Philip J. DeVries

The Butterflies of Costa Rica and Their Natural History: Papilionidae, Pieridae, Nymphalidae.

The Description for this book, The Butterflies of Costa Rica and Their Natural History, Volume I: Papilionidae, Pieridae, Nymphalidae, will be forthcoming.

Species diversity in spatial and temporal dimensions of fruit-feeding butterflies from two Ecuadorian rainforests

To test the hypotheses that butterflies in an intact lowland rainforest are randomly distributed in space and time, a guild of nymphalid butterflies was sampled at monthly intervals for one year by trapping 883 individuals of 91 species in the canopy and understory of four contiguous, intact forest plots and one naturally occurring lake edge. The overall species abundance distribution was well described by a log-normal distribution. Total species diversity (c-diversity) was partitioned into additive components within and among community subdivisions (a-diversity and b-diversity) in vertical, horizontal and temporal dimensions. Although community subdivisions showed high similarity (1-b-diversity/c-diversity), significant b-diversity existed in each dimension. Individual abundance and observed species richness were lower in the canopy than in the understory, but rarefaction analysis suggested that the underlying species richness was similar in both canopy and understory. Observed species richness varied among four contiguous forest plots, and was lowest in the lake edge plot. Rarefaction and species accumulation curves showed that one forest plot and the lake edge had significantly lower species richness than other forest plots. Within any given month, only a small fraction of total sample species richness was represented by a single plot and height (canopy or understory). Comparison of this study to a similar one done in disturbed forest showed that butterfly diversity at a naturally occurring lake edge differed strongly from a pasture-forest edge. Further comparison showed that species abundance distributions from intact and disturbed forest areas had variances that differed significantly, suggesting that in addition to extrapolation, rarefaction and species accumulation techniques, the shapes of species abundance distributions are fundamental to assessing diversity among sites. This study shows the necessity for long-term sampling of diverse communities in space and time to assess tropical insect diversity among different areas, and the need of such studies is discussed in relation to tropical ecology and quick surveys in conservation biology.

Analyzing Spatial Structure of Communities Using the Two‐Dimensional Poisson Lognormal Species Abundance Model

The joint spatial and temporal fluctuations in the community structure of tropical butterflies are analyzed by fitting the bivariate Poisson lognormal distribution to a large number of observations in space and time. By applying multivariate dependent diffusions for describing the fluctuations in the abundances, the environmental variance is estimated to be very large and so is the strength of local density regulation. The variance in the lognormal species abundance distribution is partitioned into components expressing the heterogeneity between the species, independent noise components for the different species, a demographic stochastic component, and a component due to overdispersion in the sampling. In disagreement with the neutral theory, the estimates show that the heterogeneity component is the dominating one, representing 81% of the total variance in the lognormal model. Different spatial components of diversity, the alpha, beta, and gamma diversity, are also estimated. The spatial scale of the autocorrelation function for the community is of order 1 km, while sampling of a quadrat would need to be 10 km on a side to yield the total diversity for the community.

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 systematic position of Antirrhea and Caerois, with comments on the classification of the Nymphalidae (Lepidoptera)

Based on a Wagner tree analysis of ninety‐two characters (eighty‐five larval, one egg, six adult), the nymphalid butterfly genera Antirrhea and Caerois are demonstrated to be the closest relatives of the genus Morpho. Accordingly, Antirrhea and Caerois are formally transferred from the Satyrinae to the Morphinae. Without these two genera, the Morphinae (sensu Ehrlich) is at best a paraphyletic group. During the study, fourteen nymphalid genera were treated as potential outgroups. The analysis suggests that many currently accepted higher taxa within the Nymphalidae are probably untenable: the Satyrinae and Nymphalinae (sensu Ehrlich) are both probably polyphyletic; the Biinae (sensu Miller) must be abandoned, being polyphyletic; the Charaxidae (sensu Rydon), although probably monophyletic, appear to form a group subordinate to part of the ‘Satyrinae’; and Apatura does not cluster with the ‘Nymphalinae’, but appears to form the sister‐group of the ‘Satyrinae’ (less Antirrhea and Caerois) plus the Charaxinae. Re‐analyses of reduced data sets, in which potentially homoplasious larval head‐horn and adult wing venational characters were eliminated, leaves these conclusions essentially unaltered. The authors suggest that a solution to the seemingly intractable problem posed by nymphalid higher classification can be sought by the application of cladistic analysis to a large data set gathered from all developmental stages, with special emphasis on detailed comparative larval morphology.

Similarity and difference among rainforest fruit‐feeding butterfly communities in Central and South America

1. Documenting species abundance distributions in natural environments is critical to ecology and conservation biology. Tropical forest insect faunas vary in space and time, and these partitions can differ in their contribution to overall species diversity. 2. In the Neotropics, the Central American butterfly fauna is best known in terms of general natural history, but butterfly community diversity is best documented by studies on South American fruit-feeding butterflies. Here, we present the first long-term study of fruit-feeding nymphalid species diversity from Central America and provide a unique comparison between Central and South American butterfly communities. 3. This study used 60 months of sampling among multiple spatial and temporal partitions to assess species diversity in a Costa Rican rainforest butterfly community. Abundance distributions varied significantly at the species and higher taxonomic group levels, and canopy and understorey samples were found to be composed of distinct species assemblages. 4. Strong similarities in patterns of species diversity were found between this study and one from Ecuador; yet, there was an important difference in how species richness was distributed in vertical space. In contrast to the Ecuadorian site, Costa Rica had significantly higher canopy richness and lower understorey richness. 5. This study affirms that long-term sampling is vital to understanding tropical insect species abundance distributions and points to potential differences in vertical structure among Central and South American forest insect communities that need to be explored.

