Original illustration by PestControlBasics.com. Use anatomical labels above to confirm your identification.
🔍 Identification
Striped cucumber beetle (Acalymma vittatum): 6mm; yellow with 3 black stripes on wing covers; found east of Rockies primarily. Western spotted cucumber beetle (Diabrotica undecimpunctata): 8mm; yellow-green with 12 black spots; found throughout US (also called corn rootworm beetle in larvae stage). Both feed on: cucumber, squash, melon, beans, corn. Both vector Erwinia tracheiphila (bacterial wilt in cucumbers and melons) — transmitted through feces.
🧬 Biology & Behavior
Bacterial wilt transmission is the primary concern. Once transmitted, bacterial wilt causes rapid wilting and plant death within 2-4 weeks — no treatment cures it. Only preventive control of beetles prevents bacterial wilt. Row cover is the only fully reliable prevention for bacterial wilt — it physically excludes beetles. Chemical control reduces beetle populations but doesn't eliminate transmission risk.
⚠️ Damage & Health Risk
Adult feeding damage on flowers, pollen, and leaves; larval damage to roots (corn rootworm larvae are the same species); bacterial wilt transmission killing cucumber and melon plants; economic losses in commercial production.
🔧 DIY Treatment
Row cover until flowering (remove during bloom to allow pollination); kaolin clay applied to plants deters feeding; trap crops (Blue Hubbard squash draws beetles away from main crop); pyrethrin or spinosad spray on beetles present in the garden. Sticky yellow traps for monitoring.
👷 When to Call a Pro
Commercial cucurbit production: spray programs timed to adult emergence at vine emergence; threshold monitoring with sticky traps guides application timing.