The common term “potato bug” often sparks curiosity about the creature it describes and the origins of its name. While the name suggests a connection to potato plants, the exact reasons are not always clear. Understanding this insect, its feeding habits, and its historical interaction with agriculture reveals why it earned such a distinctive common title.
Identifying the “Potato Bug”
The “potato bug” refers to the Colorado Potato Beetle, scientifically known as Leptinotarsa decemlineata. This insect is identifiable by its distinctive appearance, typically measuring about 10 millimeters (3/8 inch) long with an oval, convex body. Its wing covers feature a bright yellow or orange background adorned with ten bold black stripes running lengthwise, giving rise to its species name, decemlineata, meaning “ten-lined”.
The term “potato bug” can sometimes be mistakenly applied to other creatures. These include sowbugs and pillbugs, which are not insects but rather terrestrial crustaceans, more closely related to crabs and lobsters. Another unrelated insect sometimes called a “potato bug” in some regions is the Jerusalem cricket.
Dietary Habits and Agricultural Impact
The Colorado Potato Beetle earned its name due to its dietary preference and agricultural impact. This beetle primarily feeds on plants belonging to the Solanaceae family, commonly known as the nightshades, with potatoes (Solanum tuberosum) being a preferred host. Originally, in its native Rocky Mountain range, the beetle subsisted on wild nightshade species such as buffalo bur (Solanum rostratum).
Both adult Colorado Potato Beetles and their larvae are voracious feeders, consuming the leaves of potato plants. This feeding activity leads to significant defoliation, which can severely reduce crop yields or even result in complete plant death if infestations are left unmanaged. A single larva can consume up to 40 square centimeters of potato leaves, while an adult beetle can eat approximately 10 square centimeters of foliage per day.
The Origin of the Common Name
The Colorado Potato Beetle’s expansion explains the origin of its common name. The beetle originated in the Rocky Mountains of North America, where it initially fed on various wild nightshade plants. As European settlers moved westward and began cultivating potatoes in the mid-19th century, the beetle adapted to this new and abundant food source.
Around 1859, the beetle began devastating potato crops in regions like Omaha, Nebraska, and subsequently spread rapidly eastward across North America with potato cultivation. This swift and destructive impact on potato fields made the beetle highly noticeable to farmers and the general public. The name “potato bug” thus emerged from direct observation, succinctly describing the insect’s prominent association with and damaging effect on potato plants.