Insect
Mexican Bean Beetle
A copper-coloured ladybug-like beetle with 16 black spots; both adults and yellow spiny larvae skeletonise bean leaf undersides, leaving only the veins.
Symptoms to Look For
- Leaf undersides skeletonised, leaving a lacy pattern of veins
- Yellow spiny oval larvae clustered on leaf undersides
- Leaves turning brown and papery where feeding has occurred
Affected Plants
BeanSoybean
Organic Solutions
Neem oil spray
Spray neem oil solution onto leaf undersides where larvae feed, repeating every 7 days through the season.
Hand-picking
Remove yellow egg clusters from leaf undersides and crush larvae by hand during morning inspections.
Parasitic wasps
Release Pediobius foveolatus parasitic wasps to target larvae - highly effective when released during warm settled weather.
Prevention
- Clear bean debris immediately after harvest to remove overwintering habitat
- Plant a trap crop of soybeans at the garden edge to draw beetles away from snap beans
Garden, by Willowbottom recommends only organic, wildlife-friendly solutions. No synthetic pesticides, no harmful chemicals - ever.