White grubs

White grubs

We often get questions regarding grubs in people's gardens. Your grubs are most likely the larvae of golden brown beetles or green fruit beetles. The golden brown beetle larvae, known as a masked chafer, is often seen in and can cause damage to lawns. The green fruit beetle larvae is found in vegetable gardens and compost piles and feeds on decomposing organic matter. There's also a third possibility, a hoplia beetle larvae. It's less common in Santa Clara County, and the grub is smaller.

Hand picking larvae is the cheapest and most effective method for combating these insects. But unless there are many, they can usually be ignored. The pest notes have more information, including options for how to manage them.

Pest

Masked Chafer 
(Golden brown beetle)
Cyclocephala spp.

Green fruit Beetle
Cotinis mutabilis

Hoplia Beetle
Hoplia callipyge

Damage
  • Larva feed on the roots of turfgrass
  • Animals can be attracted to infested lawns
  • Beetles chew soft maturing fruit
  • Larva feed in decomposing organic matter
  • Can attract animals
  • Beetles chew round holes in rose petals and other flowers, 
  • Larva eat leaves/roots of some other plants

Larvae size

1" long

Up to 2" long

.45" long

Beetle size

¾" long

Up to 1 ⅓" long

¼–.4" long

Notes

Damage appears in late summer or fall

Occasional pest of apricots, figs, peaches, and plums

Problem March–May when the beetles feed on light-colored blossoms

Life cycle

 Single generation per year

Management

Masked chafer Pest Note

Green fruit beetle Pest Note

Hoplia beetle Pest Note

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