudiantes, que les permitan apropiarse de habilidades para analizar, evaluar y razonar situaciones cotidianas y académicas con un enfoque dialógico. Se realizó una revisión de literatura publicada entre el año 2020 y el 2025, que permitió identificar espacios de aprendizaje mediados por el conocimiento significativo, el juicio fundamentado y la capacidad de diferenciar datos objetivos de conclusiones erróneas o sesgadas. Los resultados mostraron que la enseñanza y el aprendizaje de la Biología en tiempos de negacionismo científico se deben fundamentar desde principios pedagógicos y epistemológicos de la educación, donde el aprendizaje significativo permita conectar el conocimiento con la realidad. De igual forma, es importante una enseñanza crítica que propicie el reconocimiento de sesgos en la construcción de reflexiones propias y el desarrollo de competencias argumentativas como medio para cuestionar y tomar decisiones informadas.