My Lawn is Damaged - Is It Hairy Chinch Bug?

The hairy chinch bug is native to North America. It originally fed on prairie grasses, but now finds home lawns just as appetizing. Chinch bug damage appears suddenly in mid-August as sunken brown patches of dead grass on lawns, often with weeds growing in them. Damage will probably be noticed first near hedges, trees or garden beds. The dead grass is firmly attached to the ground, as the roots are not damaged (unlike white grub damage). To verify that hairy chinch bug is responsible for the brown patches, remove the top and bottom of a large can (a coffee can is ideal) and twist it through the turf and into the soil in an area adjacent to the damaged grass. Fill the can with water and scrape the turf inside with your fingers. If hairy chinch bugs are present, they will float to the surface of the water after a few minutes. More than 20 - 25 bugs per sample indicate that you have a problem.

Chinch Bugs - Life History

Hairy Chinch bugs are tiny (approximately 5 mm) black and white insects, with six reddish legs. Their wings are white, with a dark spot on the outer margin and are held flat over their back. The immature stages look similar to the adult; however are a reddish brown colour with a white band across the abdomen, and black wings. They become darker as they mature. Both adults and nymphs have sucking mouthparts, and kill or damage grass by removing sap, and blocking the transport of water and food in leaf blades. Chinch bugs spend the winter as adults in protected places (e.g. in the thatch layer on the edges of flower beds, near hedges etc.). When temperatures warm up in the spring, these adults begin feeding and disperse across the lawn. Eggs are inserted into grass stems, or are deposited in thatch in May and June. Tiny nymphs hatch beginning in late May and begin sucking plant juices. They develop into adults by mid to late July. By this time Hairy Chinch Bug may have caused considerable damage.

How Do I Manage Chinch Bug Without Resorting to Chemical Pesticides?

• Hairy Chinch Bugs thrive in hot dry conditions. Water droplets may seriously damage young nymphs. Water lawns regularly beginning in late May to reduce the pest population.
• Chinch Bug does not like to feed on grasses infected with the fungus Acremonium. Plant endophyte-enhanced varieties of grass.
• A thick thatch layer provides many sheltering sites for chinch bug, and improves their winter survival; reduce excess thatch through proper lawn care practices.
• Chinch bugs prefer feeding on soft young grass. This type of growth is stimulated by applications of high nitrogen fertilizers. When you suspect you have a problem with this pest, modify your fertilizer application schedule.
• This is a native pest. There are many predators, parasites and diseases that reduce pest numbers significantly. Encourage these beneficial organisms by avoiding use of chemical pesticides on your lawn.

[ top ]