Colorado Potato Beetle Biology
The Colorado Potato Beetle, Leptinotarsa decemlineata, is a member of a genus of more than 40 species located throughout North and South America. It is believed that the Colorado potato beetle shifted its food source from wild Solanaceous plants in the southwest of North America to potato plants, then spread throughout the continent, then on to Europe and Asia--wherever potatoes grow.
Colorado potato beetles as adults have a characteristic yellowish-orange back with five black or brown stripes running down each elytra, and is orange with back spots otherwise. Adults are oval-shaped and 3/8 inches long. Larvae are red with black legs and two rows of black spots on both sides. Pupae are lighter red or orange, and eggs are bright orange and football-shaped, laid in clusters of 20-45 on the underside of potato leaves.
Colorado potato beetles as adults have a characteristic yellowish-orange back with five black or brown stripes running down each elytra, and is orange with back spots otherwise. Adults are oval-shaped and 3/8 inches long. Larvae are red with black legs and two rows of black spots on both sides. Pupae are lighter red or orange, and eggs are bright orange and football-shaped, laid in clusters of 20-45 on the underside of potato leaves.
Colorado potato beetle larvae
Colorado potato beetles are holometabolous and females have a high fecundity at about 500 eggs in their lifespan. There can be one to three generations per year, depending on temperatures. Beetles that emerge during the shorter photoperiod later in the summer overwinter in the soil or in wooded perimeters around fields before their reproductive systems or flight muscles develop. They will re-emerge when potatoes are planted again, and can fly for about a mile. Upon colonization, the beetles lay eggs within 5 to 6 days. After about 10 days, larvae emerge and eat voraciously. In about 21 days, Colorado potato beetle larvae drop from the leaves of the potato plant to burrow under the soil to pupate for a week to ten days, then emerge as adults.
The Colorado Potato Beetle is the most important defoliator of potato plants, but also can feed on eggplant and tomato leaves. Defoliation of potato plants reduces yields and can even kill the plant. The adults can eat almost ten square centimeters of foliage a day, and the larvae can eat an amazing 40 square centimeters a day. Unfortunately, the beetles are very quick to develop resistance to pesticides. A species of Ladybird beetle, Coleomagilla maculata, and the predaceous stinkbug eat Colorado potato beetle eggs. Hand-picking and row covers are most effective in personal gardens for control, while crop rotation and spacing are used in larger-scale potato productions.