Ancient butterfly-ant symbiosis: direct evidence from Dominican amber

Although symbiotic association with ants is pervasive in the butterfly families Lycaenidae and Riodinidae the age of these symbioses has never been estimated explicitly. Here we report the first known fossil riodinid caterpillar. This fossil can be dated minimally between 15 and 20 Ma old, and confidently placed in the extant genus Theope. Differing little from modern day Theope, this fossil from Dominican amber provides direct evidence that secretory and acoustical organs used by modern caterpillars to mediate symbioses with ants have been highly developed at least since the Miocene. This fossil therefore becomes the point of reference for future studies using molecular clock methods for dating these symbioses within the riodinid butterflies. Modern evidence, and the abundance of dolichoderine ants in Dominican amber (now extinct in the West Indies) imply that specialized symbiotic relationships between Theope caterpillars and these ants were likely in existence at least 15 Ma ago. The current distribution of neotropical riodinid butterfly and ant faunas indicates the extinction in the West Indies of at least two unrelated taxa that formed a tightly linked symbiotic association, which persisted to the present elsewhere. <br>     

The phylogeography of Amazonia revisited: new evidence from riodinid butterflies

Abstract A fully resolved cladogram for 19 species in the Charis cleonus group of riodinid butterflies, which have closely parapatric ranges throughout the Amazon basin, is used to derive an area cladogram for the region. This represents the first comprehensive species‐level analysis using insects and results in a hypothesis of Amazonian area relationships that is the most detailed to date. The Charis area cladogram is interpreted as supporting an historical vicariant split between the Guianas and the remainder of the Amazon and then between the upper and lower Amazon. The latter two clades can be further divided into the six most widely recognized areas of endemism and even smaller endemic centers within these, some of which, especially along the Madeira and lower Amazon Rivers, have never been previously hypothesized for butterflies. The overall pattern of historical interrelationships indicated is Guiana + ((Rondônia + (Pará+ Belém)) + (Imeri + (Napo + Inambari))). The area relationships for riodinid butterflies show substantial congruence with those presented from the literature for amphibians, reptiles, birds, primates, rodents, and marsupials, suggesting a common vicariant history for these organisms. A summary area cladogram generated by combining area cladograms for all the aforementioned groups of organisms indicated the pattern of historical interrelationships to be (Guiana + (Rondônia + (Pará+ Belém))) + (Imeri + (Napo + Inambari)). Charis cleonus group species distributions are noticeably larger around the upland periphery of Amazonia and smaller in the central and lower regions. A significant positive correlation between the proportion of range area above 100 m and total range size for each species is used to suggest that past sea‐level rises may explain smaller range sizes in low‐lying regions and that riverine barriers have been important in shaping the current distribution of C. cleonus group species.     

中国蝴蝶新种新亚种及新记录种(IV)(鳞翅目)

记述斑蝶科 1新种、1新记录种 ;蚬蝶科 2新种、3新亚种。所有模式标本均保存在西北农林科技大学昆虫博物馆。     

Gene duplication is an evolutionary mechanism for expanding spectral diversity in the long-wavelength photopigments of butterflies

Butterfly long-wavelength (L) photopigments are interesting for comparative studies of adaptive evolution because of the tremendous phenotypic variation that exists in their wavelength of peak absorbance (lambda(max) value). Here we present a comprehensive survey of L photopigment variation by measuring lambda(max) in 12 nymphalid and 1 riodinid species using epi-microspectrophotometry. Together with previous data, we find that L photopigment lambda(max) varies from 510-565 nm in 22 nymphalids, with an even broader 505- to 600-nm range in riodinids. We then surveyed the L opsin genes for which lambda(max) values are available as well as from related taxa and found 2 instances of L opsin gene duplication within nymphalids, in Hermeuptychia hermes and Amathusia phidippus, and 1 instance within riodinids, in the metalmark butterfly Apodemia mormo. Using maximum parsimony and maximum likelihood ancestral state reconstructions to map the evolution of spectral shifts within the L photopigments of nymphalids, we estimate the ancestral pigment had a lambda(max) = 540 nm +/- 10 nm standard error and that blueshifts in wavelength have occurred at least 4 times within the family. We used ancestral state reconstructions to investigate the importance of several amino acid substitutions (Ile17Met, Ala64Ser, Asn70Ser, and Ser137Ala) previously shown to have evolved under positive selection that are correlated with blue spectral shifts. These reconstructions suggest that the Ala64Ser substitution has indeed occurred along the newly identified blueshifted L photopigment lineages. Substitutions at the other 3 sites may also be involved in the functional diversification of L photopigments. Our data strongly suggest that there are limits to the evolution of L photopigment spectral shifts among species with only one L opsin gene and that opsin gene duplication broadens the potential range of lambda(max) values.     

