Seasonality and diurnal activity of Tabanidae (Diptera: Insecta) of canopy in the adolpho ducke forested reserve, Manaus, Amazonas State, Brazil

Abstract

The seasonality and diurnal flight activity of tabanids from canopy was studied at Ducke Reserve, in the county of Manaus, Amazonas State, Brazil, using a suspended trap installed at 20 m above the soil, connected to the carbon dioxide gas cylinder. During one day, twice monthly collects of Tabanidae were taken from April 2000 to June 2001. The material was collected from the trap in intervals of 2h and placed in plastic tubes. A total of 955 individuals, corresponding to thirty species were collected. Philipotabanus stigmaticalis (Kröber) (37.9%) was caught all over the year and showed higher flight activity between 12:00 p.m. and 4:00 p.m. Acanthocera marginalis Walker (16.3%) was more abundant in the less rainy months (July to November) with a higher activity period between 10:00 a.m. and 12:00 p.m. Acanthocera gorayebi Henriques & Rafael (9.0%) was more abundant in July with more activity between 10:00 a.m. and 12:00 p.m. Dichelacera damicornis (Fabricius) (10.9%) was more abundant in the months of heavier rainfall (January, February and April) and showed higher diurnal activity between 10:00 a.m. and 2:00 p.m. Diachlorus podagricus (Fabricius) (6.6%) was caught throughout the year except in February and showed higher activity between 10:00 a.m. and 14:00 p.m. The climatic factors when correlated to the tabanids richness just showed significant correlation with precipitation, while the specimens abundance was correlated to humidity and precipitation.