Diabrotica

Diabrotica is a genus of leaf beetles in the family Chrysomelidae, subfamily Galerucinae, and tribe Diabroticini. The genus contains numerous species distributed mainly in North America, with some species having a broader range due to introductions. Members of this genus are commonly referred to as cucumber beetles and corn rootworms, reflecting their prominence as agricultural pests in cucurbit crops and maize.

Adults of Diabrotica species are typically small to medium-sized beetles, often 4–12 millimeters in length. Color patterns vary from yellow-green to brown, and many species display stripes or spots. The larvae are agroecologically important as root-feeders and develop in the soil. Larval feeding on plant roots, especially maize roots, can reduce nutrient uptake and yield; adults feed on foliage, flowers, and pollen.

Ecology and life cycle vary by species but often include eggs laid in soil near host plants, larval development in the soil, pupation, and adult emergence in warmer seasons. Some species complete one generation per year, while others may have two or more, depending on climate. A notable aspect of the genus is the economic impact on crops: corn rootworms (for example, Diabrotica virgifera virgifera and related taxa) are major pests of maize, while cucumber beetles feed on cucurbits and can transmit bacterial wilt pathogens.

Management typically relies on integrated pest management approaches: crop rotation to non-host crops to disrupt rootworm life cycles, soil or seed treatments, and the use of resistant or transgenic crops. Chemical controls are used selectively, and cultural practices such as timing and sanitation help reduce populations.

Notable species include the western corn rootworm (Diabrotica virgifera virgifera), the northern corn rootworm (Diabrotica barberi), and the sixteen-spotted cucumber beetle (Diabrotica undecimpunctata undecimpunctata).