Milky spore for lawn grubs
Most lawns have more than one grub species. The commercial strain of milky spore infects only Japanese beetle grubs, so it can do nothing about masked chafer, European chafer or May/June beetle grubs. Kentucky Extension says masked chafer, May and June beetle grubs are unaffected, and that the product gave poor results even against Japanese beetle in its trials. Identify the grubs by the raster pattern before spending money. Kentucky Extension also says no biological product gives reliable white grub control; insect-parasitic nematodes such as Heterorhabditis bacteriophora are the other biological option, and work better in moist soil.
Before you order
A powder of bacterial spores spotted onto the lawn and watered in. Japanese beetle grubs that eat the spores can develop fatal milky disease. It does not affect any other lawn grub, and in university trials the commercial products gave poor control. How it works, how to tell it has established and the supplier list are on the full Paenibacillus popilliae profile.
Other controls for white grubs
- Heterorhabditis bacteriophoraNematode · 250k–500k /m² (1–2 billion per acre) for Japanese and Oriental beetle grubs; BASF gives European chafer 0.5–1 million /m²
- Ground beetlesWild predator · wild, attract it
- Rove beetlesWild predator · wild, attract it