Sweet Corn Report, September 9th, 2014

Hudson Valley: The sweet corn lepidopteran complex of insects captured in New Paltz and Warwick traps this week show European corn borer (ECB) adult captures dramaticly decrease, low Corn Ear Worm (CEW) and increasing Fall Army Worm (FAW) adult trap captures. Generally, fewer insects were captured throughout the season in Warwick sweet corn fields. CEW captures in the Hudson Valley (New Paltz) are averaging 0.3 per day, requiring growers to be on a 6-day schedule; Fall armyworm (FAW) adult captures have seen a dramatic increase in the Hudson Valley with traps at 3.9 per day. The newly invasive Western Bean Cutworm (WBC) adult numbers continue declining.

Western bean cutworm, Striacosta albicosta, (WBC) a newly invasive sweet corn pest from the Western US, has been captured in both Warwick and New Paltz through much of the season with traps now showing no captures for the past two weeks. To date, no treatment is required for this insect this season. Highest captures occurred in New Paltz, totaling 6 per season. Cumulative trap catches of 100 moths would signal intensified scouting in fields nearing silk, HOWEVER, we have not seen trap captures of that volume in our trap sites. Threshold set in Ohio for fresh market sweet corn is 1%.

Western NY: Marion Zuefle reports that the second flight of European corn borer continues to decline over the past three weeks, with only 8 of 16 WNY trap sites reporting ECB populations requiring a programed spray interval (see chart below). Fall armyworm (FAW) numbers have increased dramatically with one site, Pavilion, catching a total of 220 moths. Three sites reported Western bean cutworm (WBC), but overall numbers continue to decline.

Eastern Long Island: Report from 8/25 E. LI. has very high FAW populations of 2.4-4.6 adults per day using green bucket traps. Highest CEW are at 5.3 per day with Riverhead on a 4-day schedule.

Across the region: CEW increasing in PA. Highest captures of CEW are in west central PA with daily trap captures at 39.4 at Holidaysburg, Blair County and nearer to Hudson Valley, 12.3 per day in Lehigh County, Germansville, PA. Scouting should be ongoing in fields that are in the whorl and silk stage for the presence of all three major insect pests. A five – six day spray interval is recommended when the weekly trap catch of CEW’s is less than seven adults per trap.