One element of lawn care in the Fraser Valley is dealing with specific pests in your lawn. Such as the European Chafer Beetle and the European Cranefly or Leatherjacket.
See also: Controlling pests with Nematodes
European Chafer Beetle
A European Chafer completes its life cycle in one year
April to Late June
The adult Chafer beetles emerge from the soil and fly to nearby trees to mate and feed. The females once they have mated, deposit up to 50 eggs in the soil. The chafer beetle does very little damage to the lawn during this period.
July thru September
The eggs begin to hatch in July and the grubs will begin to feed on the lawn. The grubs begin to tunnel under the lawn at this time and the turf may feel spongy when walked upon. You will see damage to the turf during this time which will show up as dead or dying patches of grass. You will want to monitor your lawn during the summer months as dead grass can also be caused by European Crane fly (Leatherjacket) larvae as well.
October thru March
Chafer beetle grubs will continue to feed and grow through the fall and winter months. During mild weather the grubs will stay within 5cm of the surface of the soil but can burrow deeper during colder weather. It is at this time that most of the damage to lawns may appear as raccoons, skunks and crows may tear up the turf as they feed on the grubs. The grubs will continue feeding until they pupate to become adult beetles in May.
Monitoring for Chafer beetles:
Cut three sides of a 1’ x1’ (30 cm x 30) cm square of grass to a depth of about 2” (5cm).
Peel and fold back the patch of turf and count the grubs in the soil by digging around. You may have to use a trowel to help loosen the turf to peel it back.
You can cut five more squares of sod/turf in different areas of your lawn, count the grubs in each square.
Finding 5 or more grubs per square usually means that control is necessary.
Chafer Beetle Control:
- Applying Bacillus thuringiensis subsp. galleriae (Grub B Gon) in late July.
- 1 bag per 1000 sq/ft
- Apply from April to July
- Once the Beetles are in their egg hatch stage
- Apply approximately 1” of water after application to allow product into the root zone
- Your lawn should be thoroughly watered to a depth of 4” before applying the nematodes. A healthy lawn is essential for achieving control when using Bacillus thuringiensis subsp. galleriae.
- After applying Bacillus thuringiensis subsp. galleriae you must keep the lawn thoroughly watered for two weeks to achieve effective control.
Life Cycle of European Cranefly / Leatherjacket
Resembles a huge mosquito (size 1.5cm to 2.5cm) with greyish brown body.
Light grey, greenish brown cylindrical grub
with tapered ends, 3-4 cm at maturity.
Brown, spiny and 3.3cm in length.
March thru June
The larvae, which have been dormant over winter, feed and grow during this time. This is the stage at which the larvae do the most damage to the lawn. Nematodes should be applied at double the rate during this period to kill the larvae.
The Larvae stop feeding and move down into
the soil (3-5cm). Damage to the lawn will diminish during this period.
Pupate in mid to late August at which time the adults emerge.
September thru October
Adults emerge lay 200-300 eggs, and live 4 -7 days. The winged adults do not feed during this period and only mate and reproduce. The eggs, which are laid, need immediate moisture to survive and hatch 11-15 days later. Once hatched the larva feed throughout fall and warm periods in winter in upper 3cm of soil. This is the easiest time to ill the larvae.
In early spring (March thru May) it is possible to have good success applying the nematodes on the feeding larva, however the rate of application must be doubled. Nematodes are usually only applied in situations where the damage is severe in spring.
Late summer and early fall is the preferred application time for Nematodes as the larvae are smaller and more easily killed.
Coverage Area: Green Earth Nematodes
Fall: 3000 sq/ft
Spring: 1500 sq/ft
For both applications it is important to make sure the lawn is well watered, fertilized and healthy before applying the nematodes.
You can rent portable liquid drop spreaders for effective application of the nematodes.
You can apply for a water exemption permit from most municipalities during this period if required.