Thirty-two of 38 sites reported this week. European corn borer (ECB)-E was caught at 3 sites and ECB-Z was caught at 7 sites all in the single digits. Corn earworm was caught at 11 sites with 5 sites high enough to be on a 4, 5, or 6 day spray schedule (see table below). No fall armyworm (FAW) caught this week but 2 sites reported the first catch of Western bean cutworm (WBC), Florida and Penn Yan.
Even though ECB trap catch numbers remain low, feeding damage has been observed in the field. If corn is in the tassel emergence stage, scout the tassel for any signs of larvae or frass (Scouting and Threshold Information). The threshold for tassel emergence stage corn is 15%.
If the corn field is silking, scout for egg masses and larvae within the ear zone. The threshold for silking corn now drops to 5% infested plants. The ear zone is the area between the two leaves above the top ear and one leaf below the bottom ear. ECB egg masses are usually located on the underside of the leaf along the midrib. The egg mass consists of 5-50 flattened eggs that overlap like fish scales (see photo below). Be sure to check the ear as well, as eggs are sometimes laid on the husk and flag leaves. Larvae are often found between the ear and stalk, or sometimes in the top of the silks. Tease the silks apart to look for feeding damage and larvae without causing too much “scouting damage”. When scouting, be sure to select scouting locations throughout the entire field to get a good estimate of infestation levels. If you would like to download a scouting form to use in the field please go to Sweet corn scouting form (pdf).
Eggs take approximately 100 base 50 degree days to hatch. Egg masses will change from white to cream to black as they age. When they appear black they are in the “black head” stage and will most likely hatch with 24 hours (see photo).
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- ECB egg mass – white in color (photo University of Nebraska).
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- ECB egg mass “black head” stage (photo University of Nebraska).
Hi Farmers of NYS, do you think growing tree nuts (chestnuts, hazelnuts, walnuts, etc.) is a nutty idea, or worth considering?
Please take a few minutes to fill out this brief survey for a Cornell PhD project. Thanks!
Additional survey link: http://bit.ly/NYSNuts
| Location | ECB-E | ECB-Z | CEW | FAW | WBC | DD to Date |
|
| Accord (Ulster Co.) | 0 | 0 | 0 | NA | 0 | 1112.3 | |
| Amsterdam (Fulton Co.) | 0 | 0 | 0 | 0 | 0 | 1004.3 | |
| Athens (Greene Co.) | NA | NA | NA | NA | NA | 1161.1 | |
| Avon (Livingston Co.) | 0 | 0 | 1 | 0 | 0 | 1063.9 | |
| Baldwinsville (Onondaga Co.) | 0 | 1 | 0 | 0 | 0 | 1104.7 | |
| Batavia (Genesee Co.) | 0 | 0 | 0 | 0 | 0 | 1103.2 | |
| Bellona (Yates Co.) | 0 | 0 | 0 | 0 | 0 | 1129.9 | |
| Eagle Bridge (Washington Co.) | 0 | 0 | 0 | 0 | 0 | 934.5 | |
| Eden (Erie Co.) | 0 | 0 | 3 | 0 | 0 | 1123.8 | |
| Farmington (Ontario Co.) | 1 | 0 | 0 | 0 | 0 | 1073.2 | |
| Feura Bush (Albany Co.) | 0 | 2 | 0 | 0 | 0 | 1003.1 | |
| Florida (Orange Co.) | 0 | 4 | 4 | 0 | 1 | 1185.5 | |
| Geneva (Ontario Co.) | NA | NA | NA | NA | NA | 1098.1 | |
| Greenwich (Washington Co.) | 0 | 0 | 0 | 0 | 0 | 934.5 | |
| Hamlin (Monroe Co.) | NA | NA | NA | NA | NA | 1012.9 | |
| Hurley (Ulster Co.) | 0 | 0 | 1 | 0 | 0 | 1134.6 | |
| Kennedy (Chautauqua Co.) | 0 | 0 | 0 | 0 | 0 | 1011.0 | |
| Kinderhook (Columbia Co.) | 0 | 2 | 4 | 0 | 0 | 1103.6 | |
| King Ferry (Cayuga Co.) | 1 | 0 | 0 | 0 | 0 | 1106.1 | |
| Kirkville (Madison Co.) | 0 | 0 | 2 | 0 | 0 | 1070.5 | |
| New Paltz (Ulster Co.) | 1 | 1 | 9 | NA | 0 | 1134.6 | |
| Oswego (Oswego Co.) | 0 | 0 | 0 | 0 | 0 | 1034.3 | |
| Owego (Tioga Co.) | 0 | 0 | 0 | 0 | 0 | 941.0 | |
| Pavilion (Genesee Co.) | 0 | 0 | 1 | 0 | 0 | 925.0 | |
| Penn Yan (Yates Co.) | 0 | 5 | 0 | 0 | 1 | 1132.5 | |
| Peru (Clinton Co.) | 0 | 0 | 0 | 0 | 0 | 950.3 | |
| Plattsburgh (Clinton Co.) | NA | NA | NA | NA | NA | 919.0 | |
| Plessis (Jefferson Co.) | 0 | 0 | 0 | 0 | 0 | 963.0 | |
| Preble (Cortland Co.) | 0 | 0 | 0 | 0 | 0 | 1076.4 | |
| Ransomville (Niagara Co.) | 0 | 0 | 0 | 0 | 0 | 1114.0 | |
| Schaghticoke (Rensselear Co.) | NA | NA | NA | NA | NA | 1111.3 | |
| Seneca Castle (Ontario Co.) | 0 | NA | 1 | 0 | 0 | 1004.3 | |
| Sharon Springs (Schoharie Co.) | 0 | 0 | 0 | 0 | 0 | 1074.4 | |
| Sherwood (Cayuga Co.) | NA | NA | NA | NA | NA | 1106.1 | |
| South Colton (St. Lawrence Co.) | 0 | 0 | 0 | 0 | 0 | 799.0 | |
| Stone Ridge (Ulster Co.) | 0 | 0 | 1 | NA | NA | 1134.6 | |
| Tivoli (Dutchess Co.) | 0 | 2 | 1 | NA | NA | 1174.2 | |
| Williamson (Wayne Co.) | 0 | 0 | 0 | 0 | 0 | 990.2 | |
| 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 6.26.18 – 7.3.18 |
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