Q. I have chinch bugs in a major way in our lawn. How do I get rid of them without using pesticides?
A. First, let’s make sure the damage you’re seeing is caused by chinch bugs! Adults have black bodies with white wings and are about four millimetres long. Nymphs are bright red with a white band across their back. As the nymphs mature, their colour changes from red to orange to brown and then black. Both give off a non-pleasant odour when they are stepped on. If you get a not-so-pleasant smell when walking on your lawn this could be an indication that you have an infestation!
Chinch bugs damage lawns by feeding on the stem and crown of grass, puncturing the grass with their piercing mouth parts. They suck the sap out of the plant which causes brown or yellow areas of dead grass. These areas get larger in size as the chinch bugs continue to feed on surrounding grass.
During the summer it is normal for grass to dry out which can make it difficult to tell if the damage is because of drought or chinch bugs. One key way to distinguish between the two is that chinch bugs cause damage to your grass in patches. In comparison, a drought typically causes damage across your lawn.
To determine if your lawn is suffering from an infestation of chinch bugs there are a couple of things you can do:
- Use a can opener to cut both ends off a coffee can and push it into the ground (using gloves so you don’t cut yourself!) about five centimetres, near a yellow or brown patch. Fill the can with soapy water and wait 10 minutes. If you have chinch bugs, they will float to the top of the can. Repeat this in a few areas of your lawn. If there are five to 10 chinch bugs in each can, this is an indication that your lawn could be suffering from chinch bugs.
- Alternatively, you can seperate the blades of grass and look at the top of the soil for red nymphs or dark adults. Focus these efforts on green grass areas that border a dead patch. A magnifying glass may help! Be sure to check several areas of your lawn. If you see more than 15 of these critters within two minutes in one area, they may be the cause of your lawn damage.
If you have determined that chinch bugs are the culprits causing the damage to your lawn, there are some practices that can help that do not involve pesticides! They like it when there is an accumulation of thatch, compact soils, a lack of moisture and lots of nitrogen. To help control the chinch bugs in your lawn:
- Reduce soil compaction by aerating your lawn in the spring. This may make your lawn less inviting!
- Remove excess thatch from your lawn. What is thatch? It is a buildup of dead and old grass material. A rake is great tool to reduce thatch!
- Maintain your lawn at a proper height, cutting no more than one-third of the leaf blade, to avoid stressing the grass. It is suggested that grass be kept at a height between four to 7.5 cm.
- Chinch bugs prefer dry conditions. If you water your lawn, water deeply, about two to three cm once a week, preferably in the mornings to avoid evaporation. Be sure to check with your municipality to see if there are any bylaws that govern lawn watering.
- Add two tablespoons of Castile liquid soap to a spray bottle filled with water. In the morning, drench the yellow patches of grass and surrounding 1.5 m. Place flannel sheets over these areas and wait about 15 minutes. The chinch bugs will attach themselves to the sheet. After 15 minutes, take the sheet off and dispose of any chinch bugs. Water these areas. The next morning part the grass and look for chinch bugs. If you see some, use a strong vacuum such as a Shop Vac to vacuum them up. This will help get rid of any remaining eggs, nymphs and adults. This may need to be repeated over the next few days.
- Insect eating birds can be a great ally to you when trying to control a chinch bug infestation. Putting some birdseed on the damaged areas of your lawn may attract birds that will not only eat the birdseed but the chinch bugs too!
