PestWatch Report on August 23, 2017

Most sites are above a 4-5, or 5-6, day spray threshold for corn earworm.
PestWatch Report on August 23, 2017 - News

Updated: October 5, 2017

PestWatch Report on August 23, 2017

Corn earworm trap in Montgomery County, PA. Photo: A. Frankenfield, Penn State

Corn earworm (CEW) counts continued to increase. Counties along the west, south, and eastern portions of PA were at a 4-5 day spray interval. Counties more towards the center of the state were a bit lower, at a 5-6 day interval. Counts in other parts of the US are also increasing, and counts can change rapidly at this time of year.

European corn borer (ECB) counts are low, but one site in northeastern PA had a marked increase within the last few days.

Fall armyworm (FAW) counts are high in Erie County, and sites in the mid-central portion of the state showed plant damage in the presence of low counts.

CountyFarm/Trap NameCEW
8-Aug
CEW
15-Aug
CEW
23-Aug
ECB
8-Aug
ECB
15-Aug
ECB
23-Aug
FAW
8-Aug
FAW
15-Aug
FAW
23-Aug
BlairCurryville, PA0021000002
BlairHollidaysburg, PA0020000037
BlairTyrone, PAnull030null00null09
BradfordBristol's Produce0nullnull2.1nullnull1.4nullnull
BradfordLarue's Produce0nullnull1.5nullnull4.2null
BradfordShores Sisters Produce0nullnull9.1nullnullnull
BucksBedminster7247030
BucksBuckinghamnull45nullnull3null
CentreHarner1.8nullnull0.9nullnull0nullnull
CentreRock Springs3nullnull5.3nullnull2.6nullnull
CentreStormstown5.3nullnull0nullnull6.1nullnull
ClintonLoganton20null10.563
ErieDudas Farm0131926
ErieMason381540222244
FayetteDuda's Farm Inc.nullnull48nullnull0nullnull8
HuntingdonNew Morning Farm7719.84.771.2
IndianaBrush Valley04601453
IndianaCreekside0260020
LackawannaRansomnullnullnullnullnullnull
LancasterLandisville16644.61014.4000
LancasterNeffsville182152.5027.9000
LancasterNew Danville4280534200011
LehighGermansville2nullnull0nullnull50null
LuzerneDrums1null20null6
LuzernePlainsnullnull20nullnull6
LycomingLinden10null20null
LycomingMontoursville81null111null
LycomingMuncy10null35null
MontourMontour2null80null8
NorthamptonNazareth0null10.9null40null0
SchuylkillTower City000000700
WashingtonVenetia722.546null105null
WestmorelandSchramms Farms and Orchardnull5.5nullnull0null
YorkYork3.54560421000

Thresholds

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

Thresholds Based on CEW Captures

LevelsCEW catch / weekSpray 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

LevelsECB catch / weekSpray 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.