PestWatch Report on August 15, 2017

Corn earworm are starting to spike in southeastern PA, and remain stubbornly high in Erie County and to the southwest near Pittsburgh.
PestWatch Report on August 15, 2017 - News

Updated: April 9, 2018

PestWatch Report on August 15, 2017

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

Corn earworm (CEW) counts showed sharp increases in southeast PA, with a dramatic spike in New Danville, Lancaster County That site reached a 3-4 day spray interval. Additional sites suggesting a 4-5 day interval occurred in other sites in Lancaster County, as well as sites in Bucks and York counties. Sites suggesting a 5-6 day interval were reported in Erie and Washington counties. Counts can change rapidly at this time of year.

European corn borer (ECB) counts are low.

Fall armyworm (FAW) counts are also low, except in Erie County, and sites in New York. These appear to be following a pattern of the movement in from the Midwest.

Spray thresholds for CEW are being exceeded in Bucks, Lancaster, York, Erie and Washington counties. The spike in one site in Lancaster County reached a 3-4 day suggested spray threshold. The other two pests, ECB and FAW, are low, except for FAW in Erie County.

Also be aware that brown marmorated stink bug tends to move into sweet corn in August.

CountyFarm/Trap NameCEW
1-Aug
CEW
8-Aug
CEW
15-Aug
ECB
1-Aug
ECB
8-Aug
ECB
15-Aug
FAW
1-Aug
FAW
8-Aug
FAW
15-Aug
BlairCurryville, PA000000000
BlairHollidaysburg, PA000000003
BlairTyrone, PA6null00null06null0
BradfordBristol's Producenull0nullnull2.1nullnull1.4null
BradfordLarue's Producenull0nullnull1.5nullnull4.2null
BradfordShores Sisters Producenull0nullnull9.1null
BucksBedminster072003
BucksBuckingham7null4523.5null3
CentreHarner21.8null00.9null10null
CentreRock Springs2.63null25.3null82.6null
CentreStormstown25.3null00null166.1null
ClintonLogantonnull20null10.56
ErieDudas Farm601919
ErieMason533815182222
FayetteDuda's Farm Inc.17nullnull10nullnull0nullnull
HuntingdonNew Morning Farm1477494.77
IndianaBrush Valley204001145
IndianaCreekside002202
LackawannaRansom0nullnull3nullnull
LancasterLandisville01667101000
LancasterNeffsvillenull1821null02null00
LancasterNew Danville144280742200
LehighGermansville182null00null350
LuzerneDrums01null40null
LuzernePlains0nullnull2nullnull
LycomingLinden010120
LycomingMontoursville4811111
LycomingMuncy1110235
MontourMontournull2nullnull0null
NorthamptonNazarethnull0nullnull0.9nullnull0null
SchuylkillTower City000000470
WashingtonVenetia10722.5105
WestmorelandSchramms Farms and Orchard18.7null5.53.7null0
YorkYorknull3.545null42null00

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.