Climbing commodity prices and increased drought conditions are good reasons to treat soybean aphids before they reach traditional threshold levels, says Matt Hubsch, Lead Agronomist for Legend Seeds. 
"Soybean aphids drain the plant of valuable carbohydrate stores. In ideal growing conditions, plants can manufacture a steady sugar supply to keep the plant healthy. However, in the current drought conditions, plants cannot keep up and the stress can result in costly financial losses – especially in the current commodity markets," Hubsch said.
Although the University recommended economic injury level (EIL) is 250 aphids per plant, with 80 percent of the plants infested; in today’s economic climate, Hubsch recommends the EIL threshold be decreased.

"There is no magic number. However, I encourage soybean growers to treat their fields when aphid populations reach 150 to 175 per plant," he said.
When treating, Hubsch reminds growers that synthetic pyrethroids can encourage flare ups of spider mites. To prevent this, he says growers should consider adding an insecticide designed to target spider mites to their tank mix.
If you have any questions on when to treat soybean aphids, or which products will work best in your fields, contact your local Legend Sales Agronomist for unbiased agronomic information.