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ABSTRACT The Plant Stress Hypothesis predicts that stressed plants are more attacked by herbivorous insects. In this work, we investigated the influence of light stress on Crotalaria spectabilis Roth (Fabaceae) and on its main herbivore, the moth Utetheisa ornatrix (L., 1758) (Erebidae: Arctiinae). Specifically, we verified whether plants stressed by shading differ from non-stressed plants in terms of productivity, morphological characteristics and water percentage. We also evaluated the performance of moths in stressed and non-stressed plants. Seeds were sown in pots. When the plants reached 50 cm in height, they were randomly divided into two groups: stressed plants (treatment group) and non-stressed plants (control group). The stressed plants were covered by a black mesh, providing 50% of shading. Eight characteristics of stressed and non-stressed C. spectabilis plants were evaluated: height, fresh and dry aerial biomass, number of pods and seeds, leaf hardness, number of trichomes, leaf area, specific leaf mass and percentage of leaf water. Moths were raised individually on leaves of stressed and non-stressed plants and we obtained the larval survival, larval development time, pupal weight and female fecundity. The non-stressed plants had significantly higher percentage of water in the leaves, greater fresh aerial biomass and a higher number of trichomes than the stressed plants. The survival rate was 98% for larvae raised on leaves from stressed plants and 92% on leaves from non-stressed plants. The larval developmental time was significantly shorter and the weight of female pupae significantly higher in non-stressed plants than in stressed plants. Thus, the Plant Stress Hypothesis was only corroborated by two tested variables: number of trichomes (lower in stressed plants) and larval survival (higher in stressed plants). Trichomes are among the main types of plant defenses against herbivory and reducing their number on leaves would make stressed plants more susceptible to attack by moth larvae, a fact corroborated by a greater larval survival. One of the possible explanations for the lack of corroboration of the Plant Stress Hypothesis for most of the variables tested is that other characteristics can be changed under stress conditions, such as the concentration of secondary compounds.

RESUMO Cerca de 50% da diversidade de mariposas Arctiinae do Brasil está no Cerrado. Contudo, a fauna desses insetos é extremamente subamostrada na região norte do bioma, onde localizam-se as áreas de vegetação mais preservadas. Diante disso, este trabalho teve como objetivos descrever a riqueza, abundância, composição e diversidade beta de Arctiinae em diferentes fitofisionomias de cinco Unidades de Conservação localizadas no nordeste do Cerrado. Foram amostradas 83 espécies, das quais quase 78% ocorreram em apenas uma Unidade de Conservação. As localidades com menor grau de preservação apresentaram maior riqueza de espécies, o que pode ser explicado como uma resposta a distúrbios intermediários na paisagem destes locais. As fitofisionomias florestais foram mais ricas em espécies, corroborando a hipótese da heterogeneidade ambiental. De maneira geral, a similaridade da fauna foi baixa tanto entre as Unidades de Conservação quanto entre as fitofisionomias. Inventários mais completos precisam ser feitos a fim de avaliarmos que fatores estão influenciando os padrões de riqueza e composição de Arctiinae nestas localidades de Cerrado e, assim, subsidiar futuras ações de conservação.

Arctiinae moths include nearly 11,000 species worldwide, of which approximately 700 species occur in the Brazilian Cerrado. The aim of this study was to describe the species composition of Arctiinae, as well as the variation in annual and nightly moth activity, in two Cerrado vegetation types. We sampled moths one night per month from September 2008 to June 2009, in the gallery forest and in the cerrado sensu stricto in the Jardim Botânico de Brasília. We collected 395 tiger moths belonging to 65 morphospecies; 74% of the species belonged to the tribe Arctiini and 26% to Lithosiini. Thirty-one species (47.7%) occurred only in the gallery forest, 13 (20%) occurred only in the cerrado sensu stricto, and 21 (32.3%) occurred in both vegetation types. Additionally, we found the greatest species richness between 7:00 p.m. and 8:00 p.m., and these hours were associated with 21 and 22 species, respectively. Most species (51.8%) were active for up to three hours during the night. In general, the species composition differed between the dry and rainy seasons, and the similarity of the fauna also varied hourly. Based on our results, we suggest that rapid inventories of Arctiinae be performed in both rainy and dry seasons, and sampling should be carried out the entire night.

