Seasonality and landscape use by Tabanidae species (Diptera) in the Central Amazon, Brazil

Abstract

Adults of Tabanidae may become serious pests wherever they occur due to their attack to humans and others animals. Tabanids were captured near ground, water surface and at 25 m high on primary forests and forest gaps of anthropogenic origin, to understand their abundance, seasonality, diversity and similarity on such environments. Collections were carried out in the Base II of the War Instruction Center in the Jungle (CIGS) located at 54 km from Manaus municipality, Amazonas state. Two Malaise flight interception traps and four attraction traps (two suspended at 25 m high and two above the water surface of igarapé) were installed in forest gap and primary forest, areas for 10 consecutive days, during 15 months. A total of 2,643 specimens of 66 species were captured. Diachlorini (35 species /11 genera) was the most abundant tribe, followed by Tabanini (19 species /three genera), Chrysopsini (seven species /one genus) and Scionini (five species /two genera). Seventeen species were captured only in the primary forest, 11 in the anthropic clearing, and 38 species were common to both environments. The most abundant species were Phorcotabanus cinereus (Wiedemann), Tabanus occidentalis L, Chrysops laetus Fabricius and Tabanus angustifrons Macquart. The greatest richness was found in drier months (September/October) in both areas. The forest gap showed higher abundance of specimens (1,827) than the primary forest (816). Traps suspended above the water surface were the most efficient (1,723 specimens) probably due to the dispersion of horseflies over small streams.