Spotted Cucumber Beetle Identification Guide
Learn to identify the yellow-green beetle marked with twelve black spots often seen on garden vines.
Read the full Spotted Cucumber Beetle encyclopedia entry →
Key Visual Features
The spotted cucumber beetle is a small, elongated beetle about 5-7 mm long, with a yellow-green to greenish-yellow body marked by twelve distinct black spots arranged across the wing covers, which is why it is sometimes called the twelve-spotted cucumber beetle. The head is black or dark, and the pronotum (the plate behind the head) is typically yellow-green and unmarked, providing a clean contrast to the spotted elytra. The antennae are thread-like and dark, roughly half the length of the body, and the legs are slender.
Where and When You're Likely to See Them
This beetle is common across much of North America in gardens, farm fields, and meadows, particularly wherever cucurbits like cucumber, squash, and melon are grown, though adults also visit a wide range of other flowering plants. They are active from spring through fall, often seen on leaves, flowers, and stems during the day, especially in sunny weather. Adults are frequently found feeding on flower petals and pollen in addition to leaves, making them visible on many types of blooming plants beyond just cucurbits.
Similar-Looking Bugs
The spotted cucumber beetle closely resembles the striped cucumber beetle, but the two are easy to tell apart by pattern: the spotted form has rounded black dots on a yellow-green background, while the striped form has three bold black longitudinal stripes running down the wing covers instead of spots. It can also be confused with certain lady beetles that have a yellow background and black spots, but cucumber beetles have a more elongated, flattened body and longer antennae compared to the rounded, domed shape of lady beetles. Its larval stage, sometimes called the southern corn rootworm, is a slender white grub found in soil near plant roots and is not visible above ground like the adult.
Quick ID Checklist
- Small, elongated beetle, 5-7 mm long
- Yellow-green body with twelve black spots on the wing covers
- Black head contrasting with an unmarked yellow-green pronotum
- Found on cucurbit vines and flowering plants in gardens and fields
- Active from spring through fall, often visiting flowers as well as leaves
Frequently asked questions
How do I tell a spotted cucumber beetle from a striped one?
The spotted cucumber beetle has twelve rounded black spots on its wing covers, while the striped cucumber beetle instead has three solid black stripes running lengthwise, making the pattern easy to distinguish.
Are spotted cucumber beetles only found on cucumbers?
No, while they are common on cucurbits like cucumber, squash, and melon, adults also visit many other flowering plants to feed on petals and pollen.
What does the spotted cucumber beetle's larva look like?
The larva, sometimes called the southern corn rootworm, is a slender, whitish grub that lives in the soil near plant roots and is not typically seen above ground.
When are spotted cucumber beetles most active?
They are active from spring through fall, with sightings most common on warm, sunny days when adults are feeding or resting on leaves and flowers.
Spotted Cucumber Beetle identified by the community
Recent Spotted Cucumber Beetle finds identified with Bug Identifier.