Phylogenetic Analysis of Morpho Butterflies (Nymphalidae, Morphinae): Implications for Classification and Natural History

Abstract The classification of butterflies in the widely recognized genus Morpho previously used subgenera that were assumed to constitute natural species groups. Cladistic analysis of 120 characters provided a well-resolved tree showing that some subgenera do not constitute monophyletic groups. This study supported some traditional taxonomic species groupings, but rejected the concept of subgenera for Morpho. Therefore, we formally redefined the genus to be consonant with the assumptions of phylogenetic classification. Predictions about Morpho life histories, the correlation of color pattern and flight behavior with vertical flight height, and the evolution of sexual dimorphism are discussed in light of our phylogeny.

Ancient Neotropical origin and recent recolonisation: Phylogeny, biogeography and diversification of the Riodinidae (Lepidoptera: Papilionoidea)

We present the first dated higher-level phylogenetic and biogeographic analysis of the butterfly family Riodinidae. This family is distributed worldwide, but more than 90% of the c. 1500 species are found in the Neotropics, while the c. 120 Old World species are concentrated in the Southeast Asian tropics, with minor Afrotropical and Australasian tropical radiations, and few temperate species. Morphologically based higher classification is partly unresolved, with genera incompletely assigned to tribes. Using 3666bp from one mitochondrial and four nuclear markers for each of 23 outgroups and 178 riodinid taxa representing all subfamilies, tribes and subtribes, and 98 out of 145 described genera of riodinids, we estimate that Riodinidae split from Lycaenidae about 96Mya in the mid-Cretaceous and started to diversify about 81Mya. The Riodinidae are monophyletic and originated in the Neotropics, most likely in lowland proto-Amazonia. Neither the subfamily Euselasiinae nor the Nemeobiinae are monophyletic as currently constituted. The enigmatic, monotypic Neotropical genera Styx and Corrachia (most recently treated in Euselasiinae: Corrachiini) are highly supported as derived taxa in the Old World Nemeobiinae, with dispersal most likely occurring across the Beringia land bridge during the Oligocene. Styx and Corrachia, together with all other nemeobiines, are the only exclusively Primulaceae-feeding riodinids. The steadily increasing proliferation of the Neotropical Riodininae subfamily contrasts with the decrease in diversification in the Old World, and may provide insights into factors influencing the diversification rate of this relatively ancient clade of Neotropical insects.

Estimating Brownian motion dispersal rate, longevity and population density from spatially explicit mark–recapture data on tropical butterflies

1. We develop a Bayesian method for analysing mark-recapture data in continuous habitat using a model in which individuals movement paths are Brownian motions, life spans are exponentially distributed and capture events occur at given instants in time if individuals are within a certain attractive distance of the traps. 2. The joint posterior distribution of the dispersal rate, longevity, trap attraction distances and a number of latent variables representing the unobserved movement paths and time of death of all individuals is computed using Gibbs sampling. 3. An estimate of absolute local population density is obtained simply by dividing the Poisson counts of individuals captured at given points in time by the estimated total attraction area of all traps. Our approach for estimating population density in continuous habitat avoids the need to define an arbitrary effective trapping area that characterized previous mark-recapture methods in continuous habitat. 4. We applied our method to estimate spatial demography parameters in nine species of neotropical butterflies. Path analysis of interspecific variation in demographic parameters and mean wing length revealed a simple network of strong causation. Larger wing length increases dispersal rate, which in turn increases trap attraction distance. However, higher dispersal rate also decreases longevity, thus explaining the surprising observation of a negative correlation between wing length and longevity.

Effects of Salinity on Early Life Stages of the Gulf Coast Toad, Incilius nebulifer (Anura: Bufonidae)

Anuran amphibian populations worldwide are in decline due to a variety of factors including habitat destruction, climate change, disease, introduction of non-native species, and environmental contamination. We conducted a laboratory trial with Incilius nebulifer (synonym: Bufo nebulifer) to determine at what level salinity negatively affects hatching and metamorphosis, and how exposure to salinity during development affects metamorph characteristics that influence adult fitness. Embryos exhibited 95.5–99.5% hatching success at salinities of 0, 2, and 4 parts per thousand (ppt); 74.4% success at 6 ppt; and no hatching at 8 or 10 ppt. Salinity affected hatching success and larval survival, and we found linear trends between higher salinity and lower fractions of hatched embryos and living larvae. The odds of hatching were about the same for 0, 2, and 4 ppt, significantly lower for 6 ppt, and zero for 8 and 10 ppt. The odds of survival to metamorphosis were significantly lower in 6 ppt relative to 0, 2, and 4 ppt combined. Time to metamorphosis, mass, and hind limb length of recent metamorphs showed significant differences among treatment groups, with salinity having large effects on these variables. Development time was longer, mass was lower, and hind limb length was shorter in the 0 and 2 ppt treatments compared to 4 or 6 ppt. We showed that salinity affected the survival of early life stages of Incilius nebulifer and characteristics that have been linked to adult fitness. Our study suggests that low levels of salinity may affect the survival and fitness of other anurans.