Biology subjects

Souto-Vilaros, D.

Publications and source records attributed to Souto-Vilaros, D..

3 recordsLinked to original sources

bioRxiv2025

Nectar yeast scent additions fail to impact overall bouquet composition and bumble bee visitation in a montane herb

Premise of researchThe factors that mediate how foragers locate food supplies are of vital importance in understanding their energy acquisition and survival. Microbes that inhabit floral nectar can play outsized roles in altering nectar chemistry and nutrition, thereby affecting floral visitors. MethodologyHere, we consider one such nectar microbe, the cosmopolitan, specialist nectar yeast, Metschnikowia reukaufii (Metschnikowiaceae), by inoculating a nectar analog of the subalpine wildflower, Corydalis caseana ssp. brandegeei (Fumariaceae), and then characterizing the yeasts impacts on floral scent composition and the foraging behavior of its main pollinator, Bombus appositus (Apidae). We assessed foraging behavior of B. appositus in a flower array near the Rocky Mountain Biological Laboratory (Colorado, USA) to test the hypothesis that foragers preferentially visit yeast-inoculated flowers over sterile controls. Additionally, we assessed whether bees spent more time at, and fed more quickly on, yeast-inoculated flowers. In a separate experiment, we tested whether Corydalis inflorescences inoculated with M. reukaufii had different scent bouquets than sterile inflorescences. Pivotal resultsWe found that bumble bee pollinators showed no preference for the focal yeast species, with inoculated nectar having no effect on number of flowers visited, time spent on individual flowers, or time spent accessing nectar. Further, the overall scent bouquet compositions of yeast-inoculated Corydalis inflorescences were not statistically significantly different than those of sterile inflorescences, despite increased emissions of several volatiles that are known to be produced by M. reukaufii. ConclusionsOur findings suggest that B. appositus does not respond to the presence of M. reukaufii in the nectar of Corydalis, and instead, yeast-associated volatile emissions may serve as a reliable cue of a nectar reward that is unused by these pollinators. These findings suggest a few avenues for future research, particularly how morphologically complex, highly scented flowers interact with VOCs produced by nectar-inhabiting microbes, and how floral visitors interpret these signals.

ecology↗

bioRxiv2025

The magnitude of cryptic insect diversity in one tropical rainforest

O_LICryptic species represent significant entities in conservation planning and are common among tropical insects. Many studies focusing on cryptic species have been restricted to a narrow taxon and it is not clear whether some insect clades or assemblages may have a greater propensity for cryptic speciation than others. Here, we contrast cryptic diversity among 22 insect assemblages surveyed on Barro Colorado Island (BCI), a tropical rainforest in Panama. C_LIO_LICryptic species were defined as externally indistinguishable from their sister species but with a different barcode index number. We detected 214 cryptic species out of a total of 2,006 species studied (10.6%). The percentage of cryptic species varied greatly among assemblages (0-19%), with half of assemblages devoid of cryptic species, and the highest proportions of cryptics in Pieridae and Formicidae. C_LIO_LIThe percentage of cryptic species was weakly influenced by phylogeny and it was best explained by the local number of species and an index of taxonomic knowledge. Cryptic species were distinguished by an average distance divergence in sequence of 9%, but their ecological characteristics remain unclear. C_LIO_LIAsymptotic estimates indicated that 11.4% of species studied on BCI may be cryptic. Since many of the species-rich insect assemblages occurring on BCI were not considered in this study, this estimate probably represents a lower bound to the true cryptic insect richness on BCI. C_LIO_LIThis significant contribution to biodiversity should not be ignored and, because of apparent low population levels, may be particularly vulnerable to land use and climate changes. C_LI

evolutionary biology↗

bioRxiv2020

Spatiotemporal shifts in the role of floral traits in shaping tropical plant-pollinator interactions

The pollination syndrome hypothesis predicts that plants pollinated by the same pollinator group bear convergent combinations of specific floral traits. Nevertheless, some studies have shown relatively low predictive power for these floral trait combinations. This discrepancy may be caused by changes in the importance of specific floral traits for shaping interactions under different environmental conditions and for different pollinator groups. To test this, we studied pollination systems and floral traits along an elevational gradient on Mount Cameroon during wet and dry seasons. Using Random Forest models, allowing the ranking of traits by significance, we demonstrated that some floral traits are more important than others in shaping interactions and that these traits predict pollinators relatively well. However, the distribution and importance of traits varies under different environmental conditions. Our results imply the need to improve our trait-based understanding of plant-pollinator interactions to better inform the debate surrounding pollination syndrome hypothesis.

ecology↗