Colorado Beetle

From wild plants to potatoes

The Colorado beetle evolved on the buffalo bur (Solanum rostratum), a wild plant of the Great Plains. When potato cultivation expanded westward in the 1850s, the beetle found a far superior host plant and began spreading rapidly. By the 1870s it had reached the Atlantic coast of North America. European colonists accidentally transported it to France around 1921; from there it spread rapidly east across the continent, reaching Russia by the 1950s.

The damage

Both adult beetles and larvae feed voraciously on potato foliage. A heavy infestation can completely defoliate a field within days, causing catastrophic yield loss or total crop failure. The beetle has evolved resistance to dozens of insecticides over the decades — it is one of the most insecticide-resistant insects known, having developed resistance to carbamates, organophosphates, pyrethroids, and neonicotinoids.

Notifiable pest in Britain

Britain remains free of established Colorado beetle populations, and it is a notifiable pest: any suspected sighting must be reported immediately to the Animal and Plant Health Agency. Occasional individuals arrive on imported produce, but strict monitoring and rapid response have prevented establishment. Given Britain’s large potato-growing industry, an established population would be economically devastating.

WWII propaganda

During World War II, Germans produced propaganda accusing American aircraft of dropping Colorado beetles over German potato fields. Whether any such drops occurred is debated, but the beetle did spread rapidly east from France-based populations after the war.