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Insecticide options for resistant soybean aphid

Soybean aphid has developed resistance to pyrethroid (Group 3A) insecticides. Currently, any populations of soybean aphid should be considered potentially resistant to pyrethroids. Insecticide rotations are an important part of insecticide resistance management and may help reduce the chances of further development of insecticide resistance in this pest.

Rotate insecticide groups

Table 1 summarizes some suggested rotations of insecticide groups for management of pyrethroid-resistant soybean aphids. Whether an insecticide seed treatment was used (see first column) will affect the suggested insecticide groups available for use for the first foliar application (see second column) against soybean aphid. Some considerations about these different insecticide groups are given in the fourth column. The insecticide groups suggested for a second foliar application (see third column), depend on what insecticide group was used for the first foliar application.

Table 2 provides a summary of different insecticides available for soybean aphid management.

Table 1. Pesticides labeled for control of soybean aphid on soybean. Note that chlorpyrifos is no longer available for food and feed crop use.

Seed treatment Initial foliar treatmentb Re-treatment optionsc Risks associated with initial foliar treatment option
4A (neonicotinoid)
4A 1A (methomyl) 3A+4A mixe, 4C, 4D, 9D High mammalian (human) toxicity; potential pollinator health concerns
4A 3A+1B mix (several)e 4C, 4D, 9D Continues selection for further Group 3A resistance in aphids; fewer retreat options; water quality concerns; potential pollinator health concerns
4A 4C (Transform)b,c 1A, 1Bd, 3A+1B mixe, 9D Preserve beneficials, but narrow control spectrum (sucking insects); potential pollinator health concerns
4A 4D (Sivanto)b,c 1A, 1Bd, 3A+1B mixe, 9D Preserve beneficials, but narrow control spectrum (sucking insects)
4A 9D (Sefina) 1A, 1Bd, 3A+1B mixe, 3A+4A mixe, 4C, 4D Preserve beneficials, but narrow control spectrum (sucking insects)
No insecticide
No insecticide 1A (methomyl) 3A+4A mixe, 4C, 4D, 9D High mammalian (human) toxicity; potential pollinator health concerns
No insecticide 3A+1B mix (several)e 4C, 4D, 9D Continues selection for further Group 3A resistance in aphids; fewer retreat options; water quality concerns; potential pollinator health concerns
No insecticide 3A+4A mix (several)e 1A, 1Bd, 9D Continues selection for further Group 3A resistance in aphids; fewer retreat options; potential pollinator health concerns
No insecticide 4C (Transform) 1A, 1Bd, 3A+1B mixe, 9D Preserve beneficials, but narrow control spectrum (sucking insects); potential pollinator health concerns
No insecticide 4D (Sivanto) 1A, 1Bd, 3A+1B mixe, 9D Preserve beneficials, but narrow control spectrum (sucking insects)
No insecticide 9D (Sefina) 1A, 1Bd, 3A+1B mixe, 3A+4A mixe, 4C, 4D Preserve beneficials, but narrow control spectrum (sucking insects)

aInsecticide groups: 1A=Carbamates, 1B=Organophosphates, 3A=Pyrethroids, 4A=Neonicotinoids, 4C=Sulfoxamines, 4D=Butenoloides, 9D=Pyropenes.
Aphids resistant to Group 3A are widespread; all populations should be considered potentially resistant to Group 3A.
Migration of aphids previously exposed to insecticides reduces ability to maintain effective insecticide rotation, particularly later in the season.

bIf a neonicotinoid seed treatment was applied, avoid any Group 4A insecticides in initial foliar application. It may be prudent to avoid 4C and 4D, as well

cAlthough there are no documented cases of cross-resistance among Group 4 insecticide subgroups (4A, 4C, 4D), it is suggested to avoid using them in sequential applications including seed treatments. 

dOther labeled group 1B insecticides (dimethoate) are not recommended as a stand-alone insecticide, due to inconsistent aphid control.

eInsecticide mixtures are usually not desirable from an insecticide resistance management standpoint, but may be unavoidable with limited effective insecticide groups. Mixes with reduced rates of either insecticide may increase risk for development of insecticide resistance.

Table 2. Insecticide groups, active ingredients and example products for management of soybean aphid.

Group Common name Individual A.I.s Formulated mixtures
1A=Carbamates methomyl Lannate
1B=Organophosphates acephate Acephate
1B dimethoate Dimethoate
3A=Pyrethroids alpha-cypermethrin Fastac Leverage
3A beta-cyflufthrin Baythroid
3A bifenthrin Bifenture, Brigade, Discipline, Fanfare, Tundra, Sniper Justice, Brigadier, Swagger, Skyraider, Hero, Steed, Triple Crown
3A cyfluthrin Tombstone
3A deltamethrin Batallion, Delta Gold
3A esfenvalerate Adjourn, Asana XL
3A gamma-cyhalothrin Declare, Proaxis
3A lambda-cyhalothrin Grizzly Z, Lambda-Cy, LambdaStar, Lamcap, Province, Silencer VC, Taiga Z, Warrior II Besiege, Double Take, Endigo, Seeker
3A permethrin Arctic
3A zeta-cypermethrin Mustang Maxx, Respect Hero, Steed, Triple Crown
4A=Neonicotinoids acetamiprid Justice
4A clothianadin Belay
4A imadacloprid Admire Pro, Alias, Nuprid, Sherpa, Prey, Wrangler Brigadier, Leverage, Skyraider, Swagger, Triple Crown
4A thiamethoxam Endigo
4C=Sulfoxamines sulfoxaflor Closer, Transform
4D=Butenoloides flupyradifurone Sivanto
9D=Pyropenes afidopyropen Sefina

Scout for soybean aphids

Decisions to apply foliar insecticides for soybean aphid should be based on regular scouting of soybean fields. Through the R5 soybean growth stage, application of foliar insecticides is justified when aphid populations reach the economic threshold of an average of 250 aphids per plant (with 80% of plants infested with aphids and aphid populations increasing).

Continued scouting of soybean fields after insecticide application is necessary to determine if the insecticide application was effective and to determine if another insecticide application is necessary. Retreatment of a field may be necessary due factors such as poor performance of the insecticide or reinfestation of the field by winged aphids coming from elsewhere.

For more information, see Scouting for soybean aphid.

Read and follow the pesticide label.

Products are mentioned for illustrative purposes only. Their inclusion does not mean endorsement and their absence does not imply disapproval.

Robert Koch, Extension entomologist and Bruce Potter, Extension IPM specialist

Reviewed in 2022

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