Rutgers Cooperative Extension
Sweet Corn
European corn borer (ECB) moth catches are increasing slightly in parts of the state. Overall numbers remain quite low, however. 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 08/03/22 are as follows:
| Centerton 1 | Farmingdale 1 | New Egypt 1 |
| Cinnaminson 1 | Georgetown 1 | Old Bridge 1 |
| Crosswicks 1 | Matawan 1 | Sergeantsville 1 |
| Downer 1 | Medford 1 | Springdale 1 |
Sweet Corn – Fall Armyworm
As of Wednesday (7/27) evening, significant fall armyworm (FAW) infestations were found in whorl stage sweet corn in Cape May County. These infestations were nearing 50% of plants infested, and are an indication that all sweet corn growers in southern NJ should be checking fields regularly for signs of FAW feeding. This pest often hits earliest and hardest in coastal areas, and new infestations have been detected up the coast to Monmouth County. Northern infestations have been much lower, and very recent.
Look for extensive foliar feeding in sweet corn ranging from seedling to pre-tassel stage. FAW create large volumes of droppings that often cover larvae while feeding in the whorl. Untreated infestations can result in severely stunted plants. Consider treating when FAW feeding alone, or in combination with European corn borer exceeds 12%. Insecticides in the IRAC 28 class (diamides) and IRAC 5 class (spinosyns) work well against FAW.
Sweet Corn
European corn borer (ECB) moth catches continue to be extremely low around the state, although there has been some increase in adults in southern traps. 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 07/27/22 are as follows:
| Allentown 1 | Jones Island 1 | Oldwick 1 |
| Eldora 1 | Medford 1 | Tabernacle 1 |
| Elm 1 | Milltown 1 | |
| Georgetown 1 | New Egypt 1 |
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 07/20/22 are as follows:
| Allentown 1 | Old Bridge 1 |
| Dayton 1 | Sergeantsville 1 |
| Hillsborough 1 | South Branch 1 |
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 07/13/22 are as follows:
| Hillsborough 1 | Port Murray 1 |
| Milford 1 | Sergeantsville 1 |
| Milltown 1 | South Branch 1 |
| Oldwick 1 |
Sweet Corn
Note: No trap data from the southern counties is available this week, so maps will not appear in this edition.
European corn borer (ECB) moths remain a sporadic, low component of blacklight trap catches. Feeding in pre-tassel stage is still present in some areas, but is now less common. ECB injury over the threshold of 12% of plants infested, while still around, has been declining.
Growers should still examine plantings in whorl or pre-tassel stages for signs of ECB injury. 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. [Read more…]
