Cruising the rain forest floor: butterfly wing shape evolution and gliding in ground effect.

Flight is a key innovation in the evolutionary success of insects and essential to dispersal, territoriality, courtship and oviposition. Wing shape influences flight performance and selection likely acts to maximize performance for conducting essential behaviours that in turn results in the evolution of wing shape. As wing shape also contributes to fitness, optimal shapes for particular flight behaviours can be assessed with aerodynamic predictions and placed in an ecomorphological context. Butterflies in the tribe Haeterini (Nymphalidae) are conspicuous members of understorey faunas in lowland Neotropical forests. Field observations indicate that the five genera in this clade differ in flight height and behaviour: four use gliding flight at the forest floor level, and one utilizes flapping flight above the forest floor. Nonetheless, the association of ground level gliding flight behaviour and wing shape has never been investigated in this or any other butterfly group. We used landmark-based geometric morphometrics to test whether wing shapes in Haeterini and their close relatives reflected observed flight behaviours. Four genera of Haeterini and some distantly related Satyrinae showed significant correspondence between wing shape and theoretical expectations in performance trade-offs that we attribute to selection for gliding in ground effect. Forewing shape differed between sexes for all taxa, and male wing shapes were aerodynamically more efficient for gliding flight than corresponding females. This suggests selection acts differentially on male and female wing shapes, reinforcing the idea that sex-specific flight behaviours contribute to the evolution of sexual dimorphism. Our study indicates that wing shapes in Haeterini butterflies evolved in response to habitat-specific flight behaviours, namely gliding in ground effect along the forest floor, resulting in ecomorphological partitions of taxa in morphospace. The convergent flight behaviour and wing morphology between tribes of Satyrinae suggest that the flight environment may offset phylogenetic constraints. Overall, this study provides a basis for exploring similar patterns of wing shape evolution in other taxa that glide in ground effect.

Phylogenetic relationships of Hamadryas (Nymphalidae: Biblidinae) based on the combined analysis of morphological and molecular data.

A new phylogenetic hypothesis for the Neotropical butterfly genus Hamadryas, based on the combination of a morphological matrix, one mitochondrial (COI) and four nuclear markers (CAD, RpS5, EF1a, and Wingless), is presented. Results from analyses of the molecular evidence are compared with a previously published morphological phylogeny. Molecular data and the analysis of the complete dataset support the monophyly of Hamadryas and most sister groups suggested by morphological data alone. The addition of DNA sequences to the morphological matrix helped define species groups for which no morphological synapomorphies were found. Partitioned Bremer support indicates that COI, CAD, and morphology were consistently in agreement with the combined evidence tree. In contrast, signal from the nuclear markers Rps5, EF1a, and Wingless showed indifference at most levels of the tree, and minor conflict at nodes solving the relationships between species groups. Though resolved, the combined evidence tree shows low resample values, particularly among species groups whose relationships were characterized by short internodes. A reassessment about the pattern of character change for sound production is presented and discussed.

Revised species definitions and nomenclature of the blue and purple/rose Cithaerias/ butterflies (Lepidoptera, Nymphalidae, Satyrinae).

This study reassesses the taxonomic status of Neotropical blue and purple/rose-colored Cithaerias butterflies, thus complementing a previous study of the rose-colored species. Based on comparative study of wing coloration and genitalia morphology, I revise species definitions and the taxonomic status of: Cithaerias andromeda, C. azurina STAT. REV., C. esmeralda STAT. REV., C. bandusia STAT. REV., C. pyropina, and C. songoana STAT. REV. Photographs of adults and illustrations of male and female genitalia are provided for all species. Of particular importance are the genitalia illustrations of male and female C. azurina, presented here for the first time, as well as finding a putative first female of Ecuadorean subspecies C. pyropina julia.

Phylogeny of Amathusiini butterflies based on adult morphology (Lepidoptera, Nymphalidae, Satyrinae).

Based on comparative morphology of adults, a phylogeny is proposed for the butterfly tribe Amathusiini (Nymphalidae, Satyrinae). The dataset includes 92 characters scored for 45 species in 12 genera, representing the most comprehensive phylogenetic analysis for this group. Parsimony analyses produced a well-resolved strict consensus tree where genera were divided in three main groups: (clade 1) Stichophthalma; (clade 2) Aemona, Faunis, Melanocyma and Taenaris; (clade 3) Enispe, Discophora, Thaumantis, Thauria, Amathusia, Amathuxidia, and Zeuxidia. While genera in clades 1 and 2 were found to be morphologically homogeneous, clade 3 showed remarkable morphological divergence between and within genera. The monophyly of most genera was recovered with variable levels of support, but Melanocyma and Taenaris nested within Faunis. Therefore, here Melanocyma NEW SYN. is subsumed within Faunis, and Taenaris STAT. REV. is regarded as a subgenus of Faunis. Mimicry likely evolved a single time within the Faunis-Taenaris assemblage, as species of Taenaris formed a monophyletic group. Results are compared to early classifications and recent DNA-based analyses, and points of agreement and conflicts are discussed.

