Working with researchers is always interesting and rewarding, but can sometimes be frustrating. As in past years, we are cooperating with several of our top Ohio State University Extension specialists, helping them to obtain data necessary for their various studies.

This week we trekked through six wheat fields in six different townships to assess the levels of head scab. Dr. Pierce Paul, Ohio State University Extension plant pathologist, continues to work with fellow researchers gathering information to contribute to the national database for forecasting of Fusarium head blight (head scab). A graduate student worked with us to check fields 18 to 21 days after flowering.

Symptoms of head scab include spikelets of the head turning straw colored, glume edges showing pink spore masses and wheat kernels that are shriveled white to pink in color. Our observations were marked on a data sheet along with location of the field, variety and planting date. A few scabby heads were gathered for further assessment at the laboratories of the Ohio Agriculture Research and Development Center.

Where wet warm weather was persistent during the flowering period, we anticipated finding a higher incidence of the disease. Final assessment information will be summarized and used to improve the national scab forecasting model.

We are also working with OSU Extension Entomologists Andy Michel and Ron Hammond on tracking the western bean cutworm (WBCW) historically found in the western Corn Belt, where it was a common pest of dry beans and a sporadic pest of corn.

Since 2000, this pest has continued to rapidly spread eastward, reaching Ohio in 2006. The easiest way to monitor the presence of this pest is trapping of the adult moths. In 2006, 3 adults were caught, 6 in 2007, 150 in 2008, and over 500 in 2009. Most moths have been caught in the extreme northwest or west central portion of Ohio. Locally, we trapped one in 2006, 2 in 2007 and none the past two years.

The adults emerge in late June – early July, are mostly dark brown and black, with three characteristic markings that distinguish them from other moths: (1) a white stripe on the top edge of the forewing, (2) a light brown-tan colored dot, and (3) a comma or crescent-shaped mark behind the dot. Mid-flight of the adults usually occurs in mid-July, with adult flight ending by mid to late August.

Females lay eggs on the uppermost portion of the flag leaf, in unevenly distributed clusters of 5–200, but averaging about 50 per cluster, and hatch within 5–7 days. Eggs first appear white, then tan and then a dark royal purple.

Once eggs turn purple, hatching should occur within 24 hours.
Larvae begin to feed on the flag leaf and unemerged tassel, then move to the ear, while feeding on corn pollen, leaf tissue, silks and eventually the ear itself.

We are monitoring corn fields with simple pheromone traps. Four windows from an empty gallon milk jug are cut, and the jug is tied to a post at least four feet high. A bent paper clip is used to attach a pheromone lure to the inside lid of the milk jug and the cap is replaced to keep the lure in place. The bottom of the jug is filled with a 4:1; water/antifreeze solution, with a drop of dish soap added. One trap was placed on the edge of each cornfield. Traps will be inspected at least weekly.

WBCW economic damage has been reported in Indiana and Michigan, not yet in Ohio. For now, scouting remains the growers’ best tool for managing WBCW.

Readers with questions or comments for Roger Bender may write to him in care of this publication.