Spotted cucumber beetle
The spotted cucumber beetle's larva is also known as the southern corn rootworm, so the same insect is managed as two different pests depending on whether it is chewing leaves or roots.
| Where | Farmland, gardens and open fields |
|---|---|
| Size | 5 to 7 mm body length |
| When | March to November |
Adults are greenish yellow with a black head, a lime green thorax, and twelve black spots across the wing covers, growing to about 5 to 7 mm long. The similar banded cucumber beetle has a red head and greenish blue bands instead of spots.
Larvae feed underground on the roots of corn and other grasses, while adults feed on the leaves, flowers and fruit of cucumbers, beans and many other garden and field crops across most of the United States and southern Canada. Several generations can occur in a single growing season in warmer areas.
Traits
Habitat
Farmland
Colour
Yellow, Green, Black
Active
Day
To people
Does not bite or sting; harmless to handle, though it is a common crop pest.
Activity through the year
Often confused with
Has a red head and black thorax with three greenish blue bands crossing the wing covers, rather than the black head, green thorax and twelve black spots of the spotted cucumber beetle.
Questions
Is the Spotted cucumber beetle dangerous to people?
Does not bite or sting; harmless to handle, though it is a common crop pest.
When can you see the Spotted cucumber beetle?
The Spotted cucumber beetle can be seen from March to November, by day.
Plate retouched from a photo by Catherine C. Galley, CC BY 4.0, iNaturalist Licence
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Beetles›Leaf beetles›Diabrotica
Last updated 2026-09-26. Every entry is checked against published sources.