What's Eating My Green Beans?
Bean damage runs from lacy leaves to vanished seedlings, and the suspect list includes one impostor that looks like a helpful ladybug. Look closely before you thank it.
The usual suspects
Mexican bean beetle
The signs: Leaves skeletonized to a lacy net, eaten from the underside so veins remain; damage builds through midsummer.
What it looks like: Adults look like large coppery-orange ladybugs with sixteen black spots; larvae are bright yellow, spiny, and do most of the eating. Yellow egg clusters stand on end beneath leaves.
What to do: Handpick adults and crush the spiny larvae and egg clusters — check leaf undersides twice a week. Plant an early crop to dodge peak pressure; remove spent plants immediately.
Japanese beetles
The signs: Leaves eaten to lace from the top down in broad daylight, beetles feeding in groups.
What it looks like: Metallic green heads with copper wing covers — unmistakable.
What to do: Knock into soapy water in the morning while sluggish. Skip the pheromone traps; they invite more than they catch.
Bean leaf beetle
The signs: Neat round holes in leaves and scarred pods, heaviest on seedlings and again at pod set.
What it looks like: Small reddish to yellow-green beetle with a black triangle behind the head.
What to do: Row cover at emergence; later plantings usually outrun the damage.
Aphids
The signs: Curled tips, sticky leaves, and clusters on tender growth.
What it looks like: Black or green colonies, often ant-attended.
What to do: Water blast and beneficials handle most years; soap for outbreaks.
Slugs
The signs: Seedlings shredded or gone overnight in damp weather, slime tell-tales nearby.
What it looks like: Night feeders under mulch.
What to do: Delay mulching until plants are up and growing; trap and bait around new rows.
Rabbits, deer, and groundhogs
The signs: Rows cropped to stubs in a single night — clean angled bites (rabbits), ragged torn stems head-high (deer), or wholesale flattening (groundhogs).
What it looks like: Volume is the giveaway; no insect empties a row overnight.
What to do: Low fencing flared at the base for rabbits, tall fencing or netting for deer, buried-skirt fencing for groundhogs.
When it's not a pest at all
Rust-orange powdery pustules on leaf undersides are bean rust, a fungus of humid spells. Distorted puckered new growth without insects present can be mosaic virus — pull and trash those plants.
Or just point your phone at it
Snap a photo of the leaf, the bug, or the droppings, and Harold — the advisor built into Homestead Paradise — names what he sees, tells you friend or foe, and what he'd do next. Honest when he's unsure, and careful where it counts.
Put Harold's Eyes on it — free 14-day trial