Color and shape as mediators of host-seeking responses of simuliids and tabanids (Diptera) in the Tantramar marshes, New Brunswick, Canada

Host-seeking responses of tabanids and simuliids to visual stimuli of colour and shape were investigated in the Tintamirre National Wildlife Area of New Brunswick, Canada, using 2-dimensional sticky silhouettes. Among the simuliids, Cnephia mutata (Mall.) oriented towards black, Prosimulium mixtum Syme & Davies to red and the complex of Simulium venustum Say and S. verecundum Stone & Jamnback to blue. Among tabanids, both Chrysops and Hybomitra spp. were attracted to blue or red silhouettes but never to yellow, black or white, and consistently chose the attractive colour portions of silhouettes striped with attractive and unattractive colours. Tabanids showed little preference between moving or stationary silhouettes. The shape of the silhouettes (square, triangle or disc) was of little importance either to simuliids or to tabanids.