• Introduction
• The Problem
• Developing a Management Plan
• Bait Basics

• Formulations
• Application Timing
• Broadcast Application Methods
• Speed and Duration of Control
• Cost-Saving Considerations

• Individual Mound Treatments
• More Information
• Disclaimer
• Contributors
• Print this Lesson

After broadcast application, the mode of action of the ingredient in these bait products determines the speed at which 80 to 90 percent maximum control is achieved. Baits that kill worker ants within a few days to a few weeks (including indoxacarb, fipronil, hydramethylnon, and spinosad) produce maximum results within several weeks after treatment. From that point, reinvasion of treated areas begins and may require additional treatments to maintain control. When used as individual mound treatments, results are even faster and often eliminate treated colonies in several days even where colonies are in inaccessible locations such as sidewalks and driveway cracks, bases of tree trunks, compost beds, and utility housings.

Insect growth regulator or IGR products (fenoxycarb, methoprene, pyriproxyfen) are synthetic chemicals that mimic an insect hormone. These ingredients do not generally kill worker ants, which must die of natural causes before a colony is eliminated. Rather, they affect queen ants and developing brood and prevent worker ants from developing for about a year following treatment. Effects vary by season. A spring or summer treatment achieves maximum control in several months while a late summer or fall application may require 6 months. These products are ideal for maintaining control, once achieved. Suppression from an IGR may last for a year or more. Abamectin containing products (Ascend, Clinch, Varsity) provide an IGR-like response when broadcast even though this ingredient affects the nervous system. When used as a mound treatment, results occur more quickly.