Purdue Cooperative Extension Service
Issue 4, April 21, 2017 • USDA-NIFA Extension IPM Grant
This spring continues to shape up as a year with heavy armyworm pressure. With relatively little corn planted so far this isn’t time to panic – but we typically don’t see levels this high at this time of year, so if you have never scouted for armyworms before, this would be a good year to start! You’ll probably find some.
The northeastern part of the state, where we happen to also grow wheat (armyworms love wheat) in some areas, is particularly thick with migrant moths. The female moths that arrive will be loaded with eggs and looking for suitable hosts to lay them on – many plants will do the job, with grasses strongly preferred. If you have wheat acreage, or your soon-to-be-corn acres have a grass cover crop, particularly cereal rye, those fields will be an armyworm magnet. Depending on when that cover crop is killed and corn is planted, the crop could be at risk.
The level of risk depends on two main factors: 1) the level of armyworm pressure in the area (see Table below - this will be high in much of the state this year), and 2) the degree of overlap between the grass host and emerging corn. That might also be high this year. As stated last week, a period without green, growing material will readily starve most armyworms. When that’s not possible, it’s time to reach for the insecticides to hit the larvae before they can feed on emerging corn. There are many insecticide options Corn Insect Control Recommendations - E-219, but all will work best when larvae are small (less than 1¼”in length).
Scouting fields beginning late next week is advised… before then, the larvae will be too small to see easily. By early May, larvae should be quite conspicuous and scouting will be relatively easy. A sweep net can be used, or even just visually inspecting plants for damage and/or feeding larvae will work. Disturbing and poking through the top layer of soil will reveal the larvae during sunny days, when they often rest here. Although there is not a threshold for armyworm in cover crops, 4 larvae/sq. ft is the guideline in wheat. Remember, Bt corn and seed treatments won’t save you from this one. So venture out late next week and check those high-risk fields.
County/Cooperator | Wk 1 | Wk 2 | Wk 3 | Wk 4 | Wk 5 | Wk 6 | Wk 7 | Wk 8 | Wk 9 | Wk 10 | Wk 11 | Wk 12 |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Dubois/SIPAC Ag Center | 0 | 0 | 0 | 101 | 193 | |||||||
Jennings/SEPAC Ag Center | 0 | 1 | 1 | 56 | 57 | |||||||
Knox/SWPAC Ag Center | 0 | 13 | 26 | 42 | 189 | |||||||
LaPorte/Pinney Ag Center | 0 | 0 | 3 | 352 | 936 | |||||||
Lawrence/Feldun Ag Center | 4 | 108 | 216 | 246 | 650 | |||||||
Randolph/Davis Ag Center | 0 | 29 | 41 | 528 | 1232 | |||||||
Tippecanoe/Meigs | 0 | 2 | 15 | 107 | 730 | |||||||
Whitley/NEPAC Ag Center | 0 | 34 | 90 | 537 | 1689 |
Wk 1 = 3/16/17 - 3/22/17; Wk 2 = 3/23/17 - 3/29/17; Wk 3 - 3/30/17 - 4/5/17; Wk 4 - 4/7/18 - 4/12/17; Wk 5 - 4/13/17 - 4/19/17
County | Cooperator | BCW Trapped | ||||
---|---|---|---|---|---|---|
Week 1
|
Week 2 3/30/17-4/5/17 |
Week 3 4/5/17-4/12/17 | Week 5 - 4/13/17 - 4/19/17 | |||
Adams | Kaminsky/New Era Ag | 13 | 35 | |||
Adams | Roe/Mercer Landmark | 11 | 17* | 7 | 42 | |
Allen | Anderson/Syngenta Seed | 0 | ||||
Allen | Gynn/Southwind Farms | 2 | 1 | 0 | 15 | |
Allen | Kneubuhler/G&K Concepts - Trap 1 | 0 | 19* | 36 | ||
Allen | Kneubuhler/G&K Concepts - Trap 2 | 9 | 2 | |||
Bartholomew | Bush/Pioneer Hybrids | 1 | 13* | 13 | 17 | |
Clay | Bower/Ceres Solutions - Clay City | 0 | 0 | 7 | 4 | |
Clay | Bower/Ceres Solutions - Bowling Green | 0 | 0 | 0 | ||
Clay | Bower/Ceres Solutions - Brazil | 0 | 0 | 0 | ||
Clinton | Emanuel/Boone Co. CES | 8 | 9 | 6 | 10 | |
