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Weekly Field Crops Pest Report 2012

August 10, 2012, Volume 11 Number 17

  1. View from the Field
  2. Weather Outlook
  3. Western Bean Cutworm update
  4. Clipboard Checklist
  5. Mark Your Calendars
  6. Contact Information

View from the Field

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While potato leafhopper (PLH) may still be the pest of the week, the word is populations are starting to decline. Fewer reports of PLH over threshold in alfalfa came in than during the week before. At the Cornell Research Farm in Valatie, PLH have dropped dramatically. I found only one per sample (10 sweeps of the net). Scouting in soybean fields in Dutchess County revealed nymphs at very low levels. 

True armyworm still seems to be hanging around, with reports of armyworm activity in areas of western and northern NY. Targets are grass hayfields and mixed grass/legume stands. 

Soybean aphids remain low statewide. Spider mites are still causing damage to soybeans in Western NY and are active in field corn and other crops. In Dutchess County the soybeans look very good with an average of 50 aphids per plant. Substantial numbers of ladybeetles were most likely feeding on the aphids. Japanese beetle has caused minor damage.

Western bean cutworm larvae FOUND! The first larvae of the season were found this week in field corn ears in Attica, NY (Wyoming Cty). 

Diseases are starting to show up in soybeans this week. Downy mildew has been detected in Cayuga and Dutchess counties. We also found several other diseases in Dutchess County fields. I think we found bacterial blight, bacterial pustule, septoria leaf sport, frog eye leaf spot and cercospora leaf blight.

Stable flies are the dairy pest of the week. These biting flies attack animal’s legs. They lay eggs in moist decomposing materials like hay, manure and straw. They hatch into a maggot and then in about 20 days becomea an adult. If you see animals stomping their legs, it’s a good chance stable flies are biting.

Weather Outlook

August 9, 2012
Andrew Montreuil, Northeast Region Climate Center, Cornell University

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Temperatures last week were generally 3-6º above normal statewide. Precipitation was variable, depending on where thunderstorms produced heavy rain. Generally, areas in the Finger Lakes, Catskills, Mohawk Valley and North Country saw less than 1 inch. Western New York, the St. Lawrence Seaway and the Adirondacks, however, saw over an inch. Base 50 Growing Degree Days were 150-175 statewide, except for the higher elevations of the Adirondacks, Catskills and Allegheny Plateau, where there were 125-150.

The next few days will be dominated by an upper level low stalled out over the Great Lakes. Waves of energy will spin around this low, bringing a chance for significant rain to the state. On Friday widespread thunderstorms are likely, with some strong storms across the Southern Tier and southeast New York. Most areas should see rain. Highs will be in the upper 70s to mid 80s, dependent on morning sunshine. Areas that see morning sun are more likely to reach the mid 80s, while areas with clouds should remain in the 70s. For Saturday, morning lows will be in the low 60s. A few showers or thunderstorms are possible, but most areas should stay dry. Highs will be in the mid to upper 70s, with some locations reaching 80. On Sunday, the low over the Great Lakes will begin to depart. A couple showers are possible, especially over northern New York. Morning lows will be in the upper 50s to low 60s, with highs in the upper 70s to near 80. A few showers or storms are possible for Monday afternoon, but most areas will likely stay dry. Morning lows will be in the upper 50s to low 60s, with highs in the low to mid 80s. On Tuesday, a new but weakening system will come into the state. Some scattered showers and thunderstorms are possible. Morning lows will be in the low to mid 60s, with highs in the mid to upper 80s. Wednesday morning will also have morning lows in the low to mid 60s and highs in the mid to upper 80s. Most areas will be dry, but a couple showers or storms cannot be ruled out.

Expected rainfall over the next 5 days should be near or over an inch for most areas in the state. Higher amounts, possibly near 2 inches, are possible across western New York and the St. Lawrence Seaway, as well as in any heavier thunderstorms Thursday and Friday. The 8-14 day outlook calls for above normal temperatures to near or slightly above normal precipitation.

