Drosophila antonietae is an endemic South American cactophilic species found in relictual xerophytic vegetation, mostly associated with Cereus hildmaniannus cactus. Low differentiation among populations of this species has been detected using several markers. In this work, we performed an allozyme genetic variability analysis of 11 natural populations of D. antonietae and included a discussion about the possible influences of several evolutionary processes that might be acting to maintain the pattern observed. The genetic variability of 14 isoenzyme loci was analysed and showed a high genetic diversity (average observed heterozygosity ¼ 0.319) and a moderate genetic differentiation among populations (F statistics ¼ 0.0723). A correlation between genetic and geographical and ecological distances was detected among pairs of populations and the regional equilibrium analysis was thus applied. This analysis resulted in Nm (number of migrants) of approximately 3.21, indicating that moderate levels of both gene flow and genetic drift occur in this species, with gene flow overlapping genetic drift. However, considering ecological features of drosophilids, we propose a hypothesis to explain the moderate differentiation encountered as a result of three different processes, or a combination of them: (1) gene flow; (2) a short period of differentiation, i.e. maintenance of ancestral polymorphism; and (3) action of natural selection. Moreover, if gene flow is present, the high genetic diversity compared with other cactophilic and non-cactophilic species could be due to differential selection in different populations followed by gene exchange among them. These factors are discussed in the light of D. antonietaeÕs historical and evolutionary association with the host cactus.

In an allozyme electrophoresis survey of 15 hypostomine species from the Itaipu Hydroelectric Reservoir, 25 loci from 14 enzyme systems were scored. Allozyme data allowed recording diagnostic genetic markers for all species analyzed and for some species groups within Hypostomus, a taxon which is taxonomically still unresolved in the Upper Rio Paraná basin. The mean expected heterozygosity of the species was considerably variable and hypotheses to tentatively explain this variation are discussed. A cladogram based upon the allelic frequencies of the species analyzed was produced by the continuous maximum likelihood method: Rhinelepis aspera and M. parananus were separated from the species of Hypostominae by a long branch length. Pterygoplichthys anisitsi was the sister of all the representatives of the genus Hypostomus. Within Hypostomus, two main clades were produced: in the first, H. cochliodon was the sister of the species comprising the H. plecostomus group, and in the second, the tree showed the following relationships: (H. albopunctatus (H. regani + Hypostomus sp. 3) + (H. margaritifer (H. microstomus (Hypostomus sp. 1 (H. ternetzi + Hypostomus sp. 2)). Hypostomus ternetzi and Hypostomus sp. 2 are referred to here as representatives of the H. ternetzi group.

The genus Drosophila is the most abundant in the Drosophilidae family. some species are endemic to certain regions and others are cosmopolitans. in Brazil, there are several ecosystems to explore regarding the composition and ecological aspects of Drosophila. xerophytic areas are an example. They can be found in the south and southeast of Brazil as islands, a result of paleoclimatic cycle changes. The aim of the present work is to provide information about the composition of the Drosophila community in eight xerophytic areas (where the cactus Cereus hildmaniannus occurs) in the south and southeast of Brazil. This work is an important step in the study of quantitative ecological aspects of the Drosophila community in xerophytic areas that form continental islands in the neotropical region. The composition of the Drosophila community which was found is compatible with previous work in several aspects. The ecological indexes showed a possible positive association between diversity and the degree of preservation of the studied areas. são paulo state communities presented the highest similarity among the sites tested, although no statistical significant correlation between the Jaccard index and geographical distance was found using the mantel test. Keywords

