Nineteen sites reporting this week. Four sites reporting European corn borer (ECB)-E with one as high as 12 moths. ECB-Z was also caught at 4 sites this week. Corn earworm (CEW) was caught at four sites with Preble high enough to require a 6 day spray interval. Fall armyworm (FAW) numbers are beginning to pick up with five sites reporting and with Pavilion and Penn Yan having 13 and 20 moth respectively. Western bean cutworm (WBC) was caught at 7 sites this week.
Fall army worm numbers are up this week. When scouting sweet corn look for FAW egg masses on the leaves. Egg masses consist of 50-150 eggs and can be distinguished from ECB by the fine hairs covering the egg mass. Feeding damage is also very different from ECB. FAW will cause ragged feeding damage on leaves with large amounts of frass below the feeding site. The larva has a distinct inverted ‘Y’ on the front of the head.
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- Fall armyworm egg mass.
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- Fall armyworm damage
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- Fall armyworm larva, note the inverted ‘Y’ om head capsule.
WBC emergence is forecast to be at 25% when 1319 degree days (base 50°F) have accumulated beginning on May 1st (see table below). The degree day accumulation (May 1st, base 50°F) for sweet corn trap network sites ranges from 860-1193 with an average of 1064. Degree day forecasts pertain only to local populations, the migrant population is much more unpredictable.
Percent WBC moth emergence, data from
University of Nebraska
| Location | ECB-E | ECB-Z | CEW | FAW | WBC | Total WBC to date |
DD to date |
| Avoca (Steuben Co.) | 0 | 0 | 0 | 0 | 0 | 0 | 973.0 |
| Avon (Livingston Co.) | 0 | 0 | 0 | 2 | 0 | 1 | 1167.9 |
| Baldwinsville (Onondaga Co.) | 0 | 0 | 1 | 0 | 1 | 2 | 1157.5 |
| Batavia (Genesee Co.) | 12 | 0 | 0 | 0 | 1 | 2 | 860.1 |
| Belfast (Allegany Co.) | NA | NA | NA | NA | NA | 0 | 1001.3 |
| Bellona (Yates Co.) | NA | NA | NA | NA | NA | NA | 1193.0 |
| Eden (Erie Co.) | 0 | 0 | 0 | 0 | 2 | 3 | 1039.7 |
| Farmington (Ontario Co.) | 1 | 0 | 0 | 0 | 0 | 0 | 1063.4 |
| Hamlin (Monroe Co.) | 2 | 1 | 0 | 0 | 0 | 0 | 1036.1 |
| Kennedy (Chautauqua Co.) | 0 | 0 | 0 | 1 | 0 | 2 | 917.7 |
| King Ferry (Cayuga Co.) | 0 | 0 | 0 | 0 | 0 | 0 | 1138.4 |
| Kirkville (Madison Co.) | NA | NA | NA | NA | NA | NA | 1184.7 |
| LeRoy (Genesee Co.) | 2 | 1 | 1 | 0 | 0 | 0 | 1022.8 |
| Lockport (Niagra Co.) | 0 | 0 | 0 | 0 | 0 | 1 | 1060.0 |
| Oswego (Oswego Co.) | 0 | 0 | 0 | 0 | 2 | 2 | 1048.8 |
| Owego (Tioga Co.) | NA | NA | NA | NA | NA | 0 | 1012.8 |
| Pavilion (Genesee Co.) | 0 | 0 | 1 | 13 | 2 | 2 | 1022.8 |
| Penn Yan (Yates Co.) | 0 | 3 | 0 | 20 | 1 | 1 | 1152.5 |
| Plessis (Jefferson Co.) | 0 | 1 | 0 | 1 | 1 | 1 | 1024.7 |
| Preble (Cortland Co.) | 0 | 0 | 2 | 0 | 0 | 1 | 1115.5 |
| Seneca Castle (Ontario Co.) | 0 | 0 | 0 | 0 | 0 | 0 | 1086.6 |
| Sherwood (Cayuga Co.) | NA | NA | NA | NA | NA | NA | 1138.4 |
| Spencerport (Monroe Co.) | 0 | 0 | 0 | 0 | 0 | 0 | 1167.9 |
| Waterport (Orleans Co.) | 0 | 0 | 0 | 0 | 0 | 0 | 1036.1 |
| Williamson (Wayne Co.) | NA | NA | NA | NA | NA | 0 | 997.9 |
| ECB – European Corn Borer CEW – Corn Earworm FAW – Fall Armyworm WBC – Western Bean Cutworm NA – not available DD – Degree Day (modified base 50F) accumulation |
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| trap catches for the week of 7.7.15 – 7.14.15 |
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