Rutgers Cooperative Extension
Sweet Corn
European corn borer (ECB) moth catches continue to be extremely low around the state. We are in between adult generations at this time. ECB population maps will resume if second flight catches rise to high enough numbers.
The highest nightly trap catches of ECB for the week ending 07/14/21 are as follows:
| Crosswicks 1 |
| Elm 1 |
NOTE: Cucurbit downy mildew (CDM) was detected on cucumbers at the Snyder Research and Extension Farm in Hunterdon County on Wednesday 07/07/21. No other cucurbit crops exhibited signs of infection. Growers should assume that CDM races that infect cucumber and possibly muskmelons are now active in ALL parts of the state. See the Pumpkin and Winter Squash section below for more information.
Sweet Corn
European corn borer (ECB) moth catches continue to be extremely low around the state. The few remaining infestations are in pre-tassel stage sweet corn. Whorl is largely un-infested with ECB at this time. ECB population maps will resume if second flight catches rise to high enough numbers.
The highest nightly trap catches of ECB for the week ending 07/07/21 are as follows:
| Blairstown 1 |
| Downer 1 |
| East Vineland 1 |
| Milford 1 |
Sweet Corn
European corn borer (ECB) moth catches have dropped to nearly nothing around the state. Remaining infestations are in pre-tassel stage sweet corn. Whorl is largely un-infested with ECB at this time. ECB population maps will resume if second flight catches rise to high enough numbers.
The highest nightly trap catches of ECB for the week ending 6/30/21 are as follows:
| Asbury 1 |
| Downer 1 |
| Milltown 1 |
| Oldwick 1 |
Sweet Corn
European corn borer (ECB) moth catches remain very low, and concentrated primarily in Gloucester County (see map below at right). Most active infestations now are in pre-tassel stage corn, with whorl corn largely free of feeding as egg laying has declined. Feeding in scouted pre-tassel stage sweet corn ranges to above 30% in Hunterdon County.
Look for the characteristic “shot-hole” type of feeding (photo below at right) and consider treating when infested plants exceed 12% in a 50 plant sample. As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left). It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time. This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.
Useful insecticides for this particular application include synthetic 
pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen. Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn. Control with these materials is very inconsistent.
The highest nightly trap catches of ECB for the week ending 6/23/21 are as follows:
| Downer 2 | New Egypt 1 |
| Cinnaminson 1 | Old Bridge 1 |
| Medford 1 | South Branch 1 |
Sweet Corn
Low numbers of European corn borer (ECB) moths continue to be captured, with little change from the previous week. We anticipate that this initial flight is nearing its’ end. The highest adult activity is currently Gloucester County (see map below at right). Whorl corn is the primary target for egg laying, and injury as high as 40% of plants infested has been found in Hunterdon County this week. This high feeding percentage is an outlier relative to what scouts are typically finding this season. Most infestations are in the single-to- mid teens in terms of plants infested. It is typical for feeding percentages to rise as the moth catch declines. We expect feeding to increase for the next 1-2 weeks before peaking.
Look for the characteristic “shot-hole” type of feeding (photo below at right) and consider treating when infested plants exceed 12% in a 50 plant sample. As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left). It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time. This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.
Useful insecticides for this particular application include synthetic pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen. Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn. Control with these materials is very inconsistent.
The highest nightly trap catches of ECB for the week ending 6/16/21 are as follows:
| Downer 3 | Dayton 1 | Lawrenceville 1 |
| Asbury 1 | Denville 1 | Medford 1 |
| Centerton 1 | Hillsborough 1 | Sergeantsville 1 |
| Chester 1 | Jones Island 1 | Tabernacle 1 |
2021 Vegetable IPM Program Personnel
Kris Holmstrom and Joe Ingerson-Mahar would like to acknowledge the IPM Field Technicians for this season:
Rhea Bolar
Claire Chapeau
Jeff Kane
Jake Newcombe
Gabriel Torres
Without the assistance of these individuals, much of the information presented in this publication would be unobtainable. We are grateful for all their help and hard work.
Sweet Corn
Low numbers of European corn borer (ECB) moths continue to be captured in parts of the state. Hot weather over the past week has not increased catches, indicating that this initial flight may be nearing its’ end. The highest adult activity is currently Gloucester and western Burlington counties (see map at right). Whorl corn is the primary target for egg laying, and injury as high as 18% of plants infested has been found in Hunterdon County this week. It is typical for feeding percentages to rise as the moth catch declines. We expect feeding to increase for the next 1-2 weeks before peaking.
Look for the characteristic “shot-hole” type of feeding (photo below at right) and consider treating when infested plants exceed 12% in a 50 plant sample. As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left). It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time. This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.
Useful insecticides for this particular application include synthetic pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen. Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn. Control with these materials is very inconsistent.
The highest nightly trap catches of ECB for the week ending 6/09/21 are as follows:
| Cinnaminson 2 | Centerton 1 | Green Creek 1 |
| Downer 2 | Crosswicks 1 | Milford 1 |
| Asbury 1 | East Vineland 1 | Oldwick 1 |
| Califon 1 | Eldora 1 | Sergeantsville 1 |
