Only nineteen sites reporting this week. Unfortunately, only one site from eastern NY was able to report this week. Of the nineteen sites, eight sites trapped European corn borer (ECB)-E with the high count of 97 coming from Hurley in Ulster County again. ECB-Z was trapped at six sites. Corn earworm (CEW) was trapped at seven sites, with six sites high enough to be on a 4, 5, or 6 day spray schedule (see chart below). Fall armyworm (FAW) was trapped at eight sites and Western Bean cutworm (WBC) was trapped at seventeen sites this week.

The average degree days for the trap sites is 1611 base 50 (starting May 1), so the majority of WBC moths should have emerged according to the University of Nebraska model. Looking at the graph below, overall WBC trap catches are down this week as compared to last week, but some individual sites are still showing high trap catches. Where CEW numbers are not high enough to determine the spray schedule, scout for ECB, FAW and WBC egg masses and larvae in late whorl and tassel-emergence stage fields.

Percent WBC moth emergence, data from
University of Nebraska

Average sweet corn trap catches for all reporting sites from 5.23.17 – 8.15.17

This week I am including trap catch data from WBC traps set up near dry bean fields.

Dry Bean Western Bean Cutworm Alert
 8.15.17
Marion Zuefle, NYS IPM Program
(Alert modified from Carol McNeil)
(Information and photos from T. Baute, OMAFRA)

Western bean cutworm (WBC) moths have reached the 100 cumulative moths/trap threshold at six of the 13 sites that we are monitoring this year. Peak flight occurred between August 1^st and 8^th  for most of the sites. All dry bean growers should begin scouting pods for WBC feeding about 10 days after peak flight regardless of cumulative trap catch, and should continue to scout for three weeks, especially if damage has been seen in recent years.

Check 10 random spots in a field, 5 plants per spot. Inspect all the pods on the plants looking for holes. Surface feeding can be caused by other insects. WBC will mine directly into the pod and will often feed on the seed inside. European corn borer will also feed inside the pod and would most likely still be present. If there is damage going directly into the pod and seed but no larva present, it is quite possibly WBC. During the day WBC larva are not actively feeding in the pod, instead they drop to the soil and will remain there until night. Fresh damage will be green, not brown. If damage is seen then the field should be sprayed once with a pyrethroid insecticide (Entrust in organic fields).

If you have questions contact Marion Zuefle at mez4@cornell.edu  or 315-787-2379.

This project is funded by the NYS Dry Bean Industry.

Location of WBC traps near Dry Beans 2017