Insects That Attack Potato Plant Leaves

Potato plants are often targeted by insects, according to entomologist Ricky Foster at Purdue University. Some bugs will focus exclusively on the leaves of a developing or mature potato plant, eating and chewing to their hearts content if left unchecked. The results can be devastating for the plant and the plant's owner.

The larvae and the adult versions of the Colorado potato beetle will consume the leaves of a potato plant. Although these insects will dine on any of the plants related to the potato, such as eggplants and tomatoes, the potato is their favorite host plant. The adults have orange and yellow oval bodies with obvious black stripes on the coverings of their wings. The larvae vary from pink to red, with the older ones possessing two rows of blackened dots on each side. Once the adults emerge from overwintering in the ground, they make their way to potato plants, where they feed and lay their eggs. The hatched larvae start to grow and they too partake of the foliage. The main damage occurs from the latter stages of the larvae. The flowering potato plants feel the effects of this leaf defoliation the most. The Colorado potato beetle can develop resistance to certain insecticides, making it prudent to vary the types you use to combat them.

Potato leafhoppers are not typically a serious threat to potato plants in small numbers. This insect is in the area of 1/8 inch in length and is a greenish-yellow color. The leafhoppers reproduce throughout the warm months, with three to four generations of bugs possible. The leafhopper can damage potato plants by removing the juices from the leaves through its sucking mouthparts. One symptom of a leafhopper problem, known as hopperburn according to the San Luis Hills Farms website, manifests itself as a brown or yellow patch at the ends of the leaves. If leafhoppers continue to feed, the potato plant may suffer and its yield will be small. Insecticides can solve the leafhopper problems.

Only a large infestation of tiny flea beetles will hurt a potato plant. The flea beetle only grows as large as 1/16 of an inch long. The adults have a dark coloring, with big hind legs that allow them to leap away when threatened. This trait, and its size, gives the flea beetle its name. The flea beetle spends the winter months in plant debris near a potato field, coming out in spring to eat the leaves. The flea beetle's trademark is a small hole in the leaf. It takes many flea beetles to threaten a potato plant seriously, but if this does happen, insecticides can curtail any defoliation of the plants.

Aphids are problems for multiple crop plants, with potatoes often falling victim to these tiny bugs. As small as 1/20 of an inch, aphids have soft bodies and usually hide on the leaf's underside, where they suck fluids and juices from the leaves. As the aphid breeds and accumulates, it can cause severe wilting of the potato plant's leaves. Potato psyllids grow to 1/8 of an inch in length and look like miniature versions of the cicada. The nymphs do the most harm to potato plants, in part from a toxin that they can inject into the leaves while they feed upon them. The toxins cause abnormalities in the leaves. The lygus bug also feeds on leaves and produces a toxin that can distort their growth, while the false cinch bugs will also occasionally attack and eat potato leaves.