PestWatch Report on July 6, 2017

Corn earworm (CEW) has been detected in all 30 trapping sites.
PestWatch Report on July 6, 2017 - News

Updated: August 8, 2017

PestWatch Report on July 6, 2017

Although counts declined in most locations since last week, a site in Lycoming increased to suggest a 4-5 day spray interval, and sites in Blair, Fayette, Lehigh, Westmoreland and York have been above 4-5 day spray thresholds during the last 2 weeks. Silking corn will strongly attract egg-laying females.

CountyTrap Name22-Jun29-Jun6-Jul
BlairCurryville, PA (Blair)nullnull16
BlairTyrone, PA (Blair)51nullnull
BradfordBristol's Produce000
BradfordLarue's Produce02null
BradfordShores Sisters Produce000
BucksBedminster000
BucksBuckinghamnullnull6
CentreHarner2.3null0
CentreRock Springs2null1
CentreStormstown40.3null9.1
ClintonLoganton000
FayetteDuda's Farm Inc.1520null
HuntingdonNew Morning Farmnull14.8null
IndianaBrush Valleynullnull1
IndianaCreekside2642
LackawannaRansomnull04
LancasterLandisville093
LancasterNeffsville690
LancasterNew Danville572
LehighGermansville4.72224
LuzerneDrums003
LycomingLinden201.8
LycomingMontoursville201442
LycomingMuncy22.6null
MontourMontournull86
NorthamptonNazareth010
SchuylkillTower City101
WashingtonVenetia473516
WestmorelandSchramms Farms and Orchardnull27.1null
YorkYork3288

European corn borer (ECB)

Moth counts have declined to below threshold. Larvae generated from adults earlier in the season can be controlled with a spray timed at row tasel.

CountyTrap Name22-Jun29-Jun6-Jul
BlairCurryville, PA (Blair)nullnull0
BlairTyrone, PA (Blair)0nullnull
BradfordBristol's Produce55224
BradfordLarue's Produce250.398null
BradfordShores Sisters Produce431713
BucksBedminster000
BucksBuckinghamnullnull8
CentreHarner12.3null0.7
CentreRock Springs0null0
CentreStormstownnullnull0
ClintonLoganton182.81.2
FayetteDuda's Farm Inc.00null
HuntingdonNew Morning Farmnull2.3null
IndianaCreekside000
LackawannaRansomnull73
LancasterLandisville2101
LancasterNeffsville480
LancasterNew Danville101
LehighGermansville11.7210
LuzerneDrums1700
MontourMontour1143
NorthamptonNazareth1620
SchuylkillTower City110
WestmorelandSchramms Farms and Orchardnull12.6null
YorkYork008

Fall armyworm (FAW)

We are starting to see low rates of trap capture. Some may be due to a nontarget (Leucania phragmatidicola) but early immigration may also be occurring now. It is not uncommon to find damage prior to trap capture at this time of year. Check for larval feeding in vegetative corn: large, ragged damage to leaves with lots of frass.

Although CEW declined in most locations, captures increased in Lycoming County, and have been about thresholds in much of the state in the last 2 weeks. ECB adult flight has decreased, but larval infestations may be present from earlier flight. We are also beginning to see FAW in the state, which will typically move first into vegetative corn at this time of year. Silking corn will be very attractive to early-season CEW moths.

Average weekly catch--a moving average for the last 7 days. The average catch per night (catch, divided by the number of nights trapping), divided by the number of nights where data exist, multiplied by 7. Weeks where all the average-catch-per-night values are nulls are treated as if no data exist for that week.

PestWatch website

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

Instructors

Insect population dynamics IPM

More by Shelby Fleischer, Ph.D.