The occurrence of mosquitoes in the authoring environment of dairy cattle was verified in southern Rio Grande do Sul. For collection of specimens, it was installed a Magoon trap, in which during a couple of cattle-approximately six months of age was placed. Samples were collected during 24 hours, twice a month for 12 months. After 24 hours, the cattle were removed from the trap and the insects were collected inside the trap, with the aid of glass bottles, containing, cotton soaked in acetone. The specimens were taken to the Laboratory of Insect Biology, at the Universidade Federal de Pelotas, to sorting, counting, sexing and identification. Of the mosquitoes caught, specimens of Culex sp. Ochlerolatus scapularis and Mansonia titillans were present. Culex sp. had the largest number of individuals (39).

Trypanosoma cruzi, the causal agent of Chagas' Disease, is a widely spread protozoa in America. Blood transfusion is the secondly most important way of acquiring the infection. In blood banks, tests are performed to eliminate potentially infected blood. This study aimed to evaluate the positivity for T. cruzi in blood samples of donor's candidates in Southern Brazil. The study was based on a sampling containing all blood donors of Hemopel - a Pelotas City Blood Center, Rio Grande do Sul State, Brazil, from 2004 to 2005. Serological study was performed using ELISA Chagatest. Sampling containing values ± 20% cut off were evaluated using ELISA Chagatek, ELISA Alka/Adaltis, IHA Chagatest and IIF Imunocruzi. TESA-Blot was used as a confirmatory procedure in situations where blood samples showed conflicting results. From 4,482 samples collected in 2004 and 2005, the reactivity for anti-T. cruzi was 0.96% (43). Among those, 21 cases (0.47%) were confirmed as positive - most of them were female, with low school level and averaging 47.2% years old. Interestingly, the blood donors are not aware of being contaminated and this fact makes it difficult for controlling the disease. Chagas' Disease was one of the main reasons for discarding blood bags through serological control in Southern Brazil. Sampling reactivity showed variation among the different techniques used for anti-T. cruzi research. In order to obtaining more secure and conclusive results, more than one diagnostic technique must be used.

RESUMO O objetivo deste trabalho é relatar a ocorrência de acidentes em humanos causados por Epicauta excavata Klug, 1825 (Coleoptera, Meloidae), no sul do Rio Grande do Sul, Brasil. Este relato constitui o primeiro registro de acidente por Epicauta nesta região e por E. excavata, no Brasil.

ABSTRACT This article reports on the occurrence of accidents in humans caused by Epicauta excavata Klug, 1825 (Coleoptera, Meloidae) in southern Rio Grande do Sul, Brazil. This work is the first report of accidents caused by Epicauta in this region and by E. excavata in Brazil.