Author Archives: Thomas Kuhar

About Thomas Kuhar

Professor and VCE-Vegetable Entomology Specialist Department of Entomology Virginia Tech Blacksburg, VA

Sweet corn moth trap monitoring in VA – Week of Aug 27, 2017

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):

Week of Aug 27 (avg)
Region County Field CEW/night FAW/night
Eastern Shore Accomack ESAREC – cemetery 3.1 NA
Eastern Shore Accomack ESAREC – woods NA NA
Eastern Shore Accomack ESAREC – sweet corn 2.5 0
Eastern Shore Northampton Bridge Tunnel NA NA
Eastern Shore Northampton Capeville 1 NA 0
Eastern Shore Northampton Cape charles NA NA
Eastern Shore Northampton Eastville NA 0.2
Eastern Shore Northampton Nassawaddox NA 0.4
Virginia Beach Virginia Beach Pungo 1 NA NA
Piedmont Amelia Field 1 NA NA
Piedmont Hanover Farm 1 NA 0.4
Piedmont Hanover Haynes NA NA
Northern Neck Westmoreland Field 1 1.0 0.0
Northern Neck Westmoreland Field 2 NA NA
Shenandoah Valley Rappahannock Field 1 2.7 0
Shenandoah Valley Page Field 1 NA NA
Shenandoah Valley Frederick Farm 1 10.5 0
Shenandoah Valley Frederick Farm 2 15.5 0
Shenandoah Valley Rockingham Farm 1 18.1 0
Shenandoah Valley Rockingham Farm 2 NA NA
New River Valley Montgomery KC 0 0
New River Valley Montgomery KO1 1 0
New River Valley Montgomery KO2 1 NA
New River Valley Montgomery WF1 0 NA
New River Valley Montgomery WF2 0 NA
New River Valley Montgomery WF3 0 NA
New River Valley Montgomery WS1 1 NA
New River Valley Montgomery WS2 0 NA
New River Valley Montgomery WS3 1 NA
Southwest Carroll NA NA

Sweetcorn insect pest monitoring across VA for week of Aug 20, 2017

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):

Week of Aug 20 (avg)
Region County Field CEW/night FAW/night
Eastern Shore Accomack ESAREC – cemetery 1.4 NA
Eastern Shore Accomack ESAREC – woods NA NA
Eastern Shore Accomack ESAREC – sweet corn 1.4 0.2
Eastern Shore Northampton Bridge Tunnel 8.4 NA
Eastern Shore Northampton Capeville 1 1.3 0
Eastern Shore Northampton Cape charles 1.1 NA
Eastern Shore Northampton Eastville 5.3 0.2
Eastern Shore Northampton Nassawaddox 0.6 0.4
Virginia Beach Virginia Beach Pungo 1 NA NA
Piedmont Amelia Field 1 NA NA
Piedmont Hanover Farm 1 3.4 0.4
Piedmont Hanover Haynes NA NA
Northern Neck Westmoreland Field 1 7.0 0.6
Northern Neck Westmoreland Field 2 NA NA
Shenandoah Valley Rappahannock Field 1 3.5 0
Shenandoah Valley Page Field 1 NA NA
Shenandoah Valley Frederick Farm 1 5.6 0
Shenandoah Valley Frederick Farm 2 14.4 0
Shenandoah Valley Rockingham Farm 1 6.4 0
Shenandoah Valley Rockingham Farm 2 NA NA
New River Valley Montgomery KC NA NA
New River Valley Montgomery KO1 NA NA
New River Valley Montgomery KO2 NA NA
New River Valley Montgomery WF1 NA NA
New River Valley Montgomery WF2 NA NA
New River Valley Montgomery WF3 NA NA
New River Valley Montgomery WS1 NA NA
New River Valley Montgomery WS2 NA NA
New River Valley Montgomery WS3 NA NA
Southwest Carroll NA NA

Sweet corn pest monitoring in VA – Moth trap catch for week of Aug 13th

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):

