- Worldwide. Sub-tropics and tropics. On beans of many kinds - Vigna, Phaseolus, and weeds.
- Eggs in seedling leaves hatch, and larvae tunnel to the midrib, then to the petiole and lower stem.
- Plants wilt, are stunted, or may fail to yield.
- Natural enemies: parasitoid wasps.
- Cultural control: remove volunteers and weeds; avoid overlapping crops; hill-up 2-3 weeks after germination (damage stimulates roots) ; mulch to encourage root formation; tolerant varieties.
- Chemical control: commercial growers – treat seed (e.g., imidacloprid); or spray plants (dimethoate).