Temperatures around 70 degrees Fahrenheit are optimal for soybean aphids and significantly higher temperatures will impede population growth.
A threshold-based sampling method exists, called Speed Scouting. The method is formally referred to as a binomial sequential sampling plan. The binomial refers to two possible outcomes when you look at a randomly selected plant (e.g., Yes or No; Infested or Not Infested). The sequential sampling aspect refers to the process of keeping track of what plants are and aren’t infested (based on the model’s definition of “infested”) and being able to conclude, often times quickly, whether you need to treat or not.
Growers are encouraged to be watchful for this pest in eastern Kansas, but to resist the temptation to treat until populations exceed established thresholds (around 50 aphids per leaflet in vegetative plants, and 250 aphids per plant from onset of bloom through pod fill). This threshold incorporates an approximate 7-day lead-time between scouting and treatment to allow time for spray arrangements or weather delays. Soybeans in early reproductive stages appear most susceptible to yield Ground cloth sampling method Vertical beat sheet method2 K-State Research and Extension loss that takes the form of reduced pod numbers. Aphid populations on maturing plants are typically in decline and producing winged forms that will leave the field. Treating these fields generally is not justified.
Biological control from predatory ladybeetle species and parasitoids.
This content is replicated from a Kansas State University Agricultural Experiment Station and Cooperative Extension Service Publication, MF743, dated January 2015. This information may not apply to pest management for states other than Kansas.
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Insecticide |
Rate |
|
|
Acephate (selected formulations of Acephate, Bracket, and Orthene) |
(See supplemental labels for formulations and rates.) |
|
|
Acetamiprid plus bifethrin (Justice) |
0.0351 to 0.0422 lbs. a.i/acre (2.5 to 3.0 fl. oz./acre) |
|
|
Alpha-cypermethrin (Fastac EC) |
2.8 to 3.8 fl oz./acre |
|
|
Beta-cyfluethrin (Baythroid XL) |
0.0155 to 0.022 lbs. a.i./acre (2.0 to 2.8 fl. oz.) |
|
|
Bifenthrin plus imidacloprid (Tempest) |
0.06 to 0.095 lbs. a.i./acre (3.8 to 6.1 fl. oz./acre) |
|
|
Chloropyrifos (Lorsban 4E) |
1 to 2 pints/acre |
|
|
Chloropyrifos plus gamma-cyhalothrin (Cobalt) |
13 to 26 fl. oz. of product/acre |
|
|
Chloropyrifos plus zeta-cypermethrin (Stallion) |
5.0 to 11.75 fl. oz./acre |
|
|
Deltamethrin (Decis 1.5) |
0.018 to 0.022 lbs. a.i./acre (1.5 to 1.9 fl. oz.) |
|
|
Esfenvalerate (Adjourn) |
0.03 to 0.05 lbs. a.i./acre (5.8 to 9.6 fl. oz.) |
|
|
Gamma-cyhalothrin* (Proaxis) |
0.0075 to 0.0125 lbs. a.i./acre (1.92 to 3.20 fl. oz./acre) |
|
|
Imidacloprid (Alias 4F, Sherpa) |
|
|
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Imidacloprid plus cyfluthrin (Leverage 2.7) |
2.8 fl. oz./acre |
|
|
Lambda-cyhalothrin (Warrior w/ Zeon Technology) |
0.015 to 0.025 lbs. a.i./acre |
|
|
Lambda-cyhalothrin plus thiamethoxam (Endigo ZC) |
3.5 to 4.0 fl. oz./acre |
|
|
Lambda-cyhalothrin chlorantraniliprole (Besiege) |
5.0 to 8.0 fl. oz./acre |
|
|
Permethrin (Pounce 3.2 E) |
See label (Agrisolutions), 0.1 to 0.2 lbs. a.i./acre (4 to 8 fl. oz.) |
|
|
Zeta-cypermethrin (Mustang MAX) |
0.0175 to 0.025 lbs. a.i./acre (2.8 to 4.0 fl. oz.) |
|
|
Zeta-cypermethrin plus bifenthrin (Hero) |
4.0 to 10.3 fl. oz. of product/acre |