EUROPEAN CHAFER BEETLE VANCOUVER

The European chafer, Rhizotrogus majalis, is an introduced insect that has become a serious pest of turf in Eastern North America. It was first discovered in New Westminster in late 2001 and has since spread beyond New Westminster’s boundaries.

Adult European chafers are tan or brown beetles resembling June beetles but measure only about 1.5cm in length. The grubs, measuring 2 to 2.5cm, are soft, white and C-shaped with tan-coloured heads and six prominent legs.

Chafers complete their life cycle in one year which can lead to rapid population increases. In British Columbia, the adult beetles emerge from the soil in early to late June and mate in swarms at dusk. In June and July, females lay up to 20 to 30 eggs in the soil. The eggs hatch in about 2 weeks and the small grubs begin to feed on the roots of turf. Damage is seen in the fall to early spring when the grubs are full-grown. Feeding continues throughout the winter except during prolonged periods of freezing temperatures. The grubs feed until the pupate in May.

  WHAT DO DO?  MONTH BY MONTH

JANUARY-MARCH

Large grubs found in soil feeding on turf roots. Raccoons, skunks and birds may be seen tearing the turf apart and turning it over to find the grubs in the soil.

NO CONTROL OF CHAFER AT THIS TIME

Assess damage from chafer larvae and chafer predators to lawn:

• Turn over 1 square foot sections of lawn (5 sections per lawn).

• Dig through soil beneath grass, counting number of chafer larvae found.

• If more than 5-10 chafer found per square foot section, chafer control may be necessary. Consider nematode application in July

 

APRIL-JUNE

Grubs enter a resting stage (pupa) in May prior to emerging as adults in June. Adults may be seen flying in swarms at dusk in June.

Repairing Damaged Lawns

• Lightly rake over damaged turf areas.

• Apply a light (¼ to ½ inch depth) topdressing of compost sand mix or lawn topdressing soil mix.

• Reseed damaged lawn areas.

• Roll the newly seeded area lightly with a roller for good seed/soil contact.

• Apply a starter fertilizer.

Maintaining Established Lawns

• Aerate compacted soil

• Apply an organic based lawn fertilizer

• Mow once per week, maintaining the grass at a height of 5-6cm. Leave the grass clippings on the lawn if possible.

Water newly planted lawns frequently (daily if necessary) to keep the soil surface moist until 50% of the seeds have germinated. Water lawns twice weekly, giving the lawn about 2.5 centimetres of water a week. Lawns should be watered on and off at 30 minute intervals to avoid run-off and allow the water to soak in. Follow local watering restrictions.

 

JULY

Eggs laid in the soil hatch in July and small grubs begin feeding on turf roots.

Mow once per week, maintaining the grass at a height of 5-6cm. Leave the grass clippings on the lawn if possible.

Water lawns twice weekly, giving the lawn about 2.5 centimetres of water a week. Lawns should be watered on and off at 30 minute intervals to avoid run-off and allow the water to soak in. Follow local watering restrictions.

TIME TO CONTROL CHAFER

Apply nematodes, during the third week of July. Water the lawn for 3 hours prior to nematode application and for 3 hours following nematode application. Nematodes should be applied in the evening or on a cloudy day.

 

AUGUST-SEPTEMBER

Small grubs found in soil feeding on turf roots. Wilted or dead patches in turf may be visible if grub feeding becomes excessive.

Mow once per week, maintaining the grass at a height of 5-6cm. Leave the grass clippings on the lawn if possible.

Water lawns twice weekly, giving the lawn about 2.5 centimetres of water a week. Lawns should be watered on and off at 30 minute intervals to avoid run-off and allow the water to soak in. Follow local watering restrictions.

 

OCTOBER-DECEMBER

Large grubs found in soil feeding on turf roots. Raccoons, skunks and birds may be seen tearing the turf apart and turning it over to find the grubs in the soil.

NO CONTROL OF CHAFER AT THIS TIME

Minimize skunk and crow damage by replacing and patting down clumps of grass immediately after they have been pulled up.

 

*Taken from City of Vancouver website lawn care