CONTROL RESISTANT APHID POPULATIONS
AND PROTECT SOYBEAN YIELD POTENTIAL
The
well-documented
development
of
resistant
insect pest populations dates back to the early
1900s. Farmers in Iowa and Minnesota can attest
to
th e
p ro p e n s it y
fo r
res is ta n ce
d eve l o p m e nt
a f te r
a t te m p t i n g
to
c o n t ro l
t h r e s h o l d - l eve l
populations
of
soybean
aphids
between
2000
and 2008 with pyrethroids.
“One season, heavy aphid populations were reported as far south
as Missouri,” said Dennis Holland, market development specialist
with Corteva Agriscience. “That was really unheard of at the time, but
cooler summer temperatures can accelerate aphid populations in any
given year.”
Aphids can cause up to 50% yield loss, especially when
infestations reach the commonly advocated threshold of 250
aphids per plant between early growth stages (pod fill) R1 to
R5.1
“Several growers I’ve spoken with who made
applications with a single mode-of-action pyrethroid product
scouted those fields three to five days later and still found aphid
populations meeting threshold,” Holland said. “Thorough scouting is
keytoverifytheeffectiveness of any insecticide application, even
late into the plant’s reproductive growth stages.”

is more readily available and preferred. This is especially
common during heavy infestations.
North Dakota State University aphid research confirms a yield
increase with Ridgeback insecticide.2
“It’s also tank-mix-friendly with fungicides, which could reduce
trips across the field when treating for aphids and foliar
diseases.” Holland said. “Don’t forget the importance of good
coverage. Even though 10 gallons per acre is recommended for a
ground rig, I’m not opposed to using 15 to 20 gallons.”
Some weather forecasters expect the La Niña weather
pattern to weaken and shift toward El Niño later this
growing season, possibly bringing weather that swings
between cooler and warmer temperatures.
“If this shift occurs, maintain a vigilant scouting
regimen and be ready to call your local retailer
to
discuss
all
the
benefits
and
added
value
Ridgeback
insecticide
offers
through
its
unique
mode of action,” Holland concludes.

GO WITH MULTIPLE MOA, FLEXIBILITY
Aphid populations can sometimes increase after foliar
applications
because
resistant
aphids
survive
and
reproduce. This exacerbates the cycle of resistance and increases
the need for a more effective insecticide.
“This is where Ridgeback insecticide can be a great
product solution — in regions where soybean farmers battle
infestations of aphids,” Holland said. “Bringing an additional
mode of action, sulfoxaflor (Group 4C) is field-tested and proven to
control soybean aphids, as well as Japanese beetles, spider mites
and other pests, while also strengthening resistance management
stewardship.”
Ridgeback® insecticide with Isoclast® active works by
contact and ingestion. It has excellent translaminar movement to
target aphids under soybean leaves, where tender new growth

1

Legend Seeds. 2025. Spraying for Aphids in Soybeans: What You Need to Know. https://legendseeds.net/news-and-info/agronomy-library/spraying-aphids-soybeans

2

Oxford Academic. 2026. Efficacy of insecticides against soybean aphid, 2024. https://academic.oup.com/amt/article/51/1/tsag024/8559683

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Corteva.com/TrustedControl

™ ® Trademarks of Corteva Agriscience and its affiliated companies. Ridgeback® is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale
or use in your state. Isoclast® is a registered active ingredient. Always read and follow label directions. ©2026 Corteva. 037917 BR (03/26) CAAG26INSC0414