The species Leptinotarsa decemlineata is commonly known as the Colorado potato beetle and can be found infesting crops such as potatoes, tomatoes, eggplant and peppers (in general, Solanaceae Plants). All stages of growth of L. decemlineata feed mostly on foliage, chewing irregular holes in and along leaf margins, but may also attack stems. High populations can completely defoliate plants throughout large portions of a field. Extensive feeding at any time during the season, especially when the crop is in bloom, can significantly reduce yield and cause serious losses.
The adult Colorado potato beetle is approximately 10 mm long and 7 mm wide. Its head and pronotum (‘neck’) are brown-orange to yellow and covered with variously shaped black markings. Ten black lines run the length of the wing covers (elytra), which are otherwise yellow. Females can be recognized by their greatly distended abdomen and the absence of a depression in the last abdominal segment when viewed from below. The eggs are elongate and yellow to orange. They are usually laid on the underside of leaves of the host plant in clusters of about 30. The larva is humpbacked, and red-orange with two rows of black spots along the sides of the body.
Scouting for the presence of this species should take place early in the spring. Focus on the underside of leaves for the presence of eggs. Also, record the number of insects present and their distribution throughout the plot noting any areas of particularly high population levels. The area should be rechecked every 2 to 3 days, as the presence of the insect is detected, in order to avoid any population increase that can affect the crop.