Yes, chinch bugs are harmful. These insects suck the sugary sap right out of the grass blades in your lawn. After removing the moisture from the plant, they inject a toxin from their saliva into the blade. Your grass cannot recover from chinch feeding. 

They enjoy red fescue and Kentucky bluegrass which make up over 80% of the lawns in Canada. 

It's very tough to differentiate between chinch bug and drought damage. They can both look very similar, however, usually Chinch bug damage is less uniform and the damage is in specific areas that aren't connected. Whereas for drought damage, the damage is consistent and uniform throughout. The Canada government did a great article on how you can detect them, checkout their article here.

In short yes, but there are a couple conditions. After the first application, the lawn won't magically grow back and fill in where the damage occurred. However, it will reduce the chinch bug population up to 75% reducing further damage and breeding. We'd recommend getting a fall aeration and fertilizer package to help bring your lawn back. By next spring, the lawn should be somewhat recovered and with good seeding, fertilizer, watering and mowing the lawn should be in much better shape. It's a continual process to get your lawn back after the damage has been done but getting it sprayed for chinch bugs is a great first step.

Hire A Professional To Deal With The Problem

A certified professional has the proper product and safety equipment. Insecticides contain very strong chemicals so it's best you leave it to professionals.

Avoid going DIY because off the shelf products aren't specifically designed for chinch bugs, are diluted and less effective than commercial products.

Your grass will NOT grow back after it undergoes chinch bug damage. These pests will inject a toxin which entirely kills the blade of grass and it will not recover. 

Once your grass has died, you'll need to put down topsoil and seed, making sure you water consistently. You'll see new grass growth in a matter of weeks.

However, if the damage has gotten to far out of control you'll need to re sod. Re sodding can cost you up to $6000. You want to treat the damage before it gets to that point. 

Chinch bugs become active and star becoming a problem in June and persist greatly into July and August. As the temperatures start increasing and rain is less frequent chinch bugs arrive ad begin feeding.

We recommend using one of these two methods to tell if you have chinch bugs in your lawn or not. Perform one of these as soon as you suspect a problem, you don't want to wait to see the damage chinch bugs can do.

The Scrape And Inspect Method:

1. Get on all fours and with your fingertips scratch back the area of concern

2. Dethatch the area until you start ripping out some of the grass roots and take a look at the soil area

3. If you see 4mm long black black bugs with white spotted wings crawling around you have a problem

The Coffee Tin Method:

1. Cut the bottom off of a container of coffee and really push it down into the grass so that the edges go into the soil about 5cm in depth

2. Pour in the water so that the container fills up about 70% 

3. Hang out for 5-10 minutes and watch to see if chinch bugs start floating up to the surface of the water

4. Do this in all areas of concern, but also in areas that don't appear to be infected yet just to see if the problem has spread or if it can still be mitigated

Chinch bugs do not go away in winter. They freeze and hibernate during the winter months and thaw and come back to life when the weather warms up. 

Chinch bugs are drawn to stressed and heavily thatched lawns. The best way to avoid a chinch bug infestation is by keeping your lawn well irrigated, mowing consistently, and aerating annually. Additionally, these bugs love grasses with a high nitrogen content. Avoid liquid fertilizer, and instead use slow release granular fertilizer. 

Adult chinch bugs live an average of 50 days. This gives them ample amounts of time to suck the moisture out of every blade of grass in your lawn. Especially because of how quickly these pests reproduce.