The effects of hue and intensity on visual attraction of adult Tabanus nigrovittatus (Diptera: Tabanidae)

The visual attraction of adults of Tabanus nigrovittatus to various hues and intensities was studied in a Spartina salt marsh in Massachusetts, using 2-dimensional sticky panels. Collections consisted mainly (98%) of host-seeking parous females; the remainder were nulliparous females and males. Parous females were strongly attracted to blue and moderately attracted to black and red, all of which have reflectance in the range 400-800 nm. Yellow, yellow-green and white were consistently unattractive. Attraction to white panels, with and without ultraviolet (UV) reflection, and aluminium foil varied inversely with the amount of UV reflected. Increasing or decreasing intensity of hues increased the attraction of flies; this was the result of increased contrast with the background.