Posted By: Laurelle Olfdord-Down in Grasses
European Chafer Beetle or Rizotrogus majalis if you prefer the scientific name, is an introduced species that wreaks havoc on lawns. The grub itself likes to eat the roots of grasses but what often causes the most alarm in folks is the fact that Crows and Raccoons will tear apart what remains of your lawn in order to feast on this delicacy. Don’t panic. There is hope.
What is a European Chafer Beetle
European Chafer Beetle is a coppery tan coloured little beetle just a little over 1 cm long. The adult grubs are twice as long, white with a brown head and 6 legs. They are curved into a “C” shape. They would make an excellent monster in a scary movie actually if they were a lot bigger. The grubs feed in fall and spring. The adult beetles mate in the evenings in May and the females lay 40-50 eggs each which hatch in July. An excellent way to determine if you have an infestation before the crows, raccoons and moles clue you in is to peel back a square foot of sod and examine the soil underneath. If you count 5-10 grubs in one square foot of lawn area, you have a problem. The grubs preferred food is grasses, if there is not enough available they will move to other fibrous rooted plants.
Healthy lawns are better able to withstand some damage from small amounts of grubs. Irrigate deeply 2 to 3 times a week. Raise your mowing height. The female beetles prefer shorter, dryer lawns to lay their eggs in.
Photo Attribution: City of Burnaby
If the crows, raccoons and moles have begun the control methods (aka ripping apart your lawn), let them finish feeding before you begin alternative methods of control. They are messy but effective and will knock down a huge percent of the population. Your next step is to apply Nematodes in July.
Specifically, Heterorhabditis bacteriophora. Nematodes are a naturally occurring organism. The Hererorhabditis bacteriophora is a nematode which moves through the soil. They are not harmful to humans, pets or other animals including bees and earthworms. They specifically target grubs. They infect grubs 48 hours after application and will kill them 2 weeks after infecting them. They must be applied to a wet lawn on a cloudy evening. Application on dry lawn or in full sun conditions will kill them. The water will keep the grubs toward the surface of the soil and will enable the nematodes to move more freely. You must keep your lawn moist for about a week after application. You may need to obtain a watering permit from your municipality.
To Order Nematodes:
- Call us at 604.882.1201 to order/reserve Nematodes
- or use our online Plant/Product Request Form (under the Contact Us menu item)
There are also chemical methods to control the grubs. Chemical control will affect all soil organisms including earthworms and native bees and will also affect the animals that consume them. Check with your municipality BEFORE using a chemical control as many municipalities have banned the use of pesticides.
If your municipality allows chemical control of grubs and you are going to ignore the written equivalent of my deeply frowning face, you can apply pesticides such as Grub Out to your lawn according to directions, in the evening when there are no pollinators present. There are more than 400 species of native bees in BC and 70 percent of them live in the soil.
Please be careful of our pollinators and yourself if applying pesticides.
Once you have decreased the grub population to an acceptable amount, consider decreasing the lawn area with trees, shrubs or even an alternative ground cover such as micro clover or an eco-mix seed that contains some grass, low yarrow and clover. Our horticulturalists and designers are here to help. It may not be possible to maintain a golf green lawn, but it will be possible to come up with a solution that is good looking, healthy and one we can all live with.
More European Chafer Information Links