Week of Aug 13 (avg)
Region County Field CEW/night FAW/night
Eastern Shore Accomack ESAREC – cemetery 7.0 NA
Eastern Shore Accomack ESAREC – woods 0.2 NA
Eastern Shore Accomack ESAREC – sweet corn 19.7 0.2
Eastern Shore Northampton Bridge Tunnel 12.1 NA
Eastern Shore Northampton Capeville 1 0.8 0.5
Eastern Shore Northampton Cape charles 1.2 NA
Eastern Shore Northampton Eastville 3.1 0.8
Eastern Shore Northampton Nassawaddox 0.1 2
Virginia Beach Virginia Beach Pungo 1 16.1 0.7
Piedmont Amelia Field 1 NA NA
Piedmont Hanover Farm 1 3.5 0.5
Piedmont Hanover Haynes NA NA
Northern Neck Westmoreland Field 1 0.6 0.0
Northern Neck Westmoreland Field 2 NA NA
Shenandoah Valley Rappahannock Field 1 2.8 0.2
Shenandoah Valley Page Field 1 0.1 0
Shenandoah Valley Frederick Farm 1 5.6 0
Shenandoah Valley Frederick Farm 2 14.4 0
Shenandoah Valley Rockingham Farm 1 NA NA
Shenandoah Valley Rockingham Farm 2 NA NA
New River Valley Montgomery KC 0.9 0
New River Valley Montgomery KO1 4.9 0
New River Valley Montgomery KO2 9.4 0
New River Valley Montgomery WF1 1.1 NA
New River Valley Montgomery WF2 0.6 NA
New River Valley Montgomery WF3 0.7 NA
New River Valley Montgomery WS1 2.4 NA
New River Valley Montgomery WS2 0.9 NA
New River Valley Montgomery WS3 2.6 NA
Southwest Carroll NA NA

Sweet corn sampling across Virginia – Moth Catch for Week of Aug 6-10

 

 

 

 

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):

Week of Aug 6 (avg)
Region County Field CEW/night FAW/night
Eastern Shore Accomack ESAREC – cemetery 6.0 NA
Eastern Shore Accomack ESAREC – woods 0.2 NA
Eastern Shore Accomack ESAREC – sweet corn 18.6 0.9
Eastern Shore Northampton Bridge Tunnel 18.3 NA
Eastern Shore Northampton Capeville 1 1.0 0
Eastern Shore Northampton Cape charles 3.0 NA
Eastern Shore Northampton Eastville 2.7 1.8
Eastern Shore Northampton Nassawaddox 0.3 0.3
Virginia Beach Virginia Beach Pungo 1 6.2 0.9
Piedmont Amelia Field 1 NA NA
Piedmont Hanover Farm 1 6.3 0.0
Piedmont Hanover Haynes NA NA
Northern Neck Westmoreland Field 1 NA NA
Northern Neck Westmoreland Field 2 NA NA
Shenandoah Valley Rappahannock Field 1 0.6 0.1
Shenandoah Valley Page Field 1 0.2 0.1
Shenandoah Valley Frederick Farm 1 6.1 0
Shenandoah Valley Frederick Farm 2 28.3 NA
Shenandoah Valley Rockingham Farm 1 3.4 NA
Shenandoah Valley Rockingham Farm 2 NA NA
New River Valley Montgomery KC 1.3 0
New River Valley Montgomery KO1 18.0 0
New River Valley Montgomery KO2 28.3 0
New River Valley Montgomery WF1 6.8 NA
New River Valley Montgomery WF2 1.3 NA
New River Valley Montgomery WF3 6.7 NA
New River Valley Montgomery WS1 8.8 NA
New River Valley Montgomery WS2 0.0 NA
New River Valley Montgomery WS3 4.5 NA
Southwest Carroll 0.3 0.5

Sweet corn sampling in VA – Moth trap counts for week of July 31

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):

