You are here

Scouting a must for 2011 soybean aphids

Results of fall scouting of
soybean aphid indicate that soybean growers may face some level of soybean
aphid populations this summer.

“We expect Ohio to continue
its two-year cycle of very few if any aphids being found followed by low to
moderate to even high populations somewhere in the state,” said Ohio State
University Extension entomologist Ron Hammond with the Ohio Agricultural
Research and Development Center.

Hammond and his colleagues
scouted for eggs on buckthorn, the pest’s overwintering host, and found some
eggs, although not as many as anticipated. However, given the observations
recorded of aphids on buckthorn in other Midwest states, entomologist believe
Ohio will likely see more aphids next year than in 2010.

“It is impossible to predict
which regions of Ohio, if any, will experience outbreak conditions,” said
Hammond, explaining that factors ranging from the weather to natural predators
all play a role in the severity of aphid populations. “At this time, growers
should just be aware that scouting for aphids will probably be more important
next summer during July and early August.”

The soybean aphid, first
discovered in Ohio in 2001, is a sapsucker whose voracious appetite can greatly
damage untreated soybean fields. It also has been known to transmit a host of
viruses, including soybean mosaic virus, soybean dwarf virus, and alfalfa
mosaic virus not only in soybean but also in a number of vegetable crops.

Soybean aphid populations
this past summer were practically nonexistent, although entomologists did see a
build-up of aphids on late-maturing soybeans. However, the late aphid build-up
was expected and is a contributing factor to finding eggs on buckthorn this

For growers, the best way to
manage the soybean aphid is to educate themselves on the insect, know when to
scout, and to carefully time foliar insecticide applications if treatments are
warranted. The economic threshold of aphids is 250 insects per plant with a
rising population.

"We continue to
recommend taking an Integrated Pest Management (IPM) approach to aphid
management. While seed treatments will control early season aphid populations,
they will not have any impact in mid-summer when aphids arrive in large
numbers," said Hammond. "We will recommend scouting soybeans from
early July through August, and using the threshold with a rising population
density to determine the need for treatment."

By Candace Pollack, Ohio State
University Extension

Read more about