AgEBB-MU CAFNR Extension

David Burton
Civic Communications Specialist
2400 S. Scenic Ave.
Springfield, MO 65807

August 11, 2017

Field Crop Scouting Report
Scout for Sugarcane Aphid in Milo

LAMAR, Mo. — Jill Scheidt, agronomy specialist with University of Missouri Extension, scouted fields north and south of Avilla for the July 26 crop scouting update.

Printed reports are sent out two weeks after the report to allow subscribers to phoned reports the full benefit of their subscriptions. Barton County MU Extension sponsors the field scouting report. For more information on the scouting report, or to learn how to receive the information earlier by telephone, contact the Barton County Extension Center at (417) 682-3579.


Corn ranged from silk to beginning dent stage.

"Very little pest damage was observed, very little corn earworm feeding and ear rot was present. Japanese beetles were not present and are not of concern once corn is finished pollinating," said Scheidt.

Scheidt gave tips to check how well corn pollinated. "Carefully strip husks without disturbing silks. Turn the ear horizontal and shake it; silks that remain attached have not pollinated and detached silks have pollinated kernels," said Scheidt.


Soybeans ranged from first trifoliate to beginning bloom stages.

"Defoliation pressure from foliage feeding insects was less than 5 percent," said Scheidt.

Threshold for any foliage-feeding insect in soybeans is 30% defoliation before bloom and 20% defoliation during or after bloom.

"No podworms were seen," said Scheidt. Threshold level for podworm in soybeans is one per foot of row or when 5% or more of pods are damaged.


Scheidt observed two sugarcane aphids in milo in the heading stage, but only on one plant.

"It was not close to threshold, scout weekly by looking on the underside of the leaf for pressure of sugarcane aphid," said Scheidt.

Threshold level for yellow sugarcane aphid in boot to head stage is 500 aphids per plant or when 2 dead leaves are present. Head to maturity stages have a threshold level of 750 aphids per plant or when 2-3 dead leaves are present.

Growth Stage specific thresholds for Missouri:


University of Missouri Extension programs focus on the high-priority needs of Missourians to improve lives, communities and economies by providing relevant, responsive and reliable educational solutions. Each county extension center, with oversight by locally elected and appointed citizens, is your local link to practical education on almost anything. More information on this topic is available online at

Source: Jill Scheidt, (417) 682-3579

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