Irish Potato Pests

Matthew J. Blua, Silvia I. Rondon, Andrew Jensen, and Neil Bell
March 2020

Includes management options for commercial and home use.

In all cases, follow the instructions on the pesticide label. The PNW Insect Management Handbook has no legal status, whereas the pesticide label is a legal document. Read the product label before making any pesticide applications.

Note: Products are listed in alphabetical order and not in order of preference or superiority of pest control.

It is absolutely essential to consult pesticide labels for rates, timings, safety precautions, plant-back restrictions, etc. prior to making a recommendation or deciding on a treatment program. There are web resources available to search for labeled pesticides and to see specimen labels of products. Some of these include:—This is a database of all pesticides registered in Washington and Oregon. It is a thorough database with many search options but lacks a complete collection of specimen labels.

Copies of almost all pesticide labels can be found through the following sites. In addition, these companies offer searchable databases of products and which pests and crops are on their labels. These web resources allow thorough research on pesticide products prior to making recommendations or treatment decisions.

For general information on potato insect pests, see the following:

Special Note about Resistance Management and Secondary Pest Outbreaks

At least three of the important pests of potato are known worldwide for developing resistance to insecticides. Of particular concern are green peach aphid (Myzus persicae), Colorado potato beetle (Leptinotarsa decemlineata), and potato tuberworm (Phthorimaea operculella). To prevent further development of insecticide-resistant pest populations, it is very important that growers do not rely on products with a single mode of action. Of particular concern is the class of insecticides known as neonicotinoids (Group 4A in Tables 1-2 of this section). These are highly effective insecticides that can control many pests of potato all season long. However, resistance to this class of chemicals has developed in Colorado potato beetle in other parts of the U.S., and care must be taken to avoid the development of resistance in the PNW. If used at planting or as a seed treatment, neonicotinoid products should not be used again as a foliar treatment. Always avoid treating large contiguous areas with any single class of chemistry.

Pyrethroid insecticide (Group 3 in Tables 1-2) applications make pest management more difficult and can lead to outbreaks of aphids, thrips, and spider mites.