Monitoring sweet corn for pest moth activity can help reduce the number of insecticide applications.  At Kentland Farm in Whitethorne, VA, we recently harvested the first of several tests, where we followed an IPM approach and compared it to sprays of the pyrethroid lambda-cyhalothrin 3 times per week during silking.  We saw no difference in the level of control from an IPM approach- only spraying when needed and spraying the diamide Coragen first compared with the frequent lambda pyrethroid sprays.   We will be harvesting multiple sites for this experiment and will share these when all of the data are in.  Several commercial sweet corn farms are still being monitored around Virginia for corn earworm and fall armyworm.  However, many fields have been harvested already and trapping has been discontinued.  Moth Trap Catch Data are being recorded by:  Katlyn Catron  (Montgomery Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (Accomack Co. & Virginia Beach); Kenner Love (Rappahannock Co.); Laura Maxey Nay (Hanover Co.); Steve Pottorff (Carrol Co.); Stephanie Romelczyk  (Westmoreland Co.); Laura Siegle (Amelia Co.); and Mark Sutphin (Frederick Co.).

This week we observed general drop-off in corn earworm moth catch at many locations, but a big jump in numbers in Rockingham County in the Shenandoah Valley.  Fall armyworm moths never really amounted to anything this year. For corn earworm, moth trap catch of less than 1 per night means  low pest pressure and sweet corn sprays can probably be spaced 5-6 days apart during silking.  However, a catch of >1 or >13 moths per night means moderate and high pest pressure, respectively, and a more frequent spray interval (every 3 or 2 days) is justified.  Here are the trap catch results (moths per night) for several locations around Virginia for this week (note we do not have data for all locations):

Large corn earworm larva in sweet corn soon getting ready to exit the ear to pupate in the ground.

Monitoring sweet corn for pest moth activity can help reduce the number of insecticide applications.  At Kentland Farm in Whitethorne, VA, we recently harvested the first of several tests, where we followed an IPM approach and compared it to sprays of the pyrethroid lambda-cyhalothrin 3 times per week during silking.  We saw no difference in the level of control from an IPM approach- only spraying when needed and spraying the diamide Coragen first compared with the frequent lambda pyrethroid sprays.   We will be harvesting multiple sites for this experiment and will share these when all of the data are in.  Commercial sweet corn farms are being monitored around Virginia for corn earworm and fall armyworm.  Moth Trap Catch Data are being recorded by:  Katlyn Catron  (Montgomery Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (Accomack Co. & Virginia Beach); Kenner Love (Rappahannock Co.); Laura Maxey Nay (Hanover Co.); Steve Pottorff (Carrol Co.); Stephanie Romelczyk  (Westmoreland Co.); Laura Siegle (Amelia Co.); Rebekah Slabach (Halifax Co.); and Mark Sutphin (Frederick Co.).

This week we continued to observe moderate (above threshold) corn earworm moth catch at many locations, to warrant continued spraying.  Some of the areas with the highest CEW activity continue to be the Eastern Shore, and Frederick Co.; however, CEW moth catch has increased in Westmoreland, Rockinham, and Hanover Co.   We still have seen few to no fall armyworm moths yet. For corn earworm, moth trap catch of less than 1 per night means  low pest pressure and sweet corn sprays can probably be spaced 5-6 days apart during silking.  However, a catch of >1 or >13 moths per night means moderate and high pest pressure, respectively, and a more frequent spray interval (every 3 or 2 days) is justified.  Here are the trap catch results (moths per night) for several locations around Virginia for this week (note we do not have data for all locations):

Although corn is not insect pollinated, it doesn’t mean that it doesn’t attract a lot of bees gathering up pollen from the tassels (Fig. 1).  Pyrethroid insecticides are quite toxic to bees, so spraying them during pollen shed will undoubtedly result in some bee kills.  What can you do if you need to protect your corn from “worm” pests?  Spraying an insecticide with low toxicity to bees (i.e., Coragen) during pollen shed can help.  Also monitoring for pest activity and possibly limiting the number of sprays can also help.

Honey bees gathering pollen from sweet corn at Kentland Farm in Whitethorne, VA.

Sweet corn farms are being monitored around Virginia for corn earworm and fall armyworm.  Moth Trap Catch Data are being recorded by:  Katlyn Catron  (Montgomery Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (Accomack Co. & Virginia Beach); Kenner Love (Rappahannock Co.); Laura Maxey Nay (Hanover Co.); Steve Pottorff (Carrol Co.); Stephanie Romelczyk  (Westmoreland Co.); Laura Siegle (Amelia Co.); Rebekah Slabach (Halifax Co.); and Mark Sutphin (Frederick Co.).

Male corn earworm moth on Heliothis Trap.

This week we continued to observe high corn earworm moth catch at many locations, to warrant frequent spraying.  Some of the areas with the highest CEW activity were on the Eastern Shore, Virginia Beach, Frederick Co., Montgomery Co. and Hanover Co.   We still have not seen very many  fall armyworm moths yet. For corn earworm, moth trap catch of less than 1 per night means  low pest pressure and sweet corn sprays can probably be spaced 5-6 days apart during silking.  However, a catch of >1 or >13 moths per night means moderate and high pest pressure, respectively, and a more frequent spray interval (every 3 or 2 days) is justified.  Here are the trap catch results (moths per night) for several locations around Virginia for this week (note we do not have data for all locations):

Corn earworm larva developing fine on Bt sweet corn in Page County, VA.  Photo by Kenner Love, VCE.

