A protected and warningly coloured butterfly can become a muellerian mimic of another species in two steps: (i) a major mutation converts the pattern of the less protected species to an approximate resemblance of the better protected (one-way convergence); (ii) after the spread of this mutant, the species, which now resemble each other sufficiently to be mistaken one for the other by predators, undergo mutual convergence, using whatever major or minor genetic variation is available to them. Although sometimes one or other step might occur alone, in general early theorists were mistaken in attributing muellerian mimicry to only one of these processes. By hybridizing races of Heliconius melpomene and races of H. erato (a pair of parallel mimetic species from the neotropics, held in mutual muellerian mimicry across wide inter-racial variations in colour pattern) we have shown that, as expected from the two-step theory, the races differ at a number (two to nine) of genetic loci, usually unlinked or loosely linked, including at least one mutant of major effect in each case. We describe the genetic constitution of eight races of H. melpomene (for 11 loci affecting colour pattern) and of eight races of H. erato (for up to 15 loci), and have started to identify the linkage groups. Map distances for those loci that are linked range from around 0.3 to zero in males, with no recombination in females. Muellerian mimicry is expected to produce total uniformity of pattern: universal exceptions to this are the existence of distinct mimicry rings flying within the same habitat, geographical variation within nearly all the more widespread species (divergence in the face of normalizing selection), and, in a few species, polymorphism or sexual dimorphism. Sympatric mimicry rings will, according to the two-step model of evolution, persist indefinitely if their patterns are so distinct that under no circumstances do predators mistake one for the other. Gradual mutual convergence is then impossible, although members of a weakly protected mimicry ring that can produce a mutation giving sufficient initial resemblance to a better protected ring can still be captured by it. Batesian mimics promote this by lowering the protection of the ring that they belong to, but their models can escape only in this way as normalizing selection prevents their gradual evolution away from the batesian mimic. If the rings are too distinct in pattern even this capture of species becomes impossible as no single mutant is able to bridge the gap between the two patterns, and the necessary two mutations will be extremely unlikely to occur together. The five principal sympatric mimicry rings of the mature neotropical rain forests are very distinct in their appearance The capture of a species by another ring can produce geographical variation both in the species captured and in the capturing ring, whose pattern is somewhat altered by mutual convergence with the captured species in the second step of the evolution of the muellerian resemblance. We suggest that the striking differences between the races within H. melpomene, H. erato and other Heliconius species resulted from these effects of inter-ring capture. Distributional evidence suggests that this chiefly occurred in refuges formed by the contraction of the neotropical rain forests during the cool dry periods in the Quaternary; these, by differential extinction of elements of the flora and fauna of different refuges, could have produced long-term changes in the relative abundances of the mimicry rings, and hence (as the protection given to a ring is proportional to its abundance) somewhat different capture events in each refuge. Several existing species confirm that this mode of evolution occurs, by retaining a distinctive pattern in the absence of any other remotely similar species, but becoming mimetic in areas where they encounter a pattern somewhat like their own. The isolated populations of Heliconius hermathena show this particularly clearly; the effect can be discerned also in H. melpomene and H. erato . Although polymorphism in muellerian mimics is largely unexplained, in two species of Heliconius it may result from the existence of two or more similar but slightly differing ‘sub-rings’ among their comimics in the family Ithomiidae, which show both spatial and temporal heterogeneity in their local distribution, which apparently is able to maintain a polymorphic equilibrium in the more uniformly distributed Heliconius . We have tentatively reconstructed the ancestral patterns of H. melpomene and erato by two independent methods: first, as dominant genes are much more likely to be incorporated than recessive ones during changes of pattern, the phenotype produced by the recessive alleles at all the known loci will be close to the ancestral pattern; secondly, species that are becoming mimics evolve more than those that are not, so that non-mimetic relatives of melpomene and erato will have a pattern close to ancestral. Both methods suggest, for both species, that the ancestor was a black butterfly with yellow (or possibly white) bars, and it may be that melpomene and erato have been comimics for a very long time. Previous climatic cycles in the Quaternary have apparently caused full speciation within two mutually mimetic evolving lineages, producing pairs of parallel mimetic species within the genus, of which melpomene and erato constitute one pair.

