Rapid diversification is often associated with morphological or ecological adaptations that allow organisms to radiate into novel niches. Neotropical Adelpha butterflies, which comprise over 200 species and subspecies, are characterized by extraordinary breadth in host plant use and wing colour patterns compared to their closest relatives. To examine the relationship between phenotypic and species diversification, we reconstructed the phylogenetic history of Adelpha and its temperate sister genus Limenitis using genomewide restriction-site-associated DNA (RAD) sequencing. Despite a declining fraction of shared markers with increasing evolutionary distance, the RAD-Seq data consistently generated well-supported trees using a variety of phylogenetic methods. These well-resolved phylogenies allow the identification of an ecologically important relationship with a toxic host plant family, as well as the confirmation of widespread, convergent wing pattern mimicry throughout the genus. Taken together, our results support the hypothesis that evolutionary innovations in both larvae and adults have permitted the colonization of novel host plants and fuelled adaptive diversification within this large butterfly radiation.

/pdf/rapid-diversification-associated-with-ecological-27csjzkhzc.pdf

Rapid diversification associated with ecological specialization in Neotropical Adelpha butterflies

Ethnopharmacology of Q'eqchi' Maya antiepileptic and anxiolytic plants: effects on the GABAergic system.

Despite more than a century of biological research on the evolution and maintenance of mimetic signals, the relative frequencies of models and mimics necessary to establish and maintain Batesian mimicry in natural populations remain understudied. Here we investigate the frequency-dependent dynamics of imperfect Batesian mimicry, using predation experiments involving artificial butterfly models. We use two geographically distinct populations of Adelpha butterflies that vary in their relative frequencies of a putatively defended model ( Adelpha iphiclus ) and Batesian mimic ( Adelpha serpa ). We found that in Costa Rica, where both species share similar abundances, Batesian mimicry breaks down, and predators more readily attack artificial butterfly models of the presumed mimic, A. serpa . By contrast, in Ecuador, where A. iphiclus (model) is significantly more abundant than A. serpa (mimic), both species are equally protected from predation. Our results provide compelling experimental evidence that imperfect Batesian mimicry is frequency-dependent on the relative abundance of models and mimics in natural populations, and contribute to the growing body of evidence that complex dynamics, such as seasonality or the availability of alternative prey, influence the evolution of mimetic traits.

https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2017.2786

Frequency dependence shapes the adaptive landscape of imperfect Batesian mimicry

Acute and subacute toxicity of the aqueous extract of Alibertia edulis (Rich.) A. Rich. ex DC. in rats.

Adaptive radiation is characterized by rapid diversification that is strongly associated with ecological specialization. However, understanding the evolutionary mechanisms fueling adaptive diversification requires a detailed knowledge of how natural selection acts at multiple life-history stages. Butterflies within the genus Adelpha represent one of the largest and most diverse butterfly lineages in the Neotropics. Although Adelpha species feed on an extraordinary diversity of larval hosts, convergent evolution is widespread in this group, suggesting that selection for mimicry may contribute to adaptive divergence among species. To investigate this hypothesis, we conducted predation studies in Costa Rica using artificial butterfly facsimiles. Specifically, we predicted that nontoxic, palatable Adelpha species that do not feed on host plants in the family Rubiaceae would benefit from sharing a locally convergent wing pattern with the presumably toxic Rubiaceae-feeding species via reduced predation. Contrary to expectations, we found that the presumed mimic was attacked significantly more than its locally convergent model at a frequency paralleling attack rates on both novel and palatable prey. Although these data reveal the first evidence for protection from avian predators by the supposed toxic, Rubiaceae-feeding Adelpha species, we conclude that imprecise mimetic patterns have high costs for Batesian mimics in the tropics.

Complex dynamics underlie the evolution of imperfect wing pattern convergence in butterflies

In an effort to study plants of the Rubiaceae from Panama, 299 herbarium samples, representing 133 species, were subjected to alkaloid screening. From this total, 234 samples (78%) afforded a positive test for alkaloids, and 99 samples (33%) gave a positive reaction for indole alkaloids; 109 species (82%) contain alkaloids and 58 (44%) produce indole alkaloids. This is the first time that 102 (94%) and 52 (90%) species are reported as alkaloid and indole alkaloid bearing, respectively. The results of 10 out of 15 species, that is 67%, corroborate earlier studies. The richest indole alkaloid species were: Hamelia patens, Hamelia xerocarpa, Hoffmannia morii, Hoffmannia unguis-canceris, Deppea grandiflora, Elaeagia nitidifolia, Rondeletia secunda, Simira maxonii, Uncaria tomentosa, Gonzalagunia rosea, Isertia haenkeana, Isertia laevis, Posoqueria latifolia and Cinchona pubescens.

Berenice Castillo

Papers

Alkaloid Screening of Herbarium Samples of Rubiaceae from Panama