Sweet corn farms are being monitored around Virginia for corn earworm and fall armyworm.  Moth Trap Catch Data are being recorded by:  Katlyn Catron  (Montgomery Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (Accomack Co. & Virginia Beach); Kenner Love (Rappahannock Co.); Laura Maxey Nay (Hanover Co.); Steve Pottorff (Carrol Co.); Stephanie Romelczyk  (Westmoreland Co.); Laura Siegle (Amelia Co.); Rebekah Slabach (Halifax Co.); and Mark Sutphin (Frederick Co.).

Male corn earworm moth on Heliothis Trap.

This week we observed a general increase in corn earworm moth catch at many locations, to warrant frequent spraying.  Some of the areas with the highest CEW activity were on the Eastern Shore, Virginia Beach, Frederick Co., Montgomery Co. and Hanover Co.   We still have not seen very many  fall armyworm moths yet. For corn earworm, moth trap catch of less than 1 per night means  low pest pressure and sweet corn sprays can probably be spaced 5-6 days apart during silking.  However, a catch of >1 or >13 moths per night means moderate and high pest pressure, respectively, and a more frequent spray interval (every 3 or 2 days) is justified.  Here are the trap catch results (moths per night) for several locations around Virginia for this week (note we do not have data for all locations):

Corn earworm larva in Bt sweet corn in Page County, VA. Photo by Kenner Love, VCE.

Sweet corn farms are being monitored around Virginia for corn earworm and fall armyworm.  Moth Trap Catch Data are being recorded by:  Katlyn Catron  (Montgomery Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (Accomack Co. & Virginia Beach); Kenner Love (Rappahannock Co.); Laura Maxey Nay (Hanover Co.); Steve Pottorff (Carrol Co.); Stephanie Romelczyk  (Westmoreland Co.); Laura Siegle (Amelia Co.); Rebekah Slabach (Halifax Co.); and Mark Sutphin (Frederick Co.).

This week we observed a general drop off in corn earworm moth catch at many locations, but still enough moth flight activity to warrant frequent spraying in many locations such as the Bridge Tunnel in Northampton County, Virginia Beach, Frederick Co., and Hanover Co.   We still have not seen very many  fall armyworm moths yet. For corn earworm, moth trap catch of less than 1 per night means  low pest pressure and sweet corn sprays can probably be spaced 5-6 days apart during silking.  However, a catch of >1 or >13 moths per night means moderate and high pest pressure, respectively, and a more frequent spray interval (every 3 or 2 days) is justified.  Here are the trap catch results (moths per night) for several locations around Virginia for this week (note we do not have data for all locations):

Sweet corn farms are being monitored around Virginia for the two most important pests attacking the ears, corn earworm and fall armyworm.  Moth Trap Catch Data are being recorded by:  Katlyn Catron  (Montgomery Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (Accomack Co. & Virginia Beach); Kenner Love (Rappahannock Co.); Laura Maxey Nay (Hanover Co.); Steve Pottorff (Carrol Co.); Stephanie Romelczyk  (Westmoreland Co.); Laura Siegle (Amelia Co.); Rebekah Slabach (Halifax Co.); and Mark Sutphin (Frederick Co.).

This week we observed some big jumps in corn earworm moth catch at some locations such as the Bridge Tunnel in Northampton County, the ESAREC in Accomack Co., and Hanover Co.   We still have not seen very many  fall armyworm moths yet, only a few moths here and there in VA. For corn earworm, moth trap catch of less than 1 per night means  low pest pressure and sweet corn sprays can probably be spaced 5-6 days apart during silking.  However, a catch of >1 or >13 moths per night means moderate and high pest pressure, respectively, and a more frequent spray interval (every 3 or 2 days) is justified.  Here are the trap catch results (moths per night) for several locations around Virginia for this week (note we do not have data for all locations):

This project is sponsored by a Specialty Crop Block Grant by VDACS.

Sweet corn farms are being monitored around Virginia for the two most important pests attacking the ears, corn earworm and fall armyworm.  Moth Trap Catch Data are being recorded by:  Katlyn Catron & John Few (Montgomery Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (Accomack Co. & Virginia Beach); Kenner Love (Rappahannock Co.); Laura Maxey Nay (Hanover Co.); Steve Pottorff (Carrol Co.); Stephanie Romelczyk  (Westmoreland Co.); Laura Siegle (Amelia Co.); Rebekah Slabach (Halifax Co.); and Mark Sutphin (Frederick Co.).

This week we have still not seen the fall armyworm flight yet in VA.  A few moths were caught on the Eastern Shore of VA and a couple other locations, but generally they are not in Virginia yet from their migratory flight from the south each summer.  For corn earworm, trap catch of less than 1 per night means relatively low pest pressure and sprays can probably be spaced 5-6 days apart during silking.  However, a catch of >1 or >13 moths per night means moderate and high pest pressure, respectively and a more frequent spray interval (every 3 or 2 days) is justified.  Trap catch increased to high levels on several farms this week throughout the state including Northampton Co., Virginia Beach, Page Co., and Montgomery Co.

Here are the trap catch results (moths per night) for several locations around Virginia for this week (note we do not have data for all locations):