Conserved ancestral tropical niche but different continental histories explain the latitudinal diversity gradient in brush-footed butterflies.

The global increase in species richness toward the tropics across continents and taxonomic groups, referred to as the latitudinal diversity gradient, stimulated the formulation of many hypotheses to explain the underlying mechanisms of this pattern. We evaluate several of these hypotheses to explain spatial diversity patterns in a butterfly family, the Nymphalidae, by assessing the contributions of speciation, extinction, and dispersal, and also the extent to which these processes differ among regions at the same latitude. We generate a time-calibrated phylogeny containing 2,866 nymphalid species (~45% of extant diversity). Neither speciation nor extinction rate variations consistently explain the latitudinal diversity gradient among regions because temporal diversification dynamics differ greatly across longitude. The Neotropical diversity results from low extinction rates, not high speciation rates, and biotic interchanges with other regions are rare. Southeast Asia is also characterized by a low speciation rate but, unlike the Neotropics, is the main source of dispersal events through time. Our results suggest that global climate change throughout the Cenozoic, combined with tropical niche conservatism, played a major role in generating the modern latitudinal diversity gradient of nymphalid butterflies.

Vertical distribution, flight behaviour and evolution of wing morphology in Morpho butterflies.

1. Flight is a key innovation in the evolution of insects that is crucial to their dispersal, migration, territoriality, courtship and predator avoidance. Male butterflies have characteristic territoriality and courtship flight behaviours, and females use a characteristic flight behaviour when searching for host plants. This implies that selection acts on wing morphology to maximize flight performance for conducting important behaviours among sexes. 2. Butterflies in the genus Morpho are obvious components of neotropical forests, and many observations indicate that they show two broad categories of flight behaviour and flight height. Although species can be categorized as using gliding or flapping flight, and flying at either canopy or understorey height, the association of flight behaviour and flight height with wing shape evolution has never been explored. 3. Two clades within Morpho differ in flight behaviour and height. Males and females of one clade inhabit the forest understorey and use flapping flight, whereas in the other clade, males use gliding flight at canopy level and females use flapping flight in both canopy and understorey. 4. We used independent contrasts to answer whether wing shape is associated with flight behaviour and height. Given a single switch to canopy habitation and gliding flight, we compared contrasts for the node at which the switch to canopy flight occurred with the distribution of values in the two focal clades. We found significant changes in wing shape at the transition to canopy flight only in males, and no change in size for either sex. A second node within the canopy clade suggests that other factors may also be involved in wing shape evolution. Our results reinforce the hypothesis that natural selection acts differently on male and female butterfly wing shape and indicate that the transition to canopy flight cannot explain all wing shape diversity in Morpho. 5. This study provides a starting point for characterizing evolution of wing morphology in forest butterflies in the contexts of habitat selection and flight behaviour. Further, these observations suggest that exploring wing shape evolution for canopy and understorey species in other insects may help understand the effects of habitat destruction on biological diversity.

The early stages and natural history of Antirrhea adoptive porphyrosticta (Watkins, 1928) in eastern ecuador (Lepidoptera: Nymphalidae: Morphinae).

Here we describe the immature stages and ecological associations of Antirrhea adoptiva porphyrosticta Watkins, 1928 (Lepidoptera:Nymphalidae:Morphinae). The cloud forest bamboo, Chusquea scandens Kunth (Bambusoidea: Poaceae), serves as the larval food plant for this butterfly in eastern Ecuador, the first hostplant record for Antirrhea outside the family Arecaceae. The larvae of A. adoptiva porphyrosticta are superficially similar to those of other Antirrhea species. We also provide observations on adult and larval behavior. Caterpillars of this butterfly species are parasitized by tachinid flies, as well as by Ichneumonidae and a newly described braconid wasp.

Large-Scale Climate Effects Meet an Amazonian Butterfly: Which Population Parameters Respond to El Niño?

