Field Identification
A major Andean pest whose larvae mine tubers and adults climb plants to feed on foliage—turning subsistence potato patches into weevil daycare. Outbreaks track fields where infested tubers or soil are moved around.
Gray-brown snout beetles roughly 5–7 mm; C-shaped white grubs with brown heads bore in tubers leaving galleries and frass. Damage peaks where crop debris and soil harbor overwintering adults.
How to Deal With It
Organic Control Methods
Neem-based products and entomopathogenic fungi (Beauveria bassiana, Metarhizium) directed at adults on foliage and at soil-contact stages—repeat after rain when labels allow.
Entomopathogenic nematodes (Steinernema, Heterorhabditis) against pupae and larvae in moist soil; preserve ground beetles and field crickets that scavenge eggs and weak adults.
Deep plowing or timely tillage to bury adults; rotate out of solanaceae; use clean seed tubers; harvest promptly and remove cull piles; solarize or flood fields where feasible in highland systems.
Trenches with vertical plastic barriers; hand collection at peak adult flights; sift soil from infested lots before moving machinery.
Quarantine seed potatoes; pheromone or food-baited traps for monitoring; destroy volunteer potatoes that bridge generations.
Let Nature Handle It
Natural Enemies
- Ground Beetles (Carabidae)
- Entomopathogenic Nematodes
- Entomopathogenic Fungi
Threat Map