The impact of Lygus Species Feeding on Potatoes Grown in the Columbia Basin

Jennifer Darner

doi:10.7273/000007036

Potato is a high value crop grown in the Columbia Basin. Its marketability depends on consistent yields of quality potato tubers and anything that compromises this can mean lost revenue to commercial potato farms. Lygus bugs were once considered a minor pest of potatoes in the Columbia Basin; their feeding occasionally damaged buds and wilted leaves but generally did not affect yield. In the last several years, however, growers have reported an increased presence of lygus bugs in their fields and more extensive damage to potato plants. In 2018 and 2019, surveys were conducted to determine which species of lygus bugs were infesting potato fields in the Columbia Basin of Washington State. Two species were identified, Lygus hesperus and Lygus elisus, from the 29 fields sampled and the 710 specimens collected. There was a significant correlation between the latitude of the sample site and the number of each lygus bug species collected there, with L. elisus found predominantly in fields north of Othello, WA, and L. hesperus found mostly in fields south of Othello. There was also a correlation between the longitude of the sample site and the number of L. elisus found there, with most of them collected from fields in the west. Trials were conducted in Plymouth, WA in 2018, and in Pasco, WA from 2019 to 2021, to assess lygus bug feeding damage to potato foliage, and to evaluate the effect on tuber yield and quality. In 2018, cages were placed over potato plants to either exclude or trap lygus bugs. The potato plants that were exposed to lygus bugs accumulated significant damage from lygus bug feeding, and they senesced earlier than the caged plants without lygus bugs. There were no significant yield differences between caged potatoes with or without lygus bugs. In the 2019-2021 trials, caged potato plants were infested with lygus bugs at different potato growth stages (flowering, row closure, early tuber bulking, and late tuber bulking) with a non-infested cage as a control treatment. Lygus bugs that were infested early, especially around the tuber initiation and flowering stages, consistently caused more damage to potato plants than infestations that initiated at the late tuber bulking stage. Few conclusions could be made from the yield and tuber quality assessments, probably due to uncontrolled disease and weed infestations in some of the cages.

The impact of Lygus Species Feeding on Potatoes Grown in the Columbia Basin

Files and links (1)

Abstract

Metrics

Details