PestWatch Report - September 6, 2017

Corn earworm counts spiked to a 3-4 day threshold in Erie, Lycoming, Washington, Westmoreland, and York Counties.
PestWatch Report - September 6, 2017 - News

Updated: October 12, 2017

PestWatch Report - September 6, 2017

Corn earworm adult moth.

Many additional sites are above a 4-5, or 5-6, day spray threshold for CEW. Corn earworm (CEW) counts continued to spike, reaching to a 3-4 day thresholds in Erie, Lycoming, Washington, Westmoreland, and York Counties in the last week or two. Many additional sites along the west, south, and eastern portions of PA advanced to a 4-5 day spray interval. Eggs take about 2-3 days to hatch, and1st instar larvae an additional 2-3 days to move into the ear if you have a tight-husked cultivar. Therefore, if you are within 4-6 days to harvest, there is no need to use sprays to prevent CEW larvae in the ear.

European corn borer (ECB) counts are high in Luzern County. All other sites are low.

Fall armyworm (FAW) counts are high in Erie County, and increased also occurred south of Pittsburgh and in Lycoming County.

CountyFarm/Trap NameCEWCEWCEWECBECBECBFAWFAWFAW
23-Aug30-Aug6-Sep23-Aug30-Aug6-Sep23-Aug30-Aug6-Sep
BlairCurryville, PA21nullnull0nullnull2nullnull
BlairHollidaysburg, PA20nullnull0nullnull7nullnull
BlairTyrone, PA30nullnull0nullnull9nullnull
BradfordBristol's Producenullnullnullnullnullnull
BradfordLarue's Producenullnullnullnullnull
BradfordShores Sisters Producenullnullnullnullnullnull
BucksBedminster47null3.50nullnull
BucksBuckinghamnull40nullnull0null
CentreHarnernullnullnullnullnullnullnullnullnull
CentreRock Springsnullnullnullnullnullnullnullnullnull
CentreStormstownnullnullnullnullnullnullnullnullnull
ClintonLogantonnull00331.6
ErieDudas Farm33389.32659273.9
ErieMason40127174.144112288.8
FayetteDuda's Farm Inc.4887null05null814null
HuntingdonNew Morning Farm19.89.371.201.8
IndianaBrush Valley629null35null
IndianaCreekside628null00null01null
LancasterLandisville44.6404.431002
LancasterNeffsville52.521117.922002
LancasterNew Danville5338null00null110null
LehighGermansvillenullnullnullnullnullnullnull
LuzerneDrums220067541027
LuzernePlains2030null65null
LycomingLindennull0nullnull0null
LycomingMontoursvillenull28nullnull4.7null
LycomingMuncynull82.8nullnull7null
MontourMontour817null84null
NorthamptonNazareth1nullnull4nullnull00null
SchuylkillTower City010000004.74
WashingtonVenetia468632nullnullnullnull7null
WestmorelandSchramms Farms and Orchardnull101.3nullnull0null
YorkYork6015592.8103.5062.6

Thresholds

Reproductive (tassel/silk) and late vegetative corn attracts moths. Shorten spray schedules when populations increase.

Thresholds Based on CEW Captures

Levels CEW catch / week Spray frequency
almost absent1-134 days to no spray
very low14-355 to 6 day
low36-704 to 5 day
moderate71-3493 to 4 day
high> 3502 to 3 day

If CEW is low, then consider ECB

Levels ECB catch / week Spray frequency
almost absent< 14no treatment
very low15-356 day
low38-705 day
moderate> 704 day
high

Authors

Insect population dynamics IPM

More by Shelby Fleischer, Ph.D.