Potatoe pest control - Ask Extension
I believe I have "wireworms" eating into the flesh of my potatoes. The tubular's have divots that look like something is chewing on them. ...
Knowledgebase
Potatoe pest control #923264
Asked January 02, 2026, 1:04 PM EST
I believe I have "wireworms" eating into the flesh of my potatoes. The tubular's have divots that look like something is chewing on them. The size of the chewed area is about the size of the tip of my finger or thumb.
I am looking on how to treat the plant or soil to eliminate the wireworms
Washtenaw County Michigan
Expert Response
Since wireworms take such a long time to develop, they are a challenge to eradicate once established in the soil. There is no practical way to control them once potatoes are planted in the field. If you are growing them commercially, there are pre-planting soil treatments with bifenthrin that can be applied. There are not pre-treatment chemical options that are registered for the home gardener.
If you are considering planting potatoes, there is a way to sample and check the severity of the issue:
To sample, dig down about 10 inches and lift the shovel of soil for examination. Round the soil sample off to approximately 6 inches in diameter. Sift through at least 20 shovels of soil from different locations in the field to check for wireworms. An average of one wireworm per shovel of soil indicates a population of more than 20,000 wireworms per acre. A suggested economic injury level for corn is an average of 2 or more wireworms per 10 shovels of soil.
If you are considering planting potatoes, there is a way to sample and check the severity of the issue:
To sample, dig down about 10 inches and lift the shovel of soil for examination. Round the soil sample off to approximately 6 inches in diameter. Sift through at least 20 shovels of soil from different locations in the field to check for wireworms. An average of one wireworm per shovel of soil indicates a population of more than 20,000 wireworms per acre. A suggested economic injury level for corn is an average of 2 or more wireworms per 10 shovels of soil.