DeKalb | Hoffman/ATA Solutions | 0 | 0 | 0 | 1 | |
Dubois | Eck/Purdue CES | 14 | 28* | 41* | 4 | |
Elkhart | Kauffman/Crop Tech Inc. | 0 | 0 | 6 | 16 | |
Fayette | Schelle/Falmouth Farm Supply Inc. | 5 | 33* | 5 | ||
Fountain | Mroczkiewicz/Syngenta | 7 | 18* | 31* | 93* | |
Fulton | Jenkins/N. Central Coop - Talma | 0 | 5 | 10 | 13 | |
Fulton | Ranstead/NCC Coop - Rochester | 0 | 0 | 0 | 3 | |
Gibson | Schmitz/Gibson Co. CES | 0 | ||||
Hamilton | Campbell/Beck's Hybrids | 14 | 13 | 18 | 55* | |
Hamilton | Truster/Reynolds Farm Equipment | 1 | 1 | |||
Hendricks | Nicholson/Nicholson Consulting | 0 | 3 | 4 | 11 | |
Jasper | Overstreet/Jasper Purdue CES | 2 | 5 | 0 | 5 | |
Jasper | Ritter/Brodbeck Seeds | 1 | 3 | 10 | 32 | |
Jay | Boyer/Davis PAC | 3 | 14 | 19 | ||
Jay | Shrack/Ran-Del Agri Services | 1 | 3 | 5 | 9 | |
Jay | Temple/Jay County CES | |||||
Jennings | Bauerle/SEPAC | 0 | 0 | 0 | 0 | |
Knox | Bower/Ceres Solutions - Freelandville | 0 | 0 | 0 | 13* | |
Knox | Bower/Ceres Solutions - Vincennes | 0 | 0 | 0 | ||
Kosciusko | Klotz/Etna Green | 0 | 0 | 4 | 9 | |
Lake | Kleine/Kleine Farms | 4 | 16* | 60* | 83* | |
Lake | Moyer/Dekalb Hybrids - Shelby | 5 | 5 | 20* | 27 | |
Lake | Moyer/Dekalb Hybrids - Schneider | 2 | 5 | 5 | 12 | |
LaPorte | Rocke/Agri-Mgmt Solutions | 4 | 41 | |||
Madison | Truster/Reynolds Farm Equipment | 0 | ||||
Marshall | Harrell/Harrell Ag Services | 0 | ||||
Marshall | Klotz/SR 10 & SR 331 | 0 | 0 | 0 | 8 | |
Marshall | Miller/North Central Coop | 0 | 0 | 0 | 2 | |
Miami | Early/Pioneer Hybrids | 0 | 0 | 0 | ||
Newton | Moyer/Dekalb Hybrids - Lake Village | 2 | 6 | 2 | 8 | |
Porter | Leuck/PPAC | 5 | 3 | 18 | 25 | |
Pulaski | Capouch/M&R Ag Services | 0 | 0 | 1 | 10 | |
Pulaski | Leman/North Central Coop | 0 | 10 | 21 | ||
Putnam | Nicholson/Nicholson Consulting | 2 | 6 | 2 | ||
Randolph | Boyer/DPAC | 1 | 0 | 1 | ||
Rush | Schelle/Falmouth Farm Supply Inc. | 6 | 10 | 1 | ||
Shelby | Fisher/Shelby County Co-op | 2 | 3 | 5 | 5 | |
Shelby | Simpson/Simpson Farms | 7 | 49* | 41* | 67* | |
Starke | Capouch/M&R Ag Services | 0 | 0 | 6 | 28 | |
Starke | Wickert/Wickert Consulting - California Twnshp | 1 | 1 | 3 | 4 | |
Starke | Wickert/Wickert Consulting - Railroad Twnshp | 0 | 0 | 0 | 0 | |
St. Joseph | Barry/Helena | 1 | 3 | |||
Sullivan | Bower/Ceres Solutions - Farmersburg | 0 | 1 | 2 | 14 | |
Sullivan | Bower/Ceres Solutions - Sullivan | 6 | 21* | 14* | 16* | |
Tippecanoe | Bower/Ceres Solutions | 0 | 0 | 0 | 7 | |
Tippecanoe | Kremer/Monsanto Research Farm | 0 | 0 | 13 | 11 | |
Tippecanoe | Nagel/Ceres Solutions | 30 | 47* | 44* | 89 | |
Tippecanoe | Obermeyer/Purdue Entomology | 2 | 5 | 11 | 5 | |
Tipton | Campbell/Beck's Hybrids | 10 | 17 | 11 | 73* | |
Vermillion | Bower/Ceres Solutions | 0 | 0 | |||
Wabash | Enyeart/North Central Coop | 0 | ||||
Whitley | Walker, Richards/NEPAC1 - Main | 10 | 28* | 37* | 81* | |
Whitley | Walker, Richards/NEPAC2 - Kyler | 3 | 8 | 17* | 36* |
* = Intensive Capture...this occurs when 9 or more moths are caught over a 2-night period
Purdue Extension Entomology
901 W. State Street
West Lafayette, IN, 47907
(765) 494-8761
luck@purdue.edu
@PurdueExtEnt
PurdueEntomology
If you would like to be alerted by e-mail when the current issue of the Pest&Crop is available on-line, please enter your e-mail address and click the submit button.
It is the policy of the Purdue University Cooperative Extension Service that all persons have equal opportunity and access to its educational programs, services, activities, and facilities without regard to race, religion, color, sex, age, national origin or ancestry, marital status, parental status, sexual orientation, disability or status as a veteran. Purdue University is an Affirmative Action institution. This material may be available in alternative formats.