Attention:  Please refer to this updated CEW pheromone map for the weekending 9/30/20.  We were able to procure some late data from traps in the southwestern portion of the state.  These indicate a significant influx of CEW moths on the recent storm system.  At this time, these migratory individuals appear to be limited to southwestern NJ (see CEW pheromone map at left).  The blacklight network is still indicating a 3-day silk spray schedule in the northern counties, while the pheromone network is at 5-6 day.  In the south, the pheromone map is now indicating a 3 day spray schedule.  Under cold night conditions, it is possible to adhere to a more relaxed schedule, but growers should tighten up by a day if we return to warmer nights.   The number of pheromone traps deployed is much lower, resulting in much broader color bands on the map.    Additionally, several of the northern pheromone trap sites no longer have silking corn nearby.  This influences the catch, resulting in fewer moths captured.   The current population continues to be an economic threat.  It is important to use effective materials to manage this pest on silking corn.  Insecticides in the IRAC 28 class (Coragen, Besiege, Exirel) and IRAC 5 (Radiant, Blackhawk, Entrust (OMRI approved)) remain among the most useful insecticides against CEW.

The highest nightly trap catches of CEW in pheromone traps for the week ending 9/30/20 are as follows:

Silking Spray Schedules*:
South – 3 days

Central – 3-4  days

North – 4-5 days

*These recommendations are based on regional catches.  Adhere to tighter spray schedules if indicated by local trap catches.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn, or for fall armyworm (FAW) management at any stage.  Control with these materials is very inconsistent.

Note:  Next week (10/07/20) will be the final regular edition of the Vegetable IPM Update for 2020.  We will post alerts should special pest situations arise.

Sweet Corn

Corn earworm (CEW) moth captures continue to decline, although with temporary increases on warm nights.    Growers should consider this pest to still be at moderate population levels in the state, with higher risk during stretches of warmer nights.   The current population poses a significant risk to silking corn.  Green areas on this map (see map at left)   represent a 3-day spray schedule.  However, night temperatures in the 40 to low 50 F range, may permit the extension of that spray interval by a day.  For further information on CEW activity, see pheromone trap information below.

The highest nightly trap catches of CEW in black light traps for the week ending 9/30/20 are as follows:

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Sweet Corn

Corn earworm (CEW) moth captures have declined dramatically with cold night temperatures.  As nights warm again toward the weekend, we may see some recovery in adult activity.  Growers should consider this pest to still be at moderately high population levels in the state unless warmer nights indicate that the threat has diminished.     The current population poses a significant risk to silking corn.  Green areas on this map (see map at left)   represent a 3-day spray schedule.  However, night temperatures in the 40 to low 50 F range, may permit the extension of that spray interval by a day.  For further information on CEW activity, see pheromone trap information below.

The highest nightly trap catches of CEW in black light traps for the week ending 9/23/20 are as follows:

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Sweet Corn

Fall armyworm (FAW) larval infestations remain at low levels in the few remaining sweet corn plantings not yet silking.  At this point in the season, FAW shouldn’t become a widespread economic problem.  However, growers should be alert to the possibility of infestations on the last of their late plantings.   Injury from newly hatched larvae shows up as “window panes” or areas where leaf tissue has been eaten down the the lower epidermis. This injury leads down into the whorl.  As larvae gain size, they begin to consume leaf tissue in its’ entirety, creating ragged holes and lots of droppings.  FAW can be tough to manage because it is resistant to synthetic pyrethroid insecticides (IRAC 3A) and because larvae are often covered by their own droppings, making contact with the insecticide more difficult.  Treat when 12% or more plants exhibit FAW injury alone, or in combination with ECB injury.

Corn earworm (CEW) moth captures continued a gradual decline over this past week due to several nights with low temperatures.  The decline is less noticeable in the northern counties, where CEW blacklight catches had been quite high prior to the onset of cooler weather.  Therefore the weekly averages there are higher.  Overall, these catches are representative of lower adult activity, and growers should consider this pest to still be at moderately high population levels in the state.     The current population poses a significant risk to silking corn.  The reduction in CEW catch was not enough to substantially change this weeks map from last week (see map at left).  Green areas on this map representing a 3-day spray schedule.  For further information on CEW activity, see pheromone trap information below.

The highest nightly trap catches of CEW in black light traps for the week ending 9/16/20 are as follows:

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Sweet Corn

European corn borer (ECB) adults continue to be very low, and no map will appear in this edition.

Fall armyworm (FAW) larval infestations are at fairly low levels.  Infestations generally are in the single digits to below 20%, and with few plantings in the whorl stage at this point in the season, FAW shouldn’t become a widespread economic problem.  However, growers should be alert to the possibility of infestations on the last of their late plantings.   Injury from newly hatched larvae shows up as “window panes” or areas where leaf tissue has been eaten down the the lower epidermis. This injury leads down into the whorl.  As larvae gain size, they begin to consume leaf tissue in its’ entirety, creating ragged holes and lots of droppings.  FAW can be tough to manage because it is resistant to synthetic pyrethroid insecticides (IRAC 3A) and because larvae are often covered by their own droppings, making contact with the insecticide more difficult.  Treat when 12% or more plants exhibit FAW injury alone, or in combination with ECB injury.

Corn earworm (CEW) moth captures have decreased slightly over the past week.  This is likely due to several nights with temperatures dropping into the low 60s and even 50s F.  The decline is representative of lower adult activity, and growers should consider this pest to still be at moderately high population levels in the state.     The current population poses a significant risk to silking corn.  The reduction in CEW catch was not enough to substantially change this weeks map from last week (see map at left).  Green areas on this map representing a 3-day spray schedule.  For further information on CEW activity, see pheromone trap information below.

The highest nightly trap catches of CEW in black light traps for the week ending 9/09/20 are as follows:

[Read more…]

Sweet Corn

European corn borer (ECB) adults continue to be very low, and no map will appear in this edition.

Fall armyworm (FAW) larval infestations have declined to fairly low levels.  Infestations generally are in the single digits to below 20%, but  FAW could increase dramatically with the arrival of  storms, resulting in significant injury to whorl and even seedling stage corn.  Injury from newly hatched larvae shows up as “window panes” or areas where leaf tissue has been eaten down the the lower epidermis. This injury leads down into the whorl.  As larvae gain size, they begin to consume leaf tissue in its’ entirety, creating ragged holes and lots of droppings.  FAW can be tough to manage because it is resistant to synthetic pyrethroid insecticides (IRAC 3A) and because larvae are often covered by their own droppings, making contact with the insecticide more difficult.  Treat when 12% or more plants exhibit FAW injury alone, or in combination with ECB injury.

Corn earworm (CEW) moth captures increased through late last week, and then declined in the past 4 nights due to cooler temperatures.  This decline may be temporary, as we get into warmer weather late this week and into the weekend.  The current population poses a significant risk to silking corn.  Catches remain somewhat variable (see map at left), with green areas on this map representing a 3-day spray schedule.  For further information on CEW activity, see pheromone trap information below.

The highest nightly trap catches of CEW in black light traps for the week ending 9/02/20 are as follows:

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