Week of July 31 (avg)
Region County Field CEW/night FAW/night
Eastern Shore Accomack ESAREC – cemetery 6.3 0.1
Eastern Shore Accomack ESAREC – woods 0.0 NA
Eastern Shore Accomack ESAREC – sweet corn 1.1 0.1
Eastern Shore Northampton Bridge Tunnel 15.1 NA
Eastern Shore Northampton Capeville 1 0.6 0
Eastern Shore Northampton Cape charles 2.4 NA
Eastern Shore Northampton Eastville 2.3 1
Eastern Shore Northampton Nassawaddox 0.4 1
Virginia Beach Virginia Beach Pungo 1 11.6 0.3
Piedmont Amelia Field 1 NA NA
Piedmont Hanover Farm 1 7.8 0.0
Piedmont Hanover Haynes 6.9 0.0
Northern Neck Westmoreland Field 1 3.0 0
Northern Neck Westmoreland Field 2 NA NA
Shenandoah Valley Rappahannock Field 1 0.6 0.1
Shenandoah Valley Page Field 1 0.2 0.1
Shenandoah Valley Frederick Farm 1 1.4 0.9
Shenandoah Valley Frederick Farm 2 9.1 NA
Shenandoah Valley Rockingham Farm 1 NA NA
Shenandoah Valley Rockingham Farm 2 NA NA
New River Valley Montgomery KC 0.1 0
New River Valley Montgomery KO1 3.0 0
New River Valley Montgomery KO2 1.7 0
New River Valley Montgomery WF1 2.9 NA
New River Valley Montgomery WF2 1.1 NA
New River Valley Montgomery WF3 2.0 NA
New River Valley Montgomery WS1 2.3 NA
New River Valley Montgomery WS2 2.0 NA
New River Valley Montgomery WS3 1.7 NA

 

Sweet corn moth trap numbers for VA counties – week of July 24, 2017

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):

Week of July 24 (avg)
Region County Field CEW/night FAW/night
Eastern Shore Accomack ESAREC – cemetery 9.6 1
Eastern Shore Accomack ESAREC – woods 3.4 0
Eastern Shore Accomack ESAREC – sweet corn 4.6 0
Eastern Shore Northampton Bridge Tunnel 60.4 NA
Eastern Shore Northampton Capeville 1 2.1 0
Eastern Shore Northampton Cape charles 6.3 NA
Eastern Shore Northampton Eastville 10.6 1
Eastern Shore Northampton Nassawaddox 0.1 1
Virginia Beach Virginia Beach Pungo 1 11.9 1
Piedmont Amelia Field 1 NA NA
Piedmont Hanover Farm 1 11.0 0.0
Piedmont Hanover Haynes 3.9 0.0
Northern Neck Westmoreland Field 1 6.3 0
Northern Neck Westmoreland Field 2 NA NA
Shenandoah Valley Rappahannock Field 1 0.6 0
Shenandoah Valley Page Field 1 1.7 0
Shenandoah Valley Frederick Farm 1 1.4 1
Shenandoah Valley Frederick Farm 2 5.2 0
Shenandoah Valley Rockingham Farm 1 0.7 1
Shenandoah Valley Rockingham Farm 2 NA NA
New River Valley Montgomery KC 0.0 0
New River Valley Montgomery KO1 2.0 1
New River Valley Montgomery KO2 6.0 1
New River Valley Montgomery WF1 1.0 NA
New River Valley Montgomery WF2 0.0 NA
New River Valley Montgomery WF3 4.0 NA
New River Valley Montgomery WS1 0.0 NA
New River Valley Montgomery WS2 1.0 NA
New River Valley Montgomery WS3 1.0 NA

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

Corn earworm and Fall armyworm trap catch numbers from Virginia sweet corn fields – Week of July 16

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):

