Field Identification
A true nut snout beetle whose grub turns kernels into powder and frass—often after the shell looks fine from the outside. Adults emerge from soil, feed on nuts, then lay eggs through punctures; larvae drop to pupate underground for two-year cycles in cooler areas.
Long-snouted dark beetles; crescent-shaped scars on shucks from feeding; pinholes where eggs were inserted. Infested nuts feel light and may rattle when larvae are large.
How to Deal With It
Organic Control Methods
Entomopathogenic nematodes (Steinernema carpocapsae, S. riobrave) applied to soil under canopy during larval drop and pupation windows—timing beats chemistry in organic blocks.
Same nematodes plus fungal pathogens (Beauveria, Metarhizium) on soil surface; chickens or guinea fowl under trees scratch larvae and pupae where permitted.
Shake or pole adult weevils onto sheets in July–August evenings; destroy infested nuts; maintain bare soil or short sod under trees during emergence to improve nematode contact.
Tree bands are ineffective for adults that fly; focus on ground treatments and sanitation.
Monitor with circle traps on trunks; track degree-days for emergence; harvest as soon as nuts mature to shorten exposure.
Let Nature Handle It
Natural Enemies
- Entomopathogenic Nematodes
- Entomopathogenic Fungi
- Ground Beetles (Carabidae)