Maps of 8-14 day outlooks:

National Weather Service Climate Prediction Service Maps of 8-14 day outlooks

National Weather Service Eastern Region Headquarters watch/warnings map

NRCC Drought Page which features the US Drought Monitor map (updated every Thursday)

Western Bean Cutworm update

Keith Waldron

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Western Bean Cutworm captures continued to drop off again this week. As of this writing, a total of 241 WBC moths were caught in the 43 traps reporting this week, down from 909 WBC moths caught in 62 traps last week. Trap catches ranged from 0 to 35. The majority of our NY trap catch numbers are relatively low and do not indicate any cause for concern. Interestingly, 13 traps have caught less than a total 10 WBC moths so far this season. High counts this week came from: Jefferson (34) and Wyoming (35).

Average number of western bean cutworm moths captured per trap.

western bean cutworm chart

WBC egg masses were again collected in Franklin county this week. See photo below. WBC egg masses are laid on the upper surface of corn leaves close to the tassel while the tassel is still in the whorl. New eggs are white and turn purple 1-2 days before hatching. Eggs hatch in 5-7 days.

western bean cutworm egg mass ready to hatch
Western bean cutworm eggs ready to hatch. Note: striated pattern on eggs. Photo by Richard L. Gast, Franklin County CCE.

Corn fields adjacent to Attica NY dry bean field location in Wyoming county were checked this week for egg masses, none were found. However, several 1-2 instar western bean cutworm larvae were found. Multiple larvae may be found per ear. Very young WBC have very distinct spots, their true legs are black, and they loop when they walk.

young larvae of western bean cutworm
Very young western bean cutworm on tassel. Photos by Dr. Chris. Difonzo, Michigan State University.

2nd and 3rd instar WBC larvae look like armyworms. Dr. Difonzo states that: "middle aged WBC larvae look like true armyworm without the bands on their prolegs. WBC larvae have a gap between their true legs at the front and the prolegs (chubby back legs). This gap causes them to walk like an inch worm.”

western bean cutworm larva

western bean cutworm larva2
Western Bean Cutworm 3-4th instar larvae look similar to armyworm larvae. Photos by Dr. Chris. Difonzo, Michigan State University.

In the weeks ahead be on the lookout for signs of WBC larval feeding in corn ears. WBC infested ears may contain more than one larva. Larvae may enter through the silk channel at the ear tip or can bore through the husk or ear shank.  Excessive bird activity and damage may indicate insect larvae are in the ears. Damage caused by larval feeding can open ears up to potential risk of ear molds.

Accumulated western bean cutworm moths per location as of 8.10.12

County City Total WBC County City Total WBC
Broome Whitney Point 0 Livingston Caledonia 26
Cattaraugus Olean 16 Livingston Lima 44
Cayuga King Ferry 1 Madison Kirkville 34
Cayuga Aurora 27 Monroe Hamlin 44
Cayuga Franklin St 56 Monroe Spencerport 23
Chautauqua Kennedy 107 Monroe Churchville 27
Chenango Sherburne 19 Niagara Lockport 21
Chenango Afton 14 Oneida Clinton 20
Clinton Clinton 30 Oneida Clinton 18
Clinton Chazy 22 Onondaga Baldwinsville 5
Cortland Preble 77 Onondaga Tully 16
Cortland Marathon 2 Ontario Farmington 2
Delaware Oneonta 19 Ontario Geneva 44
Delaware Walton 34 Ontario Hopewell 3
Dutchess Millbrook 39 Ontario Ontario 25
Erie Eden Z 105 Orleans Waterport 20
Essex Essex 12 Otsego Garrattsville 13
Essex Willsboro 12 Schoharie Middleburg 22
Franklin Malone 132 Schuyler Burdett 1
Genesee Batavia 30 Schuyler Valois 9
Genesee Leroy 33 St.Lawrence Madrid 284
Genesee Batavia 15 Steuben Avoca 16
Genesee Stafford 15 Steuben Wayland 28
Genesee Alexander 17 Suffolk Riverhead 1
Genesee Stafford 82 Tioga Owego 6
Green   27 Tioga Owego 1
Herkimer Little Falls 47 Tompkins Varna 27
Jefferson Ellisburg 189 Washington   6
Jefferson Sacketts Harbor 328 Wayne Williamson 24
Jefferson Plessis 39 Wayne Wayne 13
Lewis Martinsburg 279 Wyoming Attica 258
Livingston Avon 44 Yates Bellona 23
Livingston Cuylerville 7 Yates PennYan 28


More WBC monitoring information is available at:
Western Bean Cutworm identification card – including larval stages.

