Comparison of Drosophilidae (Diptera) assemblages from two highland Araucaria Forest fragments, with and without environmental conservation policies.

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 (Dmg = 6.602) only 8% higher than FBL (Dmg = 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.

Contrasting patterns of within-species morphological variation in two cactophilic Drosophila species (Diptera: Drosophilidae).

In this work, we investigated the morphological variation of the intromittent male copulatory organ (aedeagus) of specimens from natural populations of two cactophilic Drosophila species distributed in the southeast region of Brazil, Drosophila gouveai Tidon-Sklorz & Sene and Drosophila antonietae Tidon-Sklorz & Sene. It was explored how the within-species variability is arranged for both species, considering their historical and ecological features. Our results showed two distinct aedeagal morphologies for these species, and differences within species were observed only in D. gouveai as specimens could be distinguished by their population origin. In contrast, after size discrepancies correction, this feature was not detected in D. antonietae. The contrasting patterns of intraspecific variation, together with the other features exhibited by these two species, are most likely to be explained by differences in the historical host plant association and distribution and in demographic events, which determined the evolutionary history of these two South American cactophilic Drosophila species.

The Drosophila community in xerophytic vegetations of the upper Parana-Paraguay river basin.

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.

The Drosophila community in xerophytic vegetations of the upper Parana-Paraguay river basin

O gênero Drosophila é o mais abundante da família Drosophilidae. Algumas espécies são endêmicas em certas regiões e outras são cosmopolitas. No Brasil existem diversos ecossistemas a serem explorados a respeito da composição e aspectos ecológicos de Drosophila. Áreas xerofíticas são um exemplo, podendo ser consideradas como ilhas continentais no sul e sudeste do Brasil, resultado de mudanças paleoclimáticas cíclicas. O presente trabalho teve o objetivo de fornecer informação sobre a composição da comunidade de Drosophila em oito áreas xerofíticas (onde o cacto Cereus hildmaniannus ocorre) no sul e sudeste do Brasil. Este trabalho é um passo importante no estudo de aspectos ecológicos quantitativos das comunidades de Drosophila em ilhas de vegetação xerofítica na região Neotropical. De modo geral, a composição das comunidades de Drosophila está de acordo com trabalhos anteriores em diversos aspectos. Os índices ecológicos mostraram uma possível associação positiva da diversidade e o grau de preservação das áreas. As comunidades do estado de São Paulo apresentaram as maiores similaridades entre elas, apesar de não ter sido encontrada correlação estatisticamente significativa entre o índice de Jaccard e distâncias geográficas entre as comunidades, através do teste de Mantel.

Temporal and spatial allozyme variation in the South American cactophilic Drosophila antonietae (Diptera; Drosophilidae).

Drosophila antonietae is an endemic South American cactophilic species that uses Cereus hildmaniannus rotting cladodes as breeding sites. We assessed temporal and spatial intrapopulational allozyme variation of two natural populations. Our results suggest that environmental variation (rain precipitation) is probably influencing allozyme temporal variation. Moreover, it seems that D. antonietae does not have intrapopulation structure and has N(ev) (variance effective size) approximately equal to 83 and N(ec) (number of adult flies that colonize each rotting cladode) = 21. The deficiency of heterozygotes found must be due to null alleles, a temporal Wahlund effect, or selection against heterozygotes. Assortative mating and inbreeding are discarded. This is the first report on allozyme variation in D. antonietae. It gives some insight on intrapopulational genetics through space and time for this species. This is important to understand its general genetic variability and will be essential to future works on the natural history and evolution of this species.