Hudson Valley: The sweet corn lepidopteran complex of insects were captured in New Paltz and Warwick traps this week. Generally, fewer insects were captured throughout the season in Warwick sweet corn fields. CEW captures in the Hudson Valley (New Paltz) are averaging 0.4 per day, requiring growers to be on a 6-day schedule; second generation European corn borer (ECB) adult captures are declining, Fall armyworm (FAW) adult captures has seen a dramatic increase in the Hudson Valley with traps at 3.3 per day, and the newly invasive Western Bean Cutworm (WBC) adult has remained quite low for the season, with numbers declining sharply last week.
We began captures of the western bean cutworm, Striacosta albicosta, (WBC) in both Warwick and New Paltz in late July. To date no treatment is required for this insect this season. Scouting for eggs should continue in the upper 4 leaves of late whorl and early tassel-emergence as these fields during this stage of development are most at risk. Egg masses can be found even if no trap captures are observed. Cumulative trap catches of 100 moths should 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%. Upon hatch, larvae will spend a few days feeding on the tassel before moving down to the ear. Most insecticide sprays used to control ECB will also control WBC.
Western NY: Marion Zuefle reports that the second flight of European corn borer has declined over the past two weeks, with only five WNY trap sites reporting European corn borer-E (ECB-E) and seven sites with ECB-Z. Corn earworm (CEW) was reported from 6 sites with three sites requiring a 5 or 6 day spray interval (see chart below). Fall armyworm (FAW) numbers continue to increase with one site, Pavilion, catching a total of 72 moths. Several reports of FAW damage and have seen feeding damage in several of the fieldsTen sites reported Western bean cutworm (WBC), but overall numbers continue to decrease.
Eastern Long Island: E. LI. has very high FAW populations of 18.9 adults per day in Mattituck using green bucket traps. CEW are below threshold averaging between 1.7 and 8.0 per day with Mattituck on a 4-day schedule.
Across the region: Highest captures of CEW are in west central PA with daily trap captures at 11.4 per day in Blair County, Holidaysburg, PA.
