To characterize the local insect fauna, samples were obtained weekly from September/1999 to August/2000 through Malaise traps installed at the edge and inside the forest. A temporal analysis of Syrphidae species collected approximately 17 years ago at the same local, inside the forest, was made. Also, the abundance and species richness between the areas were analyzed. The syrphids were more abundant at the edge of the forest than in the interior, and the number of species as well. Comparing the current data with the data obtained in 1986/1987, a decrease in the local abundance and species richness was registered. The most abundant species at the edge was Allograpta neotropica Curran, 1936, and inside the forest (1999/2000) was Ocyptamus sativus (Curran, 1941). The specimens of Toxomerus Macquart, 1855 were the most abundant in the trap located at the forest edge, and those of Ocyptamus Macquart, 1834 in the forest interior. Ninety-five species were identified in 22 genera. Ocyptamus was the genus with the highest species richness (23). In the sequence were Copestylum Macquart, 1846 (15), Toxomerus (15) and Microdon Meigen, 1803 (10). Seven species were common among the three samples: Allograpta neotropica, Copestylum selectum (Curran, 1939); Leucopodella gracilis (Williston, 1891); Mixogaster polistes Hull, 1954; Ocyptamus funebris Macquart, 1834; Toxomerus procrastinatus Metz, 2001 and Toxomerus tibicen (Wiedemann, 1830). Three new species of Microdon, one of Toxomerus, one of Aristosyrphus Curran, 1941, and one of Myolepta Newman, 1838 were identified.
Diptera; Malaise trap; Neotropical; species richness; Syrphidae
