Bean bug
Young nymphs mimic the shape and movements of ants, while adults reveal yellow and black stripes across the abdomen in flight that resemble a wasp.
| Where | Farmland across East and Southeast Asia |
|---|---|
| Size | 13 to 17 mm body length |
| When | April to October |
The Bean bug is a slender brown true bug with long hind legs and a narrow body, easy to overlook among grass stems. Its folded wings hide a yellow and black striped abdomen that becomes visible only when it opens its wings to fly.
Young nymphs are dark and ant shaped, copying the movement of ants for protection before growing into the wasp mimicking adult. It feeds on the seed pods of soybeans, cowpeas and other legumes, and is treated as a pest of bean crops.
Traits
Habitat
Farmland
Colour
Brown, Yellow, Black
Active
Day
To people
Releases a mild odor from a scent gland when disturbed but does not sting or bite; calm to observe.
Activity through the year
Often confused with
Nearly identical from above, but shows a clear yellow stripe along the side of the body when viewed from the side, which this species lacks.
Questions
Is the Bean bug dangerous to people?
Releases a mild odor from a scent gland when disturbed but does not sting or bite; calm to observe.
When can you see the Bean bug?
The Bean bug can be seen from April to October, by day.
Plate retouched from a museum specimen photo by Natural History Museum of Denmark, CC BY 4.0, GBIF Licence
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True bugs›Broad-headed bugs›Riptortus
Last updated 2026-09-27. Every entry is checked against published sources.