Spotted Cucumber Beetle

Diabrotica undecimpunctata — the spotted cucumber beetle — is one of the most economically important AGRICULTURAL PESTS in North America and one of about 400 species in genus Diabrotica (including the western corn rootworm Diabrotica virgifera, already in the Wild Files). The species is widespread across all of North America from southern Canada south through the eastern and central US to Mexico. Adults are 5-7 mm long, with the species' diagnostic features: bright YELLOW-GREEN ELYTRA marked by 11 BLACK SPOTS (the species name 'undecimpunctata' is Latin for 'eleven-spotted' — referring to the diagnostic spot count), darker pronotum and head, and short clubbed antennae. The 'spotted cucumber beetle' common name and species name 'undecimpunctata' both reference the conspicuous spots, distinguishing the species from the related STRIPED CUCUMBER BEETLE (Acalymma vittatum) which has black-and-yellow longitudinal stripes rather than spots. The species is a major economic pest of CUCURBITS — cucumbers, melons (cantaloupe, watermelon, honeydew), squash, pumpkins, zucchini, and other Cucurbitaceae crops. Adults feed on cucurbit leaves, flowers, and developing fruits, while larvae feed on cucurbit roots underground. The species is also a MAJOR PEST of corn (larvae also feed on corn roots — the species is sometimes called the 'southern corn rootworm' for this corn-feeding role; the closely-related Western corn rootworm Diabrotica virgifera is the more economically important corn pest), beans, peanuts, soybeans, and many other crops. The species is the primary VECTOR of BACTERIAL WILT in cucurbits — caused by the bacterium Erwinia tracheiphila, which is transmitted from infected to healthy cucurbit plants by spotted cucumber beetle feeding. Bacterial wilt causes systemic plant wilt and rapid plant death, often within 1-2 weeks of initial infection, devastating affected cucurbit crops. Annual NA economic losses to spotted cucumber beetle (combining direct feeding damage on cucurbits and corn, and bacterial wilt damage) total HUNDREDS OF MILLIONS OF DOLLARS. Modern control approaches include: insecticide applications timed to adult and larval activity, BIOLOGICAL CONTROL with naturally-occurring parasitoid flies (Celatoria spp. tachinid flies), TRAP CROPPING (using highly-attractive cucurbit varieties as 'trap crops' to draw beetles away from main crops, then treating the trap crops with insecticide), and integrated pest management. The species is harmless to humans (no bite, no sting) but is a major economic pest of NA agriculture.