Kerteszia Theobald (Diptera: Culicidae) mosquitoes and bromeliads: A landscape ecology approach regarding two species in the Atlantic rainforest.

On the ecological scale of an organism, a homogeneous geographical landscape can represent a mosaic of heterogeneous landscapes. The bionomy of Kerteszia mosquitoes can contribute to foundation landscape ecology by virtue of in the role of the configuration and composition of the habitat played in the distribution of mosquito species. Thus, this study aimed: to compare the abundance of Kerteszia in dense tropical rainforest, restinga and rural area, to assess the bioecological characteristics of the main bromeliads hosting Kerteszia, and to associate the bioecological arrangement of the bromeliads with Kerteszia distribution. Field collections were conducted in a monthly schedule from December of 2010 to November 2011. The vegetation of landscapes was characterized on the basis of a digital cartographic database, the manual of the Brazilian vegetation, environmental atlas information, satellite images and visits to the sites. Multivariate generalized linear models were employed using the R-project statistical program. The results were: Anopheles cruzii was the most frequent species in dense tropical rainforest (67.42%), with a positive association (deviance=25.8; P=0.002). Anopheles bellator was more abundant in the Restinga area (78.97%), with a positive association (deviance=10.4, P=0.018). There was a positive aggregation of Restinga with An. bellator (RR=2.42) but a lower level with An. cruzii (RR=0.31). Thus we can conclude that landscape characteristics influence the distribution of Kerteszia mosquitoes. An. bellator has a higher prevalence in Restinga areas, whereas An. cruzii was the most prevalent in the dense tropical rainforest.

Correlation between populations of Rhodnius and presence of palm trees as risk factors for the emergence of Chagas disease in Amazon region, Brazil.

Among the states that comprise the legally defined Amazon region of Brazil, Pará has presented the highest occurrences of acute cases of Chagas disease over the last two decades. These cases have been attributed to consumption of fruits from native palm trees. In surveys in rural and wild areas of the municipality of Oriximiná, Pará, triatomine fauna, their main ecotopes and the infection rate due to Trypanosoma cruzi were identified using active and passive search methods: manual capture and Noireau traps, respectively. A total of 582 ecotopes were surveyed using 1496 Noireau traps. Out of 442 specimens collected, 289 were identified as Rhodnius robustus and 153 as Rhodnius pictipes. The infection rate caused by T. cruzi was 17.4%. The food sources of the triatomines were found to be birds, hemolymph, horses, and rodents. The association between R. robustus and inajá palm trees (Attalea marita), which are abundant in rural areas, was confirmed. On the other hand, R. pictipes is found in several palm tree species, such as inajá (A. marita), mucajá (Acrocomia aculeata), murumuru (Astrocaryum murumuru) and patauá (Oenocarpus bataua), and in bromeliads in wild areas. These occurrences of triatomine species in regions with or without T. cruzi infection, in the vicinity of the main settlement of the municipality, suggest that there is a need for entomological and epidemiological surveillance in this region.

Spider-fed bromeliads: seasonal and interspecific variation in plant performance.

BACKGROUND AND AIMS: Several animals that live on bromeliads can contribute to plant nutrition through nitrogen provisioning (digestive mutualism). The bromeliad-living spider Psecas chapoda (Salticidae) inhabits and breeds on Bromelia balansae in regions of South America, but in specific regions can also appear on Ananas comosus (pineapple) plantations and Aechmea distichantha. METHODS: Using isotopic and physiological methods in greenhouse experiments, the role of labelled ((15)N) spider faeces and Drosophila melanogaster flies in the nutrition and growth of each host plant was evaluated, as well as seasonal variation in the importance of this digestive mutualism. KEY RESULTS: Spiders contributed 0·6 ± 0·2 % (mean ± s.e.; dry season) to 2·7 ± 1 % (wet season) to the total nitrogen in B. balansae, 2·4 ± 0·4 % (dry) to 4·1 ± 0·3 % (wet) in An. comosus and 3·8 ± 0·4 % (dry) to 5 ± 1 % (wet) in Ae. distichantha. In contrast, flies did not contribute to the nutrition of these bromeliads. Chlorophylls and carotenoid concentrations did not differ among treatments. Plants that received faeces had higher soluble protein concentrations and leaf growth (RGR) only during the wet season. CONCLUSIONS: These results indicate that the mutualism between spiders and bromeliads is seasonally restricted, generating a conditional outcome. There was interspecific variation in nutrient uptake, probably related to each species' performance and photosynthetic pathways. Whereas B. balansae seems to use nitrogen for growth, Ae. distichantha apparently stores nitrogen for stressful nutritional conditions. Bromeliads absorbed more nitrogen coming from spider faeces than from flies, reinforcing the beneficial role played by predators in these digestive mutualisms.

Diversidade de bromélias epífitas na Reserva Particular do Patrimônio Natural Serra do Teimoso, Jussari, BA / Diversity of epiphytic bromeliads in the Reserva Particular do Patrimônio Natural Serra do Teimoso, Jussari, BA

Vascular epiphytes are frequent in mesic habitats and mid-elevation regions. The present study investigated the diversity and species composition of epiphytic bromeliads in the Natural Reserve of Serra do Teimoso (RNST) located in a transitional area between ombrophilous and semideciduous forests. Adapted from the "Rapid and Representative Sampling of Vascular and Non-vascular epiphyte Diversity of Tropical Rain Forests" protocol, our survey method used eight phorophytes of Cariniana legalis (Martius) Kuntze found between 284 and 573 m a.s.l.. We registered 19 morphospecies and 526 bromeliad groups. Almost one third of the species were classified as widely distributed and 27.3% are endemic to southern Bahia. Shannon index was 2.2 nats.ind-1 and the estimated number of species in this area was 25 (SD = ± 3.5). Most C. legalis harbored a similar abundance and species composition of epiphytes, which was dominated by Hohenbergia and Aechmea species. This study registered the occurrence of three species that are new to the state of Bahia, and one genus was collected for the first time in the RNST. Results are in accordance with the known pattern of lower epiphytic diversity in drier locations. Since all new records are exclusive to the crowns of large trees, the sampling of these new records was only possible because climbing techniques were used. Compared to other methodologies for floristic surveys, the one employed here demanded lower sample effort and yielded similar results. Large trees play an important role for epiphytes due to the concentration of species and individuals on them. Thus, the utilization of canopy methodologies in other field surveys would be desirable to sample appropriately epiphytes in large trees.