Color and uV reflectance of canopy traps for collecting horse flies (Diptera: Tabanidae) in Louisiana

The effect of colour and ultraviolet light (UV) reflectance on the catch of horse flies in carbon dioxide baited canopy traps was studied in south-central Louisiana, USA. Black traps collected significantly more Tabanus americanus, T. fuscicostatus, T. limbatinevris, T. lineola group and T. proximus than did blue or red traps. T. wilsoni was captured in greater numbers in black traps than in red traps, whereas there was no difference between catch of this species in black and blue traps or in blue and red traps. There was no difference in the number of flies captured by the different coloured traps for Chlorotabanus crepuscularis, Chrysops spp., Leucotabanus annulatus, T. equalis and T. pallidescens. More flies on the T. lineola group were captured in traps with increased or decreased UV reflectance than in control traps. Traps with decreased UV reflectance captured more T. proximus than did control traps, but there were no differences in number of T. proximus captured in control traps and traps with increased UV reflectance, nor between traps with increased or decreased UV reflectance. Black traps are most effective for collecting Tabanidae in southern Louisiana during midsummer. There appears to be little effect of UV reflectance on collection of most species of Tabanidae.