CHINCH BUG CONTROL

What are Chinch Bugs and why are they killing my St. Augustinegrass lawn?

Chinch bugs are small insects (1/8th inch long) with straw-like mouthparts that feed on the fluids in grass plants. Immatures (nymphs) and adults feed in groups while hidden at the base of the grass. Infested turf eventually grows slower, yellows, then dies in small patches. The speed of turf death probably depends on chinch bug density and the turf’s overall health.

Why are Chinch Bugs hard to control?

• Other insects that live in lawns can be easily confused for chinch bugs, but may not hurt grass.
• Each year chinch bugs have 7-10 generations in southern Florida. All life stages (eggs, nymphs, adults) are present at the same time. Current insecticides only kill nymphs and adults, so eggs can still hatch and produce another generation. Chinch bugs usually complete their development from egg to adult in 5-6 weeks. One female can lay up to 300 eggs in her lifetime.
• Natural enemies (e.g., big-eyed bugs, spiders, a parasitic wasp, and others) are not abundant and efficient enough to keep chinch bug populations under control.
• Some insecticides bind tightly to organic matter (e.g., leaf blades, thatch) if they are not applied with enough water volume or are not irrigated soon after an application. The insecticides must get to where the insects are living and feeding to be effective.
• Most insecticides used against chinch bugs break down within 2 months or less, and need to be reapplied. Factors that affect the length of insecticide residual include pH, soil type, and amount of thatch.
• Some chinch bug populations have been repeatedly treated with the same kind of insecticides (e.g., Pyrethroids) for the last 5-10 years. A few chinch bugs may survive each treatment, reproduce, and pass on their ability to tolerate the insecticides. Since chinch bugs don’t move far, insecticide tolerance/resistance may be localized to areas that have been under long-term, intensive lawn care.

What can I, the consumer, do to help?

• Notify NativeGreen before chinch bugs are abundant and turf damage becomes severe.
• Turn on your irrigation after an application has been done.
• Make sure your irrigation system is functioning properly.
• Try to understand that lawn care is a service industry, and they are doing their best to ensure that you have a lawn that you can safely enjoy.

What is NativeGreen doing about insecticide-resistant chinch bugs?

• Where resistance is suspected, insecticides with different modes of action are rotated. Consistently effective products contain one of the active ingredients: bifenthrin, carbaryl, clothianidin, or trichlorfon.
• Higher label rates of these insecticides might be used to ensure that most of the “resistant” chinch bugs are killed. This may, however, increase the cost of chinch bug control.