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Pest Watch July 17, 2015

Posted: July 16, 2015

Most sites continue to report very low counts for moth pests, but a 2nd generation of ECB has started, a few sites in western and central PA reported FAW, and sap beetles have emerged in some southeastern sites when worm sprays were removed. Inspect silks for sap beetles.
Corn Earworm Photo credit H. Fescemyer

Corn Earworm Photo credit H. Fescemyer

Historically, sap beetles tend to be a bigger problem on diversified farms with a reservoir of free sugars (strawberries, melons, etc.,) and in sweet corn varieties without a strong and tight silk tube. Wide spray intervals should be sufficient for sap beetles. Inspect fields for signs of foliar feeding from FAW. In most sites, wide spray intervals should be sufficient. Changes to this can occur rapidly at this time of year.

Sap beetles have been reported seriously damaging unsprayed corn in the southeast. Typically, sap beetles have been a bigger problem in the south and eastern portion of PA.

sap beetle

Sap beetle adults and larvae. Photo credits: G. Dively

Corn earworm (CEW)

Trap counts continue to be below thresholds. Moving traps so they are near silking corn will help maintain sensitivity of traps.

County CEW Trap Name July 4 July 11 July 18
Blair Curryville, PA (Blair)
3 1

Hollidaysburg, PA (Blair)
1 1

Tyrone, PA (Blair)
0 0
Bradford Bristol's Produce 0
0

Shores Sisters Produce 0 1 0
Bucks Bedminster 0 0 0

Buckingham 1 1 2
Centre Harner 0 1 0

Rock Springs 1 0 1

Stormstown 0 1 1
Clinton Sunnyside Produce 1 1
Erie Mason

0
Fayette Duda's Farm Inc. 1 1 1
Huntingdon New Morning Farm 0 0 0
Indiana Creekside 1
0
Lancaster Landisville 0 0 1

Neffsville 0 1 1

New Danville 1 1 2
Lehigh Germansville 1

Luzerne Drums 0 0 0

Plains 0 0
Lycoming Linden 1 0

Montoursville 1 1

Muncy 1 0
Mifflin Streamside Produce 1 2 1
Montgomery Harleysville - Landis 0
1

Souderton - Frankenfield 6 3 2
Montour Montour 1 1 1
Northampton Nazareth 0
0
Schuylkill Friedensburg 1 0

L. Hetherington Farm
1 0
Washington Venetia 2 1 1
Westmoreland Schramms Farms and Orchard
1
York York 0 0 0
Schuylkill Tower City 1 0 0

European corn borer (ECB)

A second generation has started, and exceeding thresholds for wide spray intervals in Bradford, Fayette, and Centre Counties.  Most sites are low. Region-wide planting of Bt-field corn, for multiple years, has been reducing populations of ECB.

European corn borer adults and larva

European corn borer Photo credit M.E.Rice

County ECB Trap Name July 4 July 11 July 18
Blair Curryville, PA

0 0

Hollidaysburg, PA
1 0

Second Trap



Tyrone, PA

1 0
Bradford Bristol's Produce 0
0

Shores Sisters Produce 0 0 5
Bucks Bedminster 0 0 0

Buckingham 0 0 0
Centre Harner 1 4 3

Rock Springs 0 1 1

Stormstown 0 0 0
Clinton Sunnyside Produce 0 0
Fayette Duda's Farm Inc. 1
3
Huntingdon New Morning Farm 0
0
Indiana Creekside 0
1
Lancaster Landisville 1 1 1

Neffsville 1 0 0

New Danville 0 0 0
Lehigh Germansville 1

Luzerne Drums 0 0 0

Plains 3 3
Montgomery Harleysville - Landis 1
0

Souderton - Frankenfield 0 1 1
Montour Montour 1 1 1
Northampton Nazareth 1
0
Schuylkill Friedensburg 0 0

L.Hetherington Farm
1 0
Westmoreland Schramms Farms and Orchard
0
York York 0 0 0
Schuylkill Tower City 1 1 0

Fall armyworms (FAW)

Although most sites are low, multiple sites in Centre and Fayette Counties had significant captures.  Typically, we see more FAW in the western and central portions of PA.  Among the 3 worm pests, our ability to detect FAW migration is the least sensitive, especially this early in the season.  It is not uncommon for sporadic reports of damage prior to significant moth capture, and this may have occurred in Huntington Co. last week. The larva will go directly into ears, but at this time of year we typically see foliar feeding as well.

FAW feeding

Fall armyworm foliar feeding –‘tearing’, ‘ragging’, lots of frass.  Photo credit R. Meagher

County FAW Trap Name July 4 July 11 July 18
Blair Curryville, PA
0 1

Hollidaysburg, PA
0 1

Tyrone, PA
0 0
Centre Harner 1 1 1

Rock Springs 1 1 2

Stormstown 1 1 4
Erie Mason

1
Fayette Duda's Farm Inc. 0
2
Indiana Creekside 0
0
Lancaster Landisville 0 0 0

Neffsville 0 0 0

New Danville 0 0 0
Lehigh Germansville 0

Luzerne Drums

0
Lycoming Linden 1 0

Montoursville 1 0

Muncy 0 0
Mifflin Streamside Produce 0 0 0
Northampton Nazareth 0
0
Schuylkill Friedensburg 0 0

L.Hetherington Farm
0 1
York York 0 0 0
Schuylkill Tower City 0 1 0

Values in tables estimate catch-per-night for the week ending in the indicated date.  Multiply by 7 to estimate catch-per-week.

Level
CEW catch / night Spray frequency
almost absent < 2 4 days to no spray
very low 3 to 5 5 to 6 day
low 6 to 10 4 to 5 day
moderate 11 to 50 3 to 4 day
high > 50 2 to 3 day
Level
ECB catch / night Spray frequency
almost absent < 2 no treatment
very low 3 to 5 6 day
low 6 to 10 5 day
moderate > 10 4 day
high

Contact Information

Shelby Fleischer
  • Professor of Entomology
Email:
Phone: 814-863-7788