Week of July 16 (avg)
Region County Field CEW/night FAW/night
Eastern Shore Accomack ESAREC – cemetery 4.4 3
Eastern Shore Accomack ESAREC – woods 1.1 0
Eastern Shore Northampton Bridge Tunnel 33.3 0
Eastern Shore Northampton Capeville 1 1.5 0
Eastern Shore Northampton Cape charles 3.0 NA
Eastern Shore Northampton Eastville 4.5 0
Eastern Shore Northampton Nassawaddox 1.5 0
Virginia Beach Virginia Beach Pungo 1 15.7 0
Piedmont Amelia Field 1 4.0 0.2
Piedmont Hanover Farm 1 3.7 0.0
Piedmont Hanover Haynes 1.1 0.0
Northern Neck Westmoreland Field 1 10.0 0
Northern Neck Westmoreland Field 2 3.7 1
Shenandoah Valley Rappahannock Field 1 5.0 0
Shenandoah Valley Page Field 1 12.0 0
Shenandoah Valley Frederick Farm 1 7.4 0
Shenandoah Valley Frederick Farm 2 3.2 0
Shenandoah Valley Rockingham Farm 1 0.3 0
Shenandoah Valley Rockingham Farm 2 1.0 0
New River Valley Montgomery KC 1.0 0
New River Valley Montgomery KO1 3.3 0
New River Valley Montgomery KO2 9.3 0
New River Valley Montgomery WF1 16.3 NA
New River Valley Montgomery WF2 4.3 NA
New River Valley Montgomery WF3 13.0 NA
New River Valley Montgomery WS1 17.3 NA
New River Valley Montgomery WS2 19.0 NA
New River Valley Montgomery WS3 36.7 NA

Corn earworm and fall armyworm trap catch numbers in Virginia – Week of July 10, 2017

 

Corn earworm larva in sweet corn.

Corn earworm and fall armyworm are two important pests of a number of agricultural crops in Virginia.  Sweet corn, in particular, is extremely vulnerable to attack by the larvae (or caterpillars) of these moth pests.  Monitoring moth catch numbers in pheromone-baited traps can help IPM decision-making.  See at the end of this post the Action threshold for spraying insecticides on sweet corn based on corn earworm trap catch.  In general trap catch 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 is justified.

In 2017, we are monitoring these pests on sweet corn farms in 11 different counties in Virginia.  Moth Trap Catch Data are being recorded by:  Katlyn Catron & John Few (Montgomery Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (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.)

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):

Region County Field CEW  moths/night FAW moths/night
Eastern Shore Accomack ESAREC 1.1 0
Eastern Shore Virginia Beach Pungo 1 1.6 0
Eastern Shore Virginia Beach Pungo 2 3.9 0
Eastern Shore Northampton Bridge Tunnel 6.6 0
Eastern Shore Northampton Capeville 1 3.6 0
Eastern Shore Northampton Capeville 2 0.0 0
Eastern Shore Northampton Eastville 0.6 0
Eastern Shore Northampton Nassawaddox 1.0 0
Piedmont Amelia Field 1 2.7 0
Piedmont Hanover Field 1 2.1 0
Piedmont Hanover Field 2 1.0 0
Northern Neck Westmoreland Field 1 3.0 0
Shenandoah Valley Rappahannock Field 1 1.0 0
Shenandoah Valley Frederick Field 1 2.3 0
Shenandoah Valley Frederick Field 2 3.5 0
New River Valley Montgomery Whitethorne 1.9 0
New River Valley Montgomery Wall field corn 1.1 0
New River Valley Montgomery Wall sweet corn 20.8 0

 

Action threshold: Number of Corn Earworm Moths Caught in Pheromone trap
Per Day Per 5 Days Per Week Spray Interval for sweet corn
<0.2 <1 <1.4 No Spray
0.2 – 0.5 1.0 – 2.5 1.4 – 3.5 6 Day
0.5 – 1.0 2.5 – 5.0 3.5 – 7.0 5 Day
1.0 – 13.0 5.0 – 65.0 7.0 – 91.0 4 Day
>13.0 >65.0 >91.0 3 Day

 

 

Slug problems on corn

Slug damage on no-till corn.

