Colorado potato beetle

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NR - Unranked

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Colorado potato beetle is relatively small for a beetle but relatively large for a leaf beetle. It is a serious crop pest to potato growers. The insect rapidly evolves resistance to chemical pesticides. Many insecticides that once successfully controlled the beetle are no longer effective.

Adults are broad-bodied, ¼″ to 7 ⁄16″ long, and about ⅛″ wide. The body is oval when viewed from above (dorsally) and strongly convex when viewed from the side (laterally).

The hardened plate on the upper side of the thorax (pronotum) is orangish-yellow to yellowish-brown and three times as wide as long, nearly as wide as the base of the hardened forewings (elytra). The are two black longitudinal marks in the middle that often join to form a V-shape, and several smaller black spots on each side.

The elytra are long and cover the tip of the abdomen. They are pale yellow with a black inner margin and five black longitudinal lines on each side. The small triangular plate at the base of the elytra (scutellum) is black.

The head is yellowish-brown with a small triangular black mark in the middle. It is partially visible when viewed from above. The antennae are short, less than half as long as the body, and widely separated at the base. They are weakly clubbed (clavate), gradually enlarged as they approach the tip. The eyes are black and are not notched.

The legs are mostly yellowish-brown. The last part of each leg (tarsus), corresponding to the foot, is black and has five segments. The fourth segment is very short and is concealed within the broadened tip of the third segment, making the tarsus appear to have only four segments.

The larva is very plump, strongly convex, and brick red when young, becoming pink and finally orange as it ages. It is about ½″ long when mature. It has two rows of black spots on each side, a black head, and six black legs.

Total length: ¼″ to 7 ⁄16″

No similar species in Minnesota

Open grasslands, agricultural fields

Two overlapping generations: May to the end of the host plants growing season

The female deposits masses of usually 20 to 60 bright orange eggs on the lower surface of leaves of host plants. After hatching the larvae pass through five distinct stages (instars). Mature larvae burrow ¾″ to 2″ into the soil to pupate. Adults of the second generation burrow shallowly into the soil to overwinter.

Larvae are found on the same species that adults feed on.

Leaves of mostly potato but also other plants in the Solanum genus.

Sources

24, 27, 29, 30, 82, 83.

Prior to European settlement the Colorado potato beetle was found only in Colorado and neighboring states. The potato was introduced into North America in the 1600s and began to be widely grown in the early 1700s. By 1840 the potato reached the insects home range. By 1859 the insect had switched to the potato as its preferred host, and by 1874 it had spread all the way to the east coast. It is now present across North America, Europe, and Asia.

Common and very widely distributed

Crawling on the exterior of our living room window. Left before we could capture.

landed on my deck

How can we control this pest safely?

Location: 6405 296th St. E., Cannon Falls, MN 55009

Crawling on the exterior of our living room window. Left before we could capture.

Location: Hutchinson MN (Mcleod Co.)

Location: Sturgeon Lake in Pine County

landed on my deck

Location: Farmington MN

How can we control this pest safely?

For methods to control this insect in a garden without chemical pesticides, you can find some recommendations at The Spruce. Here is the link:

How to Get Rid of Colorado Potato Beetle Infestations Organically

Location: Woodbury, Minnesota

Location: Woodbury, Minnesota

Location: Woodbury, Minnesota