Chinch bugs

How do I know if I have a problem?

There are several ways to confirm an infestation:

• Chinch bugs give off an offensive odour when crushed. If your lawn has a noticeable odour when walked on, you could have a large infestation.
• Spread the grass and check the soil surface for red nymphs or black adult chinch bugs. These bugs avoid the light and may hide in soil crevices.
• Use this method in cases where the bugs are not readily visible:
  
  1. Cut the bottom out of a coffee can or large juice can and force it 5 cm (two inches) into the turf surface.
  2. Fill the can with soapy water, adding more water if the level recedes.
  3. Wait five to 10 minutes. If you have chinch bugs, they will float to the top of the can.
  4. Try this in several areas of the lawn, including lawn edges. If there are five to 10 chinch bugs per can, the infestation is serious enough to damage turf.

Healthy turf should be able to tolerate a level of two or three bugs per can. However, turf that is in poor condition or stressed by hot, dry weather may not tolerate even a low-level infestation.

How can I get rid of chinch bugs?

Chinch bugs like poorly tended lawns with compacted soils, accumulations of thatch, and a lack of moisture or an excess of nitrogen. Maintaining your lawn properly will discourage infestations and improve tolerance to damage. Some helpful practices include the following:

• If replanting grass, choose an insect-resistant, endophytic variety of tall fescue or rye grass (endophytes are naturally occurring fungi that kill lawn pests, including chinch bugs).
• Aerate the lawn in spring to reduce soil compaction.
• Remove thick layers of thatch (organic debris on the surface of the soil) in the fall. Keep in mind that some thatch may be needed to prevent winterkill in cold regions.
• Do not over-fertilize, since this will encourage greater insect activity.
• Use water-insoluble or slow-release nitrogen fertilizers. Using 1 kg of nitrogen per 100 m2 (approximately 2 lb per 1000 ft2) should be enough for most lawns.
• Water the lawn thoroughly (but not more than once a week) during the summer.
• Keep soil moist to a depth of 6 to 8 cm (2.5 to 3.5 inches).
• Do not cut the grass too short. A length of 6 to 7.5 cm (2.5 to 3 inches) will help avoid stressing the grass.
• Add agricultural limestone when the soil pH is below 6.5.

Predators

Natural predators and parasites serve to keep chinch bug numbers under control:

• The big-eyed bug likes to dine on its relative, the chinch bug. It looks similar to the chinch bug, but has a wider body, larger head and large predominant eyes.
• The tiny wasp will live off of chinch bug eggs under favourable conditions, preventing them from hatching.

These predators occur naturally, or can be bought from a commercial insectary.

Chemical products

There are some pesticides available for consumer use that can treat an infestation of chinch bugs. Before buying a pesticide, check the label to make sure that it is registered for this use.

Treat the entire lawn when damage is first noticed in June. A second application may be needed in August to kill the second generation. Treating after mid-August is not particularly effective; it is best to wait until the following June.