Slug damage on no-till corn.

With all of the rain during the first week of May, and with seedling corn having emerged, we are hearing about slug pest problems, particularly in no-till corn.  Eastern Shore of Virginia is one area reporting issues.  Slug problems are a common concern in no-till systems when conditions are wet in the spring (see VCE Factsheet No. 444-109  https://pubs.ext.vt.edu/444/444-109/444-109.html) .  Another useful VCE factsheet on slug management in no-till corn from Bobby clark and Rod Youngman is:  http://offices.ext.vt.edu/shenandoah/programs/anr/CropandSoilEnvironmentalSciences/Slug_Fact_Sheet.pdf

Growers must keep four things in mind right off the bat: 1) corn plants are often not killed outright by the slugs and quite often have the ability to outgrow the leaf feeding injury by these slimy little beasts unless populations are very high and weather conditions are bad.  Soybean cotyledons, however, are more susceptible to being killed because their growing point can be damaged; 2) if it stops raining for a few days, then the slugs will go away and hide as they require high moisture levels; 3) replanting is an option, but a grower needs to factor in the economics see VCE Fact Sheet https://pubs.ext.vt.edu/2905/2905-1293/2905-1293_pdf;  and 4) if you are considering a chemical control measure, keep in mind that there are only a select few effective options such as slug bait products containing metaldehyde or iron phosphate.  These are not easy to apply (need to be broadcasted) and are fairly expensive.  However, these products are efficacious and will most often alleviate the slug problem long enough for your seedling plants to reach a sufficient size to no longer be economically damaged by slugs.  See VCE Fact sheet No. ENTO-178 for a recent efficacy evaluation that we did with slug baits.  http://pubs.ext.vt.edu/ENTO/ENTO-178/ENTO-178-PDF.pdf

 

Predator profile: Leatherwings (soldier beetles)

Beetles in the family Cantharidae are referred to as soldier beetles or leatherwings.  Two species in the genus Chauliognathus are commonly found in Virginia agricultural fields. Chauliognathus pennsylvanicus is often referred to as the Pennsylvania leatherwing, or the goldenrod soldier beetle referring to its favorite flowering plant in the fall. A similar species Chauliognathus marginatus, the margined leatherwing, is found in the spring on various flowers.

pennsylvania_leatherwing_Adult

Pennsylvania leatherwing beetle (above).

margined-leatherwing

Margined leatherwing beetle (above)

Description and Life History

Though soldier beetles resemble fireflies, they lack the light-producing organ on their abdomen and their head is not concealed from above. Cantharid beetles in general are elongate with soft and flexible elytra. The two Chauliognathus species range in size from 1/2 to 5/8-inch long, and have yellowish to orange elytra. Pennsylvania leatherwing has two prominent brown-black spots near the tips of the elytra and a black spot in the center of the pronotum. In contrast, the elytra of the margined leatherwing can vary considerably in the amount of dark markings and the dark marking on the pronotum is a band that reaches both the front and the back edge. Another way to differentiate these two species is the time period that the adults are present; Pennsylvania leatherwing adults are active in the fall and margined leatherwing adults are active in the spring. This is also important in regards to conservation biological control as flower resources need to be available in early spring for one species, and in late fall for the other.

Leatherwing beetles have one generation per year. Adults of both species typically feed and mate on flowers. Eggs are deposited in clusters in the soil, and hatch in ~10 days. Tiny neonate larvae are white-colored and display little or no activity until first molt. After about 24 h, they take on C shape. With each successive molt, the larvae darken in color until eventually reaching a black velvety appearance. Activity also increases as the larva develops. Leatherwing larvae are voracious predators consuming a multitude of soft-bodied insects.   A single predatory larva can consume several egg masses of Colorado potato beetle, or aphids, or small lepidopteran larvae in one day.  In the lab, they feed upon many different prey species.

Chaulignathus larva