Potato Pest Management
Potatoes give us endless foods and snacks—from chips to potato salad to fries. But potatoes aren’t just popular among humans. The vegetable is also a favorite of many pests, including beetles and caterpillars. Potato production does happen in Florida, particularly during the winter-spring crop, so Florida’s farmers should know what could damage their crops and how to manage potential threats.
Potato’s Insect Pests
Colorado Potato Beetles
As their name suggests, Colorado potato beetles mainly eat potatoes and other nightshades such as eggplants, apples, and tomatoes. The hump-backed larvae feed on leaves and can usually be spotted near the top of plants. Once the larvae are fully developed into adults after spending a week in the soil, they emerge and begin to feed on potato plants. Not only can their feeding damage plants, Colorado potato beetles also transmit spindle tuber virus and bacterial ring rot.
While adult click beetles don’t attack potatoes, the larvae, known as wireworms, eat both potato seeds and developing tubers. This feeding leads to wounds that allow disease-causing organisms to enter the seeds. Additionally, injury can occur when wireworms tunnel into the tubers, making the potatoes unmarketable.
Flea beetles usually don’t damage tubers, but their feeding does result in many small holes throughout leaves. These small “shot holes” can make potato plants susceptible to bacterial and fungal diseases such as Verticillium wilt and Fusarium rot.
A condition known as hopper burn occurs when leafhopper adults and nymphs damage leaves by sucking the sap on the underside. A toxin secreted as the leafhoppers feed makes the leaves curl, which is often confused with plant maturation. Hopper burn can also lead to stunted plants and reduced yields.
Although aphids are small, they can cause damage when they suck juices from the underside of potato plant leaves. These rapidly producing insects also transmit viruses from plant to plant.
From beet armyworms to cutworms and loopers, caterpillar-type pests cause damage to potato plants by feeding on leaves. Young larvae are known to feed on the undersurface of leaflets, while older larvae often create large holes that could eventually lead to secondary rots.
It is recommended that you alternate between insecticides from different chemical groups to reduce the likelihood of pests developing resistance. This method can also increase the effectiveness of individual applications. Rapid resistance may also occur if you apply less insecticide than recommended. Be sure to consider chemical costs and length of effectiveness when choosing the best insecticide for your potato plants.
Rotating crops may help reduce the number of pests, but this method can be difficult if you have limited land. If you effectively manage diseases and weeds in your potato plants and make sure they receive enough water, it will help minimize damage from insects—plants are more affected if they are under stress.
Bacillus thuringiensis, a reduced-risk insecticide that helps manage worms and loopers, can be a good alternative to chemicals. However, if the worms are larger or more mature, or if the population exceeds threshold levels, then synthetic insecticides would better manage these pests.
Potato Production Resources
For more information on growing crops in the state, please view the 2012-2013 Vegetable Production Handbook for Florida, which includes the chapter Potato Production in Florida.
Adapted and excerpted from:
R. L. Jacques and T. R. Fasulo,Colorado Potato Beetle, Leptinotarsa decemlineata (Say) and False Potato Beetle, Leptinotarsa juncta (Germar) (Insecta: Coleoptera: Chrysomelidae)( EENY146), UF/IFAS Entomology and Nematology Department (rev. 11/2012).
M. Mossler and C. Hutchinson, Florida Crop/Pest Management Profile: Potatoes (CIR1237), UF/IFAS Horticulture Sciences Department (rev. 03/2011).
C. E. Rouse and P. J. Dittmar, Factors Affecting Herbicide Use in Fruits and Vegetable (HS1219), UF/IFAS Horticulture Sciences Department (05/2013).
S.E. Webb, Insect Management for Potatoes (ENY469), UF/IFAS Entomology and Nematology Department (rev. 03/2010).
Related Sites & Articles
- Insect Management for Sweet Potatoes
- Nematode Management in Sweet Potatoes (including Boniatos)
- Nematode Management in Potatoes (Irish or White)
- Growing Potatoes at Home
- Entomology and Nematology Department
- Potato Production in Florida
- Potato Physiological Disorders - Brown Center and Hollow Heart
- UF Pest Alert