Chafer Beetles: How We Got Here, What’s Happening, and How to Get Ahead

If your turf has been shredded by crows or raccoons this fall, you’re not alone. The European chafer beetle has been chewing through lawns across Metro Vancouver/Fraser Valley for years, and wildlife tearing up turf to eat the grubs often causes even more visible damage.

This post breaks down the story so far, what’s happening in your lawn right now, and the practical, science-backed steps to protect and restore your turf over the next few seasons.

How we got here

The European chafer beetle (Rhizotrogus majalis) was first detected in British Columbia in 2001, in New Westminster boulevards and lawns. From there it spread throughout Metro Vancouver, helped along by a one-year life cycle, evening flights, and movement in infested soil, sod, and nursery stock. Metro Vancouver+2Government of British Columbia+2

While origin stories vary, the common thread is movement of plant material and soil: chafers (at egg or grub stages) can hitchhike in tree balls, sod, and contractor trailers, exactly the pathways that let them hop neighbourhoods. Metro Vancouver

What’s happening now (and why wildlife is ripping up turf)

Chafer grubs feed on grass roots from late summer into fall, overwinter in the soil, and resume feeding in spring. Adults emerge in late May – June, swarm at dusk, and lay eggs in July; those eggs hatch within ~2 weeks. The youngest grubs (late July–August) are the most vulnerable to biological controls like nematodes. City of Richmond

Raccoons, skunks, and crows are “helping” themselves to grubs, which is why many homeowners wake up to flipped sod or rolled sections of lawn, the wildlife damage can exceed the feeding damage. Metro Vancouver

Where we go from here: a realistic, multi-year plan

There’s no silver bullet. A successful program combines good turf care, timed treatments, and expectation management over 2–3 seasons.

1) Make your lawn a harder target

Healthy turf tolerates pressure better and is less attractive to pests.

  • Irrigation: Deep, infrequent watering to build roots; follow municipal rules.
  • Nutrition: Balanced fertilization based on a soil test.
  • Cultural practices: Aeration, topdressing with quality compost/soil, and overseeding (tall fescue blends perform well for durability; micro-clover can improve resiliency and reduce fertilizer needs).
  • Mowing: Keep it taller to shade the soil and strengthen roots.

These practices won’t “cure” an infestation, but they reduce severity and speed recovery. Municipal and provincial guidance consistently emphasize lawn health as prevention. Maple Ridge, BC

2) Choose the right control(s) for the right window

Biological: Beneficial nematodes (Heterorhabditis bacteriophora)

  • Best timing: Late July to early August, when grubs are newly hatched and near the surface.
  • Critical to success: Quality nematodes are key to your success. Nematodes are living creatures and must be used quickly after purchase. Their viability is entirely dependent on their freshness.  Pre-water deeply, apply in low light, and keep the soil moist for ~2 weeks after so nematodes can move and find hosts. Poor moisture or mistimed applications are the #1 reason for failure. Government of British Columbia+2Coquitlam+2

Biological: Bacillus thuringiensis subspecies galleriae (Btg)

  • Available to homeowners in Canada (e.g., products marketed for “grubs”).
  • Works by ingestion; multiple seasonal applications (spring/summer/fall) are often recommended on labels; always follow label directions. Effectiveness can vary with timing and grub stage. Scotts+1

Professional insecticide: Chlorantraniliprole (Acelepryn/Acelepryn G)

  • Preventive window: Typically spring to early summer so the active is in the soil before peak egg hatch; used widely in turf for white grubs.
  • Traits: Long residual in soil and low mammalian toxicity profile per regulatory summaries; must be applied according to the label and local bylaws, by licensed professionals. Labels SDS+1

Important: Cosmetic pesticide bylaws and municipal rules vary. Always check your city’s allowances and watering exemptions (many municipalities offer temporary watering permits to support nematode applications). Coquitlam

3) Restore after control

Even with good control, wildlife damage may leave thin or bare patches. Plan for:

  • Topdressing + overseeding immediately after treatment windows.
  • Repeat overseeding in fall and again in spring to thicken turf.
  • Soil improvements where new construction left poor topsoil—thin, compacted subsoil is especially vulnerable to chafer damage.
  • Preventative treatments Follow up treatment is generally necessary to prevent re-infestation.

4) Consider alternatives in tough sites

Where grass struggles (shade, poor soil, high traffic), alternative plantings can reduce maintenance and pest pressure:

  • Tall fescue-dominant mixes for durability
  • Micro-clover/turf-clover blends for resilience
  • Native and pollinator meadow mixes where a lawn isn’t required

These alternatives may have a different appearance than standard lawn blends

(Choose mixes suited to local conditions and bylaws.)

The chafer calendar (Lower Mainland)

  • Late May–June: Adults emerge and swarm at dusk.
  • July: Eggs laid; late July–early August = prime nematode window.
  • Aug–Oct: Grubs feed; keep turf healthy and irrigated as permitted. Initial or secondary biological and insecticidal treatments(professionals only) can be applied
  • Winter: Grubs overwinter in soil.
  • Spring (Apr–May): Grubs resume feeding; preventive professional treatments may be scheduled so active ingredients are in place before eggs hatch. Biological treatments can be used to attack existing grubs
  • Year-round: Aerate/topdress/overseed at seasonally appropriate times. City of Richmond+2Government of British Columbia+2

Common myths (and why they backfire)

“I’ll just flood the lawn” or “Boil weeds/soil with hot water.”

Hot water or excessive flooding damages turf and soil biology without solving the grub problem.

“If wildlife tore it up, I must treat right now, any product will do.”

Many products only work on specific life stages. Off-window applications waste money and won’t stop current wildlife activity. Time controls to the lifecycle. Government of British Columbia

Expect a multi-year cycle and plan accordingly

Populations often get worse before they get better, especially where soil is poor or turf is thin. A realistic plan is 2–3 seasons of combined cultural practices, on-time treatments, and regular overseeding. When it’s done well, you’ll see fewer wildlife disturbances, stronger turf, and less re-infestation pressure over time. Government of British Columbia

Quick starter plan

  1. Spring (Apr–May): Soil test; fertilize appropriately; aerate and topdress; overseed. Discuss preventive professional options (chlorantraniliprole) subject to local bylaws. Labels SDS.
    Biological product can be applied
  2. Early Summer: Maintain irrigation and mowing height; book nematodes.
  3. Late July–Early Aug: Apply nematodes with heavy pre- and post-watering per instructions. Coquitlam+1
  4. Fall: Repair patches; topdress + overseed again; keep turf healthy going into winter. Follow up treatments are recommended from Labour day until late October. The soil must moist.
  5. Next Spring: Repeat overseeding; reassess. Consider Btg products as labelled adjuncts for homeowners. Scotts

Helpful local resources

Product/regulatory info: Acelepryn label & B.C. Q&A; homeowner Btg products. Labels SDS+2Government of British Columbia+2

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