RBE 57 1-6 Revista Brasileira de Entomologia xxx (2015) xxx-xxx w w w . r b e n t o m o l o g i a . c o m a b s t r a c tThe population dynamics of a species tends to change from the core to the periphery of its distribution. Therefore, one could expect peripheral populations to be subject to a higher level of stress than more central populations (the center-periphery hypothesis) and consequently should present a higher level of fluctuating asymmetry. To test these predictions we study asymmetry in wing shape of five populations of Drosophila antonietae collected throughout the distribution of the species using fluctuating asymmetry as a proxy for developmental instability. More specifically, we addressed the following questions: (1) what types of asymmetry occur in populations of D. antonietae? (2) Does the level of fluctuating asymmetry vary among populations? (3) Does peripheral populations have a higher fluctuating asymmetry level than central populations? We used 12 anatomical landmarks to quantify patterns of asymmetry in wing shape in five populations of D. antonietae within the framework of geometric morphometrics. Net asymmetry -a composite measure of directional asymmetry + fluctuating asymmetry -varied significantly among populations. However, once net asymmetry of each population is decomposed into directional asymmetry and fluctuating asymmetry, most of the variation in asymmetry was explained by directional asymmetry alone, suggesting that populations of D. antonietae have the same magnitude of fluctuating asymmetry throughout the geographical distribution of the species. We hypothesize that larval development in rotting cladodes might play an important role in explaining our results. In addition, our study underscores the importance of understanding the interplay between the biology of a species and its geographical patterns of asymmetry.

Flies from the Drosophilidae family are model organisms for biological studies and are often suggested as bioindicators of environmental quality. The Araucaria Forest, one of Atlantic Forest phyto-physiognomy, displays a highly fragmented distribution due to the expansion of agriculture and urbanization. Thus, this work aimed to evaluate and compare the drosophilid assemblages from two highland Araucaria Forest fragments, one a conservation unit (PMA -Parque Municipal das Araucárias) and the other a private property without any conservational policy (FBL -Fazenda Brandalise), in space and time, using species abundances and richness, ecological indexes and Neotropical and exotic species proportions as parameters to establish the level of environmental quality of these fragments. Our results showed that the observed diversity in PMA (H' = 2.221) was approximately 40% higher than in FBL (H' = 1.592). This could be due to higher preservation quality and habitat diversity in PMA, indicating the importance of conservation units. However, richness were similar for these areas, with PMA (D mg = 6.602) only 8% higher than FBL (D mg = 6.128), which suggest that the larger distance from city limits and the larger size of FBL forested area could be compensating the higher disturbance caused by antrophic extractive exploitation of this fragment. This points out that, besides the quality of presevertion, the size and/or connection with other fragments should be considered for areas destined for biodiversity conservation. In general, both areas presented similar drosophilid assemblages, and the expressive abundance of both Neotropical species (mostly of the subgroup willistoni) and the exotic species D. kikkawai suggests that these areas are in intermediate stages of conservation.Keywords: ecological indexes, Mixed Ombrophylous Forest, exotic species, Drosophila, Atlantic Forest, Neotropical region. Comparação das assembleias de Drosophilidae (Diptera) de dois fragmentos de floresta de araucária de altitude, com e sem políticas de conservação ambiental ResumoMoscas da família Drosophilidae são organismos modelo para estudos biológicos e frequentemente sugeridas como bioindicadoras da qualidade ambiental. A Mata de Araucária, uma das fitofisionomias da Mata Atlântica, apresenta-se altamente fragmentada devido a expansão da agricultura e da urbanização. Assim, este trabalho teve como objetivo avaliar e comparar as assembleias de drosofilídeos de dois fragmentos de Mata de Araucária de altitude, uma área de preservação (PMA -Parque Municipal das Araucárias) e uma propriedade particular e sem política de conservação (FBL -Fazenda Brandalise), no tempo e no espaço, utilizando abundâncias e riquezas das espécies, índices ecológicos e proporções de espécies neotropicais e espécies exóticas como parâmetros para estabelecer o nível de qualidade ambiental destes fragmentos. Nossos resultados mostraram que a diversidade observada em PMA (H' = 2,221) foi 40% maior do que em FBL (H' = 1,592). Isto pode ser devido a maior qualidade ...