Corn Earworm Trap Network Summary 2025
Early, heavy corn earworm moth
flights in July prompted Wisconsin sweet corn growers to begin management
programs about a month ahead of the usual mid-August schedule. Moths started
arriving in the state June 30 to July 3, when monitoring sites in Dane, Dodge,
and Rock counties registered incoming flights of 100 to 276 moths per week.
Migration flights leveled off in July but surged during the second and third
weeks of August before waning in September.
DATCP’s pheromone trap network collected a
cumulative total of 12,435 corn earworm
moths in 12 traps this season (1,036 moths per trap average), with the largest flights recorded
August 15 to 21. Flights peaked at 189 moths per night near Burlington in
Walworth County, 159 moths per night at Beaver Dam in Dodge County, 97 moths
per night at Clinton in Rock County in this timeframe. The trap location with
the highest cumulative catch was Burlington in Walworth County, where 2,417
moths, or one-quarter of the 2025 total moth catch, were collected.
This year’s moth count was 41% higher than the 8,849 moths collected in 14
traps in 2024 (632 moths per trap average), though comparable to the 13,996
moths collected in 12 traps in 2023 (1,166 moths per trap average). The
protracted migration posed a mid- and late-summer threat to fresh market and
processing sweet corn. Corn earworm larvae were unusually prevalent by
September and were observed in 30% of the grain corn fields sampled as part of
the fall corn pest survey, well above the 9% rate recorded last season.
Moth Counts for the 2025 Season
|
County |
Location |
Wk 1 |
Wk 2 |
Wk 3 |
Wk 4 |
Wk 5 |
Wk 6 |
Wk 7 |
Wk 8 |
Wk 9 |
Wk 10 |
Wk 11 |
Wk 12 |
Columbia
| Pardeeville
|
| 4
| 2
| 1
| 0
| 0
| 178
| 126
| 7
| 1
| 0
| 2
|
Dane
| Sun Prairie E
|
| 168
| 11
| 0
| 2
| 2
| 328
| 400
| 216
| | 39
| |
Dane
| Sun Prairie N
|
| 227
| 29
| 0
| 0
| 0
| 284
| 500
| 213
| | 33
| |
Dodge
| Beaver Dam
|
| 9
| | | | 1
| 718
| 1112
| 79
| 78
| 77
| 126
|
Dodge
| Mayville
|
| | 252
| 8
| 8
| 1
| 294
| 429
| 70
| 2
| 1
| |
Dodge
| Watertown
|
| 123
| 23
| 0
| 0
| 2
| 314
| 300
| 70
| | 9
| |
| Marathon | Wausau
|
| 0
| 0
| 0
| 1
| 0
| 2
| 1
| 0
| 0
| 0
| 0
|
Rock
| Clinton
| 276
| 201
| 37
| 7
| 5
| 6
| 615
| 679
| 220
| 46
| 11
| 13
|
Vernon
| Coon Valley
| | 0
| 15
| 0
| 4
| 1
| 305
| 371
| 110
| 20
| 0 | 5
|
Walworth
| Burlington
|
| | 17
| 2
| 0
| 17
| 524
| 1325
| 420
| 32
| 28 | 52
|
Waushara
| Hancock
| | 14
| 1
| 0
| 2
| 0
| 60
| 90
| 8
| 0
| 3
| |
Wood
| Marshfield |
| 10
| 0
| 0
| 0
| 0
| 0
| 0
| 0
| 0
| 0
| |
Week 1 (Jun 30-Jul 03), Week 2
(Jul 04-10), Week 3 (Jul 11-17), Week 4 (Jul 18-24), Week 5 (Jul 25-31), Week 6 (Aug 01-07), Week 7 (Aug 08-14), Week 8 (Aug 15-21), Week 9 (Aug 22-28), Week 10 (Aug 29-Sep 4), Week 12 (Sep 5-11), Week 13 (Sep 12-18).