Biology and Economics of Recommendations for Insecticide-Based Management of Soybean Aphid

Abstract

Soybean aphid, Aphis glycines Matsumura, remains the key insect pest of soybean, Glycine max (L.) Merrill, in the north-central United States. Management of this pest has relied primarily on scouting and application of foliar insecticides based on an economic threshold (ET) of 250 aphids per plant. This review explains why this ET remains valid for soybean aphid management, despite changes in crop value and input costs. In particular, we review how soybean aphid impacts soybean yield, the role of biology and economics in recommendations for soybean aphid management, and the shortand long-term consequences of inappropriately timed insecticide applications.

Soybean aphid biotype 1 genome: Insights into the invasive biology and adaptive evolution of a major agricultural pest

“…For some U.S. states, as much as 57% of soybean acres have been reported as treated with insecticide during outbreak years (Ragsdale et al, 2007). Scouting and insecticide treatments based on economic threshold have been shown to be an economical way to manage soybean aphids with insecticide (Ragsdale et al, 2007(Ragsdale et al, , 2011Hodgson et al, 2012;Koch et al, 2016).…”

Optimizing band selection for spectral detection of Aphis glycines Matsumura in soybean

“…Cumulative aphid‐days are calculated as the area under the curve of aphid abundance over time during a chosen part of a growing season . In soybean, CAD can be used to prompt insecticidal treatments and prevent projected aphid abundance from reaching 5500 CAD, the economic injury level for soybean aphid . Sample estimates of CAD have also been used to quantify season‐long aphid populations in research trials evaluating insecticide efficacy and plant resistance to A. glycines .…”

“…25 In soybean, CAD can be used to prompt insecticidal treatments and prevent projected aphid abundance from reaching 5500 CAD, the economic injury level for soybean aphid. 26,27 Sample estimates of CAD have also been used to quantify season-long aphid populations in research trials evaluating insecticide efficacy and plant resistance to A. glycines. [28][29][30] Accurate estimation of CAD requires that aphids be counted directly on plants at weekly or biweekly intervals.…”

Resistance management plan for soybean aphid

“…The odds of making a profitable treatment decision are increased with regular scouting and applications made after exceeding the economic threshold (Johnson et al 2009, Hodgson et al 2012. The economic threshold is validated annually at Iowa State University (http://bit.ly/2erObl7) and is recommended regardless of fluctuating market values (Koch et al 2016).…”