Cucumber · Symptom guide
Bugs on cucumber plants
Bugs on cucumber plants in a garden bed are a look-and-compare job. Cited sheets list cucumber beetles as observations, not a ranked or confirmed cause. This page does not diagnose, name a spray, or sell a treatment.
Cited observations are comparisons—not a confirmed diagnosis. Check the cited sources and local requirements before taking action.
Save this bed. See it coming next year.
Your checks stay in the Field Book so next season is not a guess.
Illustrative photograph — not identification proof.
Look
Compare the plant in front of you with the cited notes after Other causes. Holes in leaves or chewed flowers alone do not name a cause on this page.
Other causes
Growing notes live on how to grow cucumber. Garden-wide looks live on garden pests. Tomato hornworm is a separate species page — not this crop-pest list.
What the sources say — at a glance
One source per card. Facts are not averaged.
Clemson HGIC 1309 (South Carolina)
Cucumber beetles named on cucumber.
Details and limits (2)
Look
Clemson HGIC 1309 (South Carolina) names cucumber beetles on cucumber. Naming on that sheet — not a ranking and not a diagnosis.
Limit
South Carolina HGIC 1309. Naming-on-sheet only.
Maryland Extension (Maryland)
Adults 1/4 in. Larvae 1/2 in. Cucurbits. Chew holes. Row cover until bloom.
Details and limits (6)
Look
Maryland Extension (Maryland): adults up to 1/4 inch long with a black head. Spotted beetle is yellow-green with 12 black spots on the back. Striped beetle is yellow with three black longitudinal stripes on the back. Observation — not a diagnosis.
Look
Maryland Extension (Maryland): larvae are yellowish-white, 1/2 inch long, wormlike with dark heads. Observation — not a diagnosis.
Host
Maryland Extension (Maryland): host plants are cucurbits, including cucumber, squash, pumpkin, and muskmelon. Host as named — not a ranking.
Look
Maryland Extension (Maryland): adults chew holes in leaves, flowers, and fruit. Observation — not a diagnosis.
Method
Maryland Extension (Maryland): use floating row covers until they bloom. Remove once plants bloom. Method — not a prevention promise.
Limit
Maryland cucumber-beetle sheet. Observation, host, and method as named.
Illinois Extension (Illinois)
1/4 in. Black and yellow spotted or striped. Feed on foliage, flowers, stems or fruit.
Details and limits (2)
Look
Illinois Extension (Illinois): 1/4 inch long. Black and yellow spotted or striped beetles. Feed on foliage, flowers, stems or fruit. Observation — not a diagnosis.
Limit
Illinois cucumber page. Observation only.
UMN Extension (Minnesota)
About 1/5 in. Three vertical black stripes. Row cover early to mid-June.
Details and limits (3)
Look
UMN Extension (Minnesota): striped cucumber beetle about 1/5 inch long. It has yellow wings with three vertical black stripes. Observation — not a diagnosis.
Method
UMN Extension (Minnesota): floating row cover during early to mid-June. Remove when plants start flowering. Method — not a prevention promise.
Limit
Minnesota cucumber-beetle page. Observation and method only.
Sources differ
Make it yours
Save the bed in the Field Book so next season is not a guess.
How we know — methodology. Ranges and assertions are cited per source, not blended.