Crop & Pest Report


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Scout for Pea Aphids (07/19/18)

Pea aphids are increasing in pulse crops in north central and northwest ND.

Scout for Pea Aphids

Pea aphids are increasing in pulse crops in north central and northwest ND (source:  Pulse Crop Survey). Pea aphids are small, about 1/8+ inch long and pale to dark green with reddish eyes. Aphids suck the sap from plants and may vector viral diseases. Pulse crops are especially susceptible in the flowering and early pod stage, and damage can result in lower yields due to less seed formation and smaller seed size. Protein content and other quality issues do not appear to be affected by pea aphid feeding.

Look for pea aphids on the undersides of leaves and near leaf tips. Scout using a sweep net or examining the number of pea aphids per plant tip when 50 to 75 percent of the crop is flowering. Take at least ten 180-degree sweeps using a 15-inch sweep net or check five 8-inch plant tips from four distinct locations in the field.

Economic thresholds vary, depending on the value of the crops and cost of control. Control applied at the early pod stage provides protection through the pod formation stages, which are sensitive to aphid feeding injury.

Field pea: Insecticide treatment should occur when two to three aphids per 8-inch plant tip, or nine to 12 aphids per sweep (or 90 to 120 aphids per 10 sweeps). When virus is suspected or known to be present in migrating aphids, aggressive treatment with insecticides is prudent.

Lentil: Insecticide treatment for pea aphid control should be considered (1) when you reach an economic threshold of 30 to 40 aphids collected per 180-degree sweep of a 15-inch-diameter insect net, (2) when few natural enemies are present and (3) when aphid numbers do not decline during a two-day period.

Chickpea: No economic threshold is available for pea aphids.

See the new NDSU Extension publication Pulse Crop Insect Diagnostic Series E1877 for more information at


Janet J. Knodel

Extension Entomologist

This site is supported in part by the Crop Protection and Pest Management Program [grant no. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed are those of the website author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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