Cucumber beetles on melons
Melons split in two here. Muskmelon and cantaloupe are susceptible to bacterial wilt, which the beetles carry into their feeding wounds, so Minnesota Extension sets the bar at half a beetle per seedling and one per older plant, all season. UF/IFAS says watermelon is not affected by bacterial wilt, and Wisconsin tolerates five beetles per plant on it. Keep row cover on until the first flowers, then take it off for the bees. Wisconsin names the cantaloupes 'Makdimon' and 'Rocky Sweet' as less attractive to the beetles. On honeydew, crenshaw and casaba, UC IPM adds a later problem: adults scar the underside of the fruit until the skin hardens.
At a glance
- Damage
- Chewed seedlings and flowers; vines that wilt from bacterial wilt
- Type
- Chewing · virus vector
- Settings
- Garden, Field
- Threshold
- ½ beetle per seedling, 1 per older plant (UMN); 5 per plant on watermelon (Wisconsin)
- Ally
- Carabidae
- Rate
- Nothing to release — ground beetles and wolf spiders reduce numbers (JIPM)
How to confirm it
A beetle about 3/16–1/4 inch (5–7 mm) long, yellow to yellow-green with three black stripes running down the back and a dark head. It sits on cucurbit seedlings, in flowers and under leaves. Twelve black spots instead of stripes is the spotted cucumber beetle.
Identification, lifecycle, degree days and every control option are on the full Striped cucumber beetle profile. Not sure it is this pest? Answer four questions about the damage.