The larval ant-organs of Thisbe irenea (Lepidoptera: Riodinidae) and their effects upon attending ants

Observations and experiments are presented on the use oflarval ant-organs by the riodinid butterfly Thisbe irenea with emphasis on their function in myrmecophily. The results indicate that each ant organ plays a distinct role in larval-ant association and that all influence the behaviour of attending ants. Interpretations of the roles that lycaenid larval organs play in ant associations are evaluated and discussed in light of myrmecophilous riodinids. Finally, an 'enticement and binding' process, involving the concerted use of the larval organs, is proposed as the behavioural mechanism that T. irenea and other riodinid larvae use to secure the attentions of individual ants for extended periods of time.     

CLIMBER: Climatic niche characteristics of the butterflies in Europe

Detailed information on species’ ecological niche characteristics that can be related to declines and extinctions is indispensable for a better understanding of the relationship between the occurrence and performance of wild species and their environment and, moreover, for an improved assessment of the impacts of global change. Knowledge on species characteristics such as habitat requirements is already available in the ecological literature for butterflies, but information about their climatic requirements is still lacking. Here we present a unique dataset on the climatic niche characteristics of 397 European butterflies representing 91% of the European species (see Appendix). These characteristics were obtained by combining detailed information on butterfly distributions in Europe (which also led to the ‘Distribution Atlas of Butterflies in Europe’) and the corresponding climatic conditions. The presented dataset comprises information for the position and breadth of the following climatic niche characteristics: mean annual temperature, range in annual temperature, growing degree days, annual precipitation sum, range in annual precipitation and soil water content. The climatic niche position is indicated by the median and mean value for each climate variable across a species’ range, accompanied by the 95% confidence interval for the mean and the number of grid cells used for calculations. Climatic niche breadth is indicated by the standard deviation and the minimum and maximum values for each climatic variable across a species’ range. Database compilation was based on high quality standards and the data are ready to use for a broad range of applications.It is already evident that the information provided in this dataset is of great relevance for basic and applied ecology. Based on the species temperature index (STI, i.e. the mean temperature value per species), the community temperature index (CTI, i.e. the average STI value across the species in a community) was recently adopted as an indicator of climate change impact on biodiversity by the pan-European framework supporting the Convention on Biological Diversity (Streamlining European Biodiversity Indicators 2010) and has already been used in several scientific publications. The application potential of this database ranges from theoretical aspects such as assessments of past niche evolution or analyses of trait interdependencies to the very applied aspects of measuring, monitoring and projecting historical, ongoing and potential future responses to climate change using butterflies as an indicator.     

Mutualism between Thisbe irenea butterflies and ants, and the role of ant ecology in the evolution of larval-ant associations

A facultative mutualism between the riodinid butterfly Thisbe irenea and the ponerine ant Ectatomma ruidum is described from Panama. Ants protect larvae against attacks of predatory wasps, but not against tachinid parasitoids. Several potential sources of ecological variation affecting the larval survival of Thisbe irenea are noted. A preliminary means of testing the ability of larvae to appease ants is described that may be applied to all butterfly-ant systems. Observations and literature records indicate that ant taxa which tend butterfly larvae are the same taxa that tend extrafloral nectaries and Homoptera. A general hypothesis for the evolution of myrmecophily among butterflies suggests that ant taxa which utilize secretions in their diet are major selective agents for the evolution of the larval ant-organs, and hence, ant-larval mutualisms. This idea is extended to suggest how appeasement of predaceous ant taxa through the use of larval ant-organs can influence an ant-larval relationship, eventually leading to mutualism.