A generic-level phylogeny for the butterfly family Nymphalidae was produced by cladistic analysis of 234 characters from all life stages. The 95 species in the matrix (selected from the 213 studied) represent all important recognized lineages within this family. The analysis showed the taxa grouping into six main lineages. The basal branch is the Libytheinae, with the Danainae and Ithomiinae on the next branch. The remaining lineages are grouped into two main branches: the Heliconiinae-Nymphalinae, primarily flower-visitors (but including the fruit-attracted Coeini); and the Limenitidinae (sensu strictu), Biblidinae, and the satyroid lineage (Apaturinae, Charaxinae, Biinae, Calinaginae, Morphinae, Brassolinae, and Satyrinae), primarily fruit-attracted. Data partitions showed that the two data sets (immatures and adults) are very different, and a partitioned Bremer support analysis showed that the adult characters are the main source of conflict in the nodes of the combined analysis tree. This phylogeny includes the widest taxon coverage of any morphological study on Nymphalid butterflies to date, and supports the monophyly and relationships of most presently recognized subgroups, providing strong evidence for the presently accepted phylogenetic scheme.

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Plant specific insect herbivores are remarkable not only in their ability to locate and identify the appropriate host, but also in that they very often show a "botanical instinct" (Brues, 1920(Brues, , 1924: closely related insects choose closely related plants.For both insects and plants this statement holds true primarily at the level of higher taxa, and is an outcome of chemical similarities among related botanical groups (Kusnezov, 1929).The generation of higher level taxonomic correlations between insects and their host plants is thought to be due to concurrent evolution. A hypothesis as to just how coevolution between insects and plants in the past resulted in these present day patterns was suggested by Brues (1920) and developed fully by Ehrlich and Raven (1965) on the basis of butterfly host plant data. The model involves adaptive radiation by plant lines which evolve effective herbivore deterrents, followed by adaptive

The Atlantic Forest region (wide sense) includes very complex tropical environments, increasingly threatened by extensive anthropogenic conversion (>90%). Ecologically specialized, short-generation insects (butterflies) are evaluated here as indicators for monitoring community richness, landscape integrity, and sustainable resource use in the region. The > 2100 butterfly species in the Atlantic Forest region have been censused in many sites over 35 years, giving comparable daily, weekly, monthly, and long-term site lists. The 21 most thoroughly studied sites include 218-914 species, of which half can be censused in a week or less. The butterfly communities are divided into six relatively distinct faunal regions, centered in the northeast, the central coastal tablelands, the southeast coastal plain, the mountains plus interior of the southeastern states, thc central plateau, and the southern states. Species richness shows the highest values in coastal mountains from 15 to 23"s. Local butterfly communities show a high turnover, with 20 to 40 percent of the species, especially small Lycaenidae and Hesperiidae, recorded only as unstable populations or "tourists." Easily sampled species in the family Nymphalidae, and especially its bait-attracted subfamilies, are best correlated with the entire butterfly fauna and can bc used as surrogates for species diversity. In most butterfly groups, species richness is well predicted by landscape connectivity alone, or by composite indices of environmental heterogeneity, natural disturbance, and (negatively) anthropogenic disturbance. Principal components and redundancy analyses showed that the richness and proportions of different butterfly groups in the local fauna are variably explained by disturbance, seasonality, temperature, vegetation, soils, and landscape connectivity. Various groups thus can be used as rapid indicators of different types of change in the community, its environment, and the landscape. Threatened and rare species also can be used as indicators of the most unique Atlantic Forest communities (paleoenvironments), which need special attention. RESUMOA regizo da Mata Atlintica latu sensu inclui ambientes tropicais muito complexos, cada vez mais ameagados por extensa convers%o antr6pica (>90%). Insetos pequenos, especializados, e de ciclo ripido (borboletas) sPo avaliados neste trabalho como indicadores para o monitoramento da riqueza de comunidades, integridade de paisagens, e us0 sustentivel de recursos na regido. As >2100 espCcies de borboletas na regido da Mata Atlhntica t&m sido recenseadas em muitos sitios durante 0s Liltimos 35 anos, dando listas compariveis diirias, semanais, mensais e totais para cada sitio. 0 s 21 sitios mais intensivamente estudados incluem 218-914 espCcies, das quais metade pode ser amostrada em uma semana ou menos. As comunidades de borboletas sdo divididas em seis subregibes faunisticas relativamente distintas, centradas no nordeste, nos tabuleiros baianos, no litoral do sudeste, nas regi6es montanhosas no interior dos estados do s...