PHOTO: Scott Bauer/USDA Agricultural Research Service
Kevin Fogle
September 12, 2016

Although the cucumber beetle is a pest commonly known among gardeners, there are actually several various cucumber beetle species that have different physical appearances and behavioral patterns, meaning that each species requires a unique treatment approach. The striped cucumber beetle is one set of species to look out for. It’s commonly found in many parts of North America and feeds nearly exclusively on cucurbit crops, like cucumbers, melons and squash. The striped cucumber beetle population is actually composed of two closely related and nearly identical species: the western striped cucumber beetle (Acalymma trivittatum) and the eastern striped cucumber beetle (Acalymma vittatum).

Not To Be Confused With The Corn Rootworm Beetle

Adult striped cucumber beetles will grow to about 1/4 inch long with a rather narrow body. It has light-colored legs, wing covers (elytra) that are bright yellow to greenish-yellow, and as their name suggests, a series of three long, dark stripes that run the length of the insect from the back of the thorax to the rear of the abdomen. Watch out for its doppelganger, the western corn rootworm beetle, which is quite similar in appearance but features a pale-colored abdomen with three less-defined longitudinal stripes and dark-colored legs.

A Taste For Cucumbers

Unlike its cousin, the spotted cucumber beetle, which is a non-specific feeder eating a wide range of economic crops, the striped cucumber beetle exclusively feeds on cucumbers and related vegetables, eating the vegetation from early emergence to flowering. Once the flowers open, the beetles will begin to target the flowers and pollen. High populations of these pests will overwhelm and kill young seedlings, but established plants will likely survive—though their productivity will be reduced.

While the feeding by the striped cucumber beetle can be quite troublesome, there is a second issue. The striped cucumber beetle is a major vector for bacterial wilt disease that can be more destructive than feeding by beetles alone. If any plants show evidence of bacterial wilt, remove them immediately from your fields so that feeding beetles will not have a greater chance of spreading this untreatable plant disease.

Controlling Striped Cucumber Beetles

For organic gardeners, the best control of this pest comes from physical exclusion via row covers (where feasible) and good garden upkeep. Removing weeds from in and around the garden will help remove beetle habitat, as well as potential sources of the bacterial wilt. Mulching around your crops will help discourage female cucumber beetles from laying eggs at the base of plants. Finally, be certain to remove all dead vegetation and leaf litter from your cucurbits to remove a common overwintering site for adult beetles.


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