Christmas tree (Common pests)-White grub

Includes Polyphylla decemlineata, Plecoma spp., Aphodius spp.

Pest description and crop damage Small to large C-shaped, white scarab beetle larva with six legs and a brown head. Grubs feed on roots, often killing young trees. Many follow the soil moisture and may appear absent in summer.

Management-biological control

Some growers have observed partial control from parasitic nematodes, but results are poorly replicated.

Management-chemical control

To date, chemical control on established large grub populations has not been effective.

  • bifenthrin (Brigade, OnyxPro, Sniper and others)-Restricted use pesticide. (Group 3)
  • carbaryl (Sevin and others)-(Group 1)
  • imidacloprid (Admire Pro, Nuprid 2F)-(Group 4)
  • thiamethoxam (Flagship 25 WG)-(Group 4)