ABSTRACT
Studies with insect growth regulators (IGR) and the red imported fire ant (RIFA), began in the early 1970s when E. W. Cupp, J. O'Neal, S. J. Troisi, and L. M. Riddiford, found that methoprene and hydroprene interfered with maturation of developing larvae, normal metamorphosis, and caused worker mortality. They concluded that for effective control the IGR must be more resistant to breakdown or it must be formulated in a way that prevented or retarded breakdown. Baits are prepared by dissolving the IGR in once-refined soybean oil and spraying the solution onto 8 to 30 mesh pregel defatted corn grits as they are tumbled in a mixer. The effectiveness of a chemical against a colony is determined by comparison of the pre- and post-treatment colony indices. The effects of IGRs on RIFAs in both laboratory and field have been dramatic and show that these chemicals can be effectively used in RIFA population management programs.
