Masked Chafer Grub
Cyclocephala spp.
moderate risk
insect
Overview
White grubs that are major pests of turf grass. Adults are chafer beetles that do minimal damage themselves.
Larvae C-shaped white grubs 20-25mm with brown head. Adults tan/brown beetles 12-15mm. Larvae identified by raster pattern.
Prevention Strategies
- •Allow turf to dry between waterings in July to deter egg-laying
- •Resistant grass varieties
- •Beneficial nematodes applied in August-September
Control Methods
- •Imidacloprid (Merit) preventatively in June-July
- •Chlorantraniliprole (Acelepryn) preventatively April-May
- •Beneficial nematodes (Heterorhabditis bacteriophora) applied in warm wet conditions
- •Milky spore (Bacillus popilliae) for long-term organic control
Interesting Facts
- •Grubs in lawn indicate healthy soil - but too many indicate imbalance
- •Secondary wildlife damage (skunks digging) often worse than grub feeding itself
- •Preventative insecticide treatment is far more effective than curative
- •Milky spore provides years of natural control once established