Cornell Sweet Corn Monitoring Network

Penn State Pest Watch (Includes WBC data from NY, New England and other states)

Ontario WBC Trap Network
Cornell Field Crop Extension Homepage: “field” "blog" section. 

Western Bean Cutworm - Corn scouting videos:

The NY WBC trapping program will continue through August.

Clipboard Checklist

Keith Waldron

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* Emergency contact information ("911", local hospital, Chem. Spill emergency contact, other?) posted in central posting area
* Maintain crop records by field, including variety, planting date, pesticides used, nutrient inputs including manure, etc.
* Watch for any patches of herbicide resistant weeds, weed escapes
* Storage areas cleaned and ready to accept hay, wheat harvest

* Monitor fields for plant vigor, growth stage, vegetative stage pest issues (corn rootworm, European corn borer, spider mites, armyworm, foliar diseases, western bean cutworm larvae in ears, nutritional deficiencies)
* Monitor for weeds, note presence of "who", "how many" and "where"

Small Grains:
* Evaluate crop for maturity, lodging, time till harvest
* Grain bins ready to accept upcoming harvest?

Alfalfa & Hay:
* Monitor alfalfa seedings for weeds, insects & diseases.
* Check re-growth of established alfalfa stands for potato leafhopper, weed and disease problems.
* Monitor grass hay fields for armyworm

* Evaluate stand growth, development and condition
* Monitor fields for soybean aphid, foliar diseases, white mold, natural enemies, weed escapes, spider mites

Dairy Livestock Barn Fly Management:
* Sanitation, sanitation, sanitation - clean animal resting areas, feed troughs, minimize source of moist organic matter i.e. fly breeding areas in barn and in adjacent animal loafing yard
* Check water sources, drainage, roof gutters for leaks and potential overspill
* Continue fly monitoring: install "3X5" index card fly speck monitoring cards throughout barn
* Install/refresh/replenish as needed: fly tapes, insecticide baits, natural enemies (parasitoids

Dairy Livestock Pasture Fly Management:
* Monitor animals for presence of pasture fly pests. Treatment guidelines: Horn flies (50 per dairy animal side, 100 per side for beef cattle), face flies (10 per animal face), stable flies (10 per 4 legs). See: (
* Consider installing biting fly traps to reduce horse, deer and stable fly populations.

* Check storage areas (bunk silos, etc.) for readiness to accept upcoming wheat harvest
* Clean in and outside of storage bins and grain handling equipment
* Keep areas around storage bins and silos clean and mowed
* Check areas around storage bins and silos for vertebrate tunneling
* Check temperature of recently baled hay in hay mow

* Note any repairs needed for recently used equipment: tractors, tillage implements, planters, sprayers, etc. as they are cleaned and serviced.
* Service hay harvesting equipment as needed.
* Calibrate manure spreaders - maintain records on amount spread per field

Emergency responder information on pesticide spills and accidents…
CHEMTREC - 800-424-9300

For pesticide information
National Pesticide Information Center: 800-858-7378

To Report Oil and Hazardous Material Spills in New York State
NYS Department of Environmental Conservation Spill Response - 800-457-7362 (in NYS), 518-457-7362 (outside NYS)

Poison Control Centers
Poison Control Centers nationwide -  800-222-1222

If you are unable to reach a Poison Control Center or obtain the information your doctor needs, the office of the NYS Pesticide Coordinator at Cornell University, 607-255-1866, may be able to assist you in obtaining such information.

Mark Your Calendars

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2012 New York Corn and Soybean Grower Summer Crop Tour, August 14, 2012, Dumond Farm, Union Springs, NY, 8:30 – 4:30 pm.

Contact Information

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Keith Waldron: NYS Livestock and Field Crops IPM Coordinator
Phone: (315) 787 - 2432
Fax: (315) 787-2360

Ken Wise: Eastern NYS IPM Area Educator: Field Crops and Livestock
Phone: (518) 434-1690
Fax: (518) 426-3316