Pest description and crop damage Stink bugs that damage potatoes are usually large (0.37 inch), green, shield-shaped bugs. In the Columbia Basin, Chlorochroa is a common genus affecting potatoes. They feed by sucking plant sap. Stink bug damage is usually a flagging of leaflet, leaf, or stem. For example, damage caused by feeding at the base of a leaf can cause the entire leaf to wilt. Stink bugs are pests of potatoes in isolated pockets in the PNW. It is important to note that there are two species of large stink bugs in potatoes that are predators of Colorado potato beetle and caterpillars. Photos of these beneficial stink bugs can be seen at: http://www.nwpotatoresearch.com/IPM-StinkBugs2.cfm .
Biology and life history Stink bugs colonize potatoes from other crops and from native plant communities. Eggs are laid in masses of a few dozen at a time. Nymphs can develop quickly and form large populations under the right conditions. Little is known about what leads to stink bug outbreaks in potatoes, such as the primary source of potato-infesting bugs, preferred alternative hosts, etc.
Scouting and thresholds Stink bug adults often congregate in potato fields, gathering together in large groups on small patches of plants. Therefore, detecting an infestation can be challenging, but on the other hand finding a congregation of bugs in one small area may lead to incorrect assumptions about the level of infestation throughout the field. Stink bug adults and nymphs are both easily detected during normal scouting operations using a beating sheet/tray.
Like most pests of potatoes, stink bugs are preyed upon primarily by the many generalist predators living in most potato fields. There are also commercially-available parasitoids.
Management-chemical control: HOME USE
- azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
- insecticidal soap-Some formulations are OMRI-listed.
- kaolin-Applied as a spray to foliage it acts to repel certain insect pests. Some formulations are OMRI-listed for organic use.
- pyrethrins (often as a mix with other ingredients)-Some formulations are OMRI-listed for organic use.
Note: Pyrethroid insecticide (Group 3 in Tables 1-2) applications make aphid management more difficult and can lead to outbreaks of spider mites.
Management-chemical control: COMMERCIAL USE
Pyrethroid insecticide (Group 3 in Tables 1-2) applications make aphid management more difficult and can lead to outbreaks of spider mites.