Dispersion ofInopus rubriceps1and Predation by Birds and Fish

Abstract

Males of Inopus rubriceps (Macquart) fly near crop level in emergence areas whereas females, once mated, gain altitude on their dispersal flight. Both sexes were caught in oil-bath traps up to 54 cm above ground level, but females only were trapped at or above 83 cm. Birds and fish are Implicated in predation. The most important fish predator of I. rubriceps In the Clarence River near Hielaman Island was the clupeid Potamalosa richmondia (Macleay). None of the predators observed to date bring about much populatIOn suppression in sugarcane fields that are already infested. In the Harwood Mill area, their value lies rather in slowing down the rate of dispersion by I. rubriceps.