Field Identification
Andean weevils that treat ulluco tubers like an all-you-can-eat starch bar—larvae tunnel flesh while adults notch leaves. Infestations spread with soil on tools, footwear, and saved seed tubers.
Small Premnotrypes adults are dull brown with a typical weevil snout; larvae are legless grubs inside tubers. Field symptoms include wilting from root feeding, ragged leaves, and corky holes when you slice open tubers.
How to Deal With It
Organic Control Methods
Neem and Beauveria bassiana applications targeting adults during evening activity; soil drenches with approved microbial products where organic certification permits.
Entomopathogenic nematodes in moist beds after harvest incorporation; encourage generalist predators in mulch-rich systems.
Rotate ulluco with non-hosts; use only clean propagation material; harvest carefully and cull infested tubers before storage; deep clean tools between plots.
Floating row cover over new plantings until vines establish; pitfall traps along bed edges; solarization of small nursery beds in sunny sites.
Inspect imported Andean germplasm; isolate new lines one season; monitor adults with white sheets shaken over foliage at dusk.
Let Nature Handle It
Natural Enemies
- Ground Beetles (Carabidae)
- Entomopathogenic Nematodes
- Entomopathogenic Fungi