One of the most tangible outcomes of climate change is change in the frequency of El Niño/La Niña events. They have a large impact on rainfall in the Western hemisphere, but their impact on tropical fauna is largely unknown. A decade long capture-mark-recapture study of the widespread Ecuadorian butterfly Nessaea hewitsoni (Felder & Felder) from an intact forest allowed us to analyze patterns of monthly and seasonal population dynamics before, during, and after an El Niño event. El Niño events did not affect long-term population size, but a 5-month delayed El Niño led to temporary emigration of females, with their subsequent return. Increased rainfall correlated with reduced survival in both sexes, but this effect was twice as strong in females. This investigation is the longest, continuous population study on any Neotropical insect species. Though we sampled on a modest scale, the magnitude of El Niño events suggests that our findings likely reflect insect population responses across a much larger portion of Amazonian forests. This study underscores the importance of analyzing multiple, interacting population parameters beyond local abundance in order to understand the biotic responses to El Niño and climate change in tropical systems. Had our analyses not included temporary emigration, no effect would have been detected because El Niño did not affect local population abundance.

Documenting diversity in the Amazonian butterfly genus Bia (Lepidoptera, Nymphalidae).

A comparative study of over 1,000 specimens allowed us to revise the taxonomy of the Amazonian butterfly genus Bia. We redescribed the genus, and used a selected set of characters to define and describe new species and subspecific taxa. We found that male genitalia showed little variation among taxa, and that wing and genitalia characters varied independently across the range of the genus. We also noted that species diversification seems to follow a north-south Amazonian divide, with Bia actorion and decaerulea occupying the northern portion of the genus range while the remaining four species are found in southern Amazonia. As defined here Bia includes six species: B. actorion (Linnaeus), B. actorion ecuatoria DeVries & Penz, NEW SSP., B. actorion occulta Casagrande & Penz, NEW SSP., B. decaerulea Weymer STAT. NOV., B. decaerulea cayana Simonsen & Penz, NEW SSP., B. decaerulea pallida Casagrande & Penz, NEW SSP., B. rebeli Bryk STAT. NOV., B. rebeli aegina Penz & Simonsen, NEW SSP., B. rebeli acreana Casagrande & Penz, NEW SSP., B. rebeli arikeme Penz & Casagrande, NEW SSP., B. rebeli pareci Penz & DeVries, NEW SSP., B. rebeli cuprea Penz & Casagrande, NEW SSP., B. rebeli tapajos Penz & Simonsen, NEW SSP., B. caelestis Penz & DeVries, NEW SP., B. pucallpa Casagrande & Penz, NEW SP., and B. peruana Röber.

Revised species definitions and nomenclature of the rose colored Cithaerias butterflies (Lepidoptera, Nymphalidae, Satyrinae).

This study provides updated species definitions for five rose-colored Cithaerias butterflies, starting with a historical overview of their taxonomy. Given their mostly transparent wings, genitalia morphology yielded the most reliable characters for species definition and identification. Genitalic divergence is more pronounced when multiple species occur in sympatry than between parapatric taxa. Cithaerias aurorina is granted full species status, C. cliftoni is reinstated as a full species, and one new combination is proposed, i.e. C. aurora tambopata. Two new synonyms are proposed, Callitaera phantoma and Callitaera aura = Cithaerias aurora. 

An illustrated key to male Actinote from Southeastern Brazil (Lepidoptera, Nymphalidae) / Chave ilustrada para machos de Actinote do sudeste do Brasil (Lepidoptera, Nymphalidae)

In certain times of the year, Actinote butterflies can be vastly abundant in Southeastern Brazil, thus representing conspicuous denizens of our fauna. Their wing coloration allows for the recognition of five major patterns, which probably resulted from mimicry. Furthermore, examination of series of field-collected and reared specimens clearly demonstrates a high intra-specific variation in wing color pattern. In concert, inter-specific resemblance (mimicry) and intra-specific variation make it difficult to discriminate Actinote species from each other. This key aims at providing a tool for identification of male Actinote. To that effect, we provide diagnostic characters and illustrations of wings and male genitalia for 22 species. We hope that the clear identification of these species will lead to the discovery of species yet unrecognized in Southeastern Brazil.

Em certas épocas do ano, as borboletas do gênero Actinote podem ser muito abundantes no sudeste do Brasil, constituindo, então, elementos conspícuous da nossa fauna. Sua coloração alar permite a separação em cinco padrões básicos, provavelmente relacionados com o mimetismo. Além disso, séries de exemplares coletados no campo ou criados em laboratório demonstram claramente que existe uma grande variabilidade intra-específica na coloração alar destas borboletas. Em conjunto, a semelhança entre as espécies (mimetismo) e variação intra-específica dificultam o reconhecimento das espécies de Actinote. Esta chave tem como objetivo auxiliar a identificação dos machos destas borboletas e, para tanto, são apresentados caracteres diagnósticos, ilustrações das asas e genitália de 22 espécies. Esperamos que a clara identificação destas espécies possa revelar a presença de espécies ainda não reconhecidas no sudeste do Brasil.