Responses of horse flies (Diptera: Tabanidae) to Jersey bullocks and canopy traps baited with ammonia, octenol, and carbon dioxide.

The attraction of females of six species of tabanids to stanchioned Jersey bullocks, unbaited canopy traps, and canopy traps baited with either octenol (1-octen-3-ol), ammonia (NH4OH), a combination of ammonia and octenol, or 5 kg of dry ice (CO2) was studied. A randomized Latin square design (treatments x sites x days) was used. Species diversity and number of flies captured in canopy traps unbaited or baited with octenol, ammonia, or the combination of octenol and ammonia did not differ significantly. Females of Tabanus americanus Forster, T. fuscicostatus Hine, and T. lineola F. were captured more frequently in CO2-baited canopy traps than on Jersey bullocks, but the reverse was observed for females of Leucotabanus annulatus (Say). The number of females of T. pallidescens Philip and T. wilsoni Pechuman collected from CO2-baited canopy traps and bullocks did not differ significantly.