Striped Cucumber Beetle

Acalymma vittatum — the striped cucumber beetle — is the SISTER PEST to the spotted cucumber beetle (Diabrotica undecimpunctata, already in the Wild Files) and one of about 70 species in genus Acalymma (the leaf beetles in family Chrysomelidae). The species is widespread across all of eastern and central North America from southern Canada south through the eastern US to Mexico (with closely-related Acalymma species in western NA and other regions). Adults are 5-6 mm long, with the species' diagnostic features: bright YELLOW ELYTRA marked by THREE BLACK LONGITUDINAL STRIPES (one central stripe down the middle, two lateral stripes along the sides — the source of the 'striped cucumber beetle' common name distinguishing from the spotted cucumber beetle which has spots), darker pronotum and head, and the typical leaf beetle (Chrysomelidae) body plan. The species and the spotted cucumber beetle commonly co-occur in cucurbit fields and gardens across NA, with both species causing significant damage. The species attacks CUCURBITS — cucumbers, melons (cantaloupe, watermelon), squash, pumpkins, zucchini, and other Cucurbitaceae crops — and (similar to spotted cucumber beetle) is the primary VECTOR of BACTERIAL WILT in cucurbits (caused by Erwinia tracheiphila). The two species share the same wilt-vectoring role and the same agricultural importance, with regional dominance varying by location and year. The species also attacks BEAN AND PEA crops as a secondary host. Adults feed on cucurbit leaves, flowers, and developing fruits, while larvae feed on cucurbit roots underground. Annual NA economic losses (combining both striped and spotted cucumber beetles plus the bacterial wilt damage they vector) total HUNDREDS OF MILLIONS OF DOLLARS across NA cucurbit production. The species is featured in essentially every modern textbook discussion of cucurbit pest management. Modern control approaches include: insecticide applications, BIOLOGICAL CONTROL with parasitoid flies, TRAP CROPPING (using attractive cucurbit varieties as trap crops), KAOLIN CLAY APPLICATIONS (white powdery clay sprayed on cucurbit foliage that repels feeding beetles), and integrated pest management. The species is harmless to humans (no bite, no sting) but is a major economic pest of NA cucurbit agriculture.