PestWatch Report for August 28, 2019

 

Sites where sprays are applied may reduce counts, and moving traps close to silking corn will increase the catch. Within the last two weeks, sites exceeding 70 moths/week, suggesting a tight (3-4) day spray interval occurred in Bucks, Centre, Lancaster, Mifflin, Northampton, Schuylkill, and Union counties. Sites with 36-70 moths/week, suggesting a 4-5 day interval, were reported in Blair, Erie, Juniata, Lancaster, Lycoming, and York counties. Additional sites had lower counts but still above a spray threshold. Only 3 of 32 sites stayed below the threshold.

 

Populations carrying pyrethroid resistance tends to in-crease in August. Non-pyrethroid options include Coragen, Blackhawk, and Radiant. However, these will not control sap beetles, BMSB, or insects feeding on silk (Japanese beetles, adult corn rootworms). Adding a pyrethroid, or the premix Besiege, should help with pests that are not “worm” species.

 

European corn borer (ECB) counts are low. Sprays targeting Corn earworm (CEW) will control ECB.

 

Fall armyworm (FAW) captures are spiking in Erie county, and also rose dramatically in central PA (Blair, Butler, Centre, and Union counties). A non-target called Intermediate Cucullia, or Intermediate Hooded Owlet, is also showing up in the FAW traps.

 

 

Average weekly catch –7-day moving average. The average catch per night (catch, divided by the number of nights trap-ping), 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.

 

 

Thresholds: Reproductive (tassel/silk) and late vegetative corn attracts moths. Shorten spray schedules when populations increase. If CEW is not a problem, then consider ECB.