The Cerrado biome is located in the central region of Brazil and consists mainly of savanna vegetation. In this study we assessed the richness of tiger moths (Arctiidae) of the Brazilian Cerrado. Specifically, we 1) assessed species richness in one-degree cells in the biome, 2) identified areas where these moths are poorly known, and 3) tested if similarities in species composition are related to geographical distance in the relatively well-sampled areas. We obtained the data mainly from specimens deposited in museums, but we also included additional information from the literature. We compiled 2,321 records belonging to 723 species. Specimens were recorded in 108 localities distributed in 67 one-degree cells. Species occurring exclusively in one or two one-degree cells represented 64% of the total number of species. Sample effort was not uniform in the biome, as there were very few records in the northern region of the Cerrado. The best-sampled one-degree cell had 239 species. Species assemblages were structured in space with a clear trend of localities near one another presenting more similarities in faunal composition than distant localities. This distance decay in similarity was slightly more pronounced along the longitudinal than along the latitudinal distances. We conclude that the Cerrado still remains poorly inventoried for tiger moths, particularly in its northern portion, where many unrecorded species may be found in the future. Despite of this limited knowledge, the best-sampled region indicates that richness of tiger moths in the Cerrado is comparable to the species-rich forest biomes in the Neotropical region.

Species' geographic ranges are usually considered as basic units in macroecology and biogeography, yet it is still difficult to measure them accurately for many reasons. About 20 years ago, researchers started using local data on species' occurrences to estimate broad scale ranges, thereby establishing the niche modeling approach. However, there are still many problems in model evaluation and application, and one of the solutions is to find a consensus solution among models derived from different mathematical and statistical models for niche modeling, climatic projections and variable combination, all of which are sources of uncertainty during niche modeling. In this paper, we discuss this approach of ensemble forecasting and propose that it can be divided into three phases with increasing levels of complexity. Phase I is the simple combination of maps to achieve a consensual and hopefully conservative solution. In Phase II, differences among the maps used are described by multivariate analyses, and Phase III consists of the quantitative evaluation of the relative magnitude of uncertainties from different sources and their mapping. To illustrate these developments, we analyzed the occurrence data of the tiger moth, Utetheisa ornatrix (Lepidoptera, Arctiidae), a Neotropical moth species, and modeled its geographic range in current and future climates.A distribuição geográfica das espécies tem sido considerada como a unidade básica em macroecologia e biogeografia, mas ainda há dificuldades em mensurá-la de forma adequada, por diferentes razões. Há cerca de 20 anos atrás, os pesquisadores começaram a utilizar dados locais da ocorrência das espécies para estimar essas distribuições utilizando modelos de nicho ecológico. Entretanto, ainda há uma série de problemas na avaliação dos modelos e em suas aplicações, e uma das soluções é utilizar um consenso de diferentes modelos, projeções climáticas, cenários de emissão e combinação de variáveis, que são fontes de incerteza durante o processo de modelagem de nicho. Neste artigo nós discutimos essa abordagem de consenso e a dividimos em três fases, com níveis crescentes de complexidade. A Fase I é simplesmente a combinação de mapas e a obtenção e interpretação de um único mapa de consenso. A Fase II envolve a descrição das diferenças entre os mapas utilizando técnicas de análise multidimensional, enquanto que a Fase III consiste em analisar quantitativamente e mapear a magnitude relativa das diferentes fontes de incerteza. A fim de ilustrar essa abordagem, nós analisamos dados de ocorrência de Utetheisa ornatrix (Lepidoptera, Arctiidae), uma mariposa distribuída na região Neotropical, modelando sua distribuição geográfica com base em dados climáticos atuais e projeções de mudança climática.

Climate change leads to species' range shifts, which may end up reducing the effectiveness of protected areas. These deleterious changes in biodiversity may become amplified if they include functionally important species, such as herbivores or pollinators. We evaluated how effective protected areas in the Brazilian Atlantic Forest are in maintaining the diversity of tiger moths (Arctiinae) under climate change. Specifically, we assessed whether protected areas will gain or lose species under climate change and mapped their locations in the Atlantic Forest, in order to assess potential spatial patterns of protected areas that will gain or lose species richness. Comparisons were completed using modeled species occurrence data based on the current and projected climate in 2080. We also built a null model for random allocation of protected areas to identify where reductions in species richness will be more severe than expected. We employed several modern techniques for modeling species' distributions and summarized results using ensembles of models. Our models indicate areas of high species richness in the central and southern regions of the Atlantic Forest both for now and the future. However, we estimate that in 2080 these regions should become climatically unsuitable, decreasing the species' distribution area. Around 4% of species were predicted to become extinct, some of them being endemic to the biome. Estimates of species turnover from current to future climate tended to be high, but these findings are dependent on modeling methods. Our most important results show that only a few protected areas in the southern region of the biome would gain species. Protected areas in semideciduous forests in the western region of the biome would lose more species than expected by the null model employed. Hence, current protected areas are worse off, than just randomly selected areas, at protecting species in the future.