[xml] [original]

Header

Title

PestWatch Report: June 29, 2022

Authors

Authors

Availability

Better title

PestWatch Report: June 29, 2022

Source

Penn State Extension (psu.edu)

URL

https://extension.psu.edu/pestwatch-report-june-29-2022

Date

2022-06-29

Description

Abstract

Corn earworm moth catch is steady throughout Pennsylvania.

Keywords

tags = Penn State Extension, Agriculture, Dairy, Beef, Crops, Food Safety, Nutrition, Business Management, Natural Gas, Renewable Energy, Forest Management, Water, Cooperative Extension, University Park, Pennsylvania

Body

Corn earworm larvae. Photo: Frank Peairs, Colorado State University, Bugwood.org

There was not much increase in corn earworm numbers this week and some sites even caught fewer than last week. Sites in Franklin and Mifflin counties are experiencing catches per night of 6–7 moths per night which means a spray interval of 4–5 days would be suggested for corn that’s tasseling or silking in those areas. As a reminder, corn that is tasseling or silking is very attractive to corn earworm, as eggs are laid on silks. Control must be achieved while larvae are recently hatched and before they’ve entered the ear.

Once the spray threshold is reached, you can consider products from the pyrethroid class, diamide class, or spinosyn class for effective control. We tend to see the best efficacy from non-pyrethroid products such as Coragen, Blackhawk, and Radiant, as pyrethroid resistance has increased in migrating corn earworm populations. However, we tend to see more resistance later in the season than now, as moths migrate from further south in the United States up to our region. Diamides and spinosyns do not provide effective control of other pests such as sap beetles, brown marmorated stink bug, Japanese beetles, or adult corn rootworms. If you’re seeing these pests as you scout your corn, consider adding a pyrethroid, or the premix Besiege to control those.

We’re still seeing very few fall armyworm caught for this season in Pennsylvania, though one site in Lycoming County averaged 0.8 moths caught per night this week. By managing for corn earworm, fall armyworm should be adequately controlled, as well.

Average weekly catch – 7-day moving average. The average catch per night (total catch, divided by the number of nights trapping), divided by the number of nights where data exist, multiplied by 7. If no data exist for that week, null is reported.

CEW CEW CEW FAW FAW FAW
County Site 13-Jun 21-Jun 27-Jun 13-Jun 21-Jun 27-Jun
Blair Curryville 1.7 7 0.9 0 0 0
Blair Sinking Valley 0.9 2.1 2.9 0 0 0
Bucks Doylestown 0 0.6 0.4 0 0 0
Centre Harner 0.3 2 6 0 0 0
Centre Rock Springs 0.7 2.8 2.8 0 0 0
Clinton Kaufman Null 0.3 0.3 Null 0 0
Franklin Shippensburg 0.3 9.1 7 Null 0.1 0
Franklin Waynesboro 8 8.7 5 0 0 0
Indiana Indiana Null 2.7 0.5 Null 0 0
Lancaster Landisville 0.1 0.7 0.4 0 Null 0
Lancaster New Danville 0 0.6 0.1 0 Null 0
Lancaster Neffsville Null 0.4 0.6 Null Null 0
Lehigh Germansville Null 5.8 Null Null 0 Null
Lycoming Linden Null Null 2 Null Null 0
Lycoming Montoursville Null Null 0.9 Null Null 0.9
Mifflin Streamside Null 7.1 6 Null 0 0
Washington Bebout Null 5.4 2.3 Null Null 0
York York 0.3 0 1 0 0 0

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

Threshold based on CEW Catch per week Spray Frequency
Almost Absent 1–13 7+
Very low 14–35 5–6
Low 36–70 4–5
Moderate 71–349 3–4
High >350 2–3