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Weekly Field Crops Pest Report 2010

August 16, 2010             Volume 9 Number 16

1. View from the Field

2. Weather Outlook August 12, 2010

3. Fly Traps for Biting Flies Attacking Animals on Pasture

4. Certified seed and fungicide seed treatment are good insurance for winter wheat

5. Are soybeans at risk from spider mites?

6. Check For Stalk Rots!

7. Western Bean Cutworm - Where are they now?

8. Clipboard Checklist

9. Contact Information

View from the Field

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This week last week (Aug 11) Mohammad S. A. Faroze extension educator and Les Hulcoop retired extension educator in Dutchess County had a field meeting where we discussed field corn, alfalfa and soybean IPM. There were 2 pest issues that arose in the meeting. Potato leafhopper levels were over threshold in alfalfa and one of the growers had sprayed for spider mites on soybeans.  We also had a long discussion on proper use of fungicides in soybeans and corn. Stephen Canner (St. Lawrence county CCE) had a soybean IPM field meeting on (Aug. 12). Downy mildew was found on all of the soybean plants. Only the new growth did not show signs of the disease.

Western bean cutworm (WBC) moth captures are down from last week, indicating peak flights have occurred. The first reports of WBC larvae feeding came in 8/13/10 from Lewis county. Joe Lawrence reports finding several 3/4 inch WBC larvae 90 day field corn at milk stage. Injured plants were difficult to find within the field, however, a very few plants were found showing signs of larval feeding on developing ears.

Weather Outlook August 12, 2010

Jessica Rennells
Northeast Regional Climate Center

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Last week temperatures were 0 to 6 degrees above normal. Precipitation ranged from .01 inches to 2 inches. Though most of the state had half to two inches.

The base 50 Growing Degree Days ranged from 125 to 175. Most of the state is ahead of last year by over three weeks. Compared to normal, the state is ahead by 2 to over 3 weeks.

Today‘s (8/12/10) highs will be in the mid 70’s to mid 80’s.  Tonight’s temperatures will be around 60. Showers and some thunderstorms will occur throughout the day.

Friday will be throughout the 70’s and into the lower 80’s with continued scattered showers and thunderstorms. Friday night will be in the mid 50’s to low 60’s. Saturday’s highs will range throughout the 80’s with a low chance for scattered showers in the morning before high pressure moves in. Lows will be in the mid to upper 60’s. Sunday will have highs in the upper 70’s and low 80’s with showers and thunderstorms likely. Overnight temperatures will be in the mid 60’s to low 70’s. Monday highs will be in the low to mid 80’s with showers  and thunderstorms likely. Lows will be in the mid to upper 60’s.Tuesday’s temperatures will be in the mid 80’s with lows in the low to mid 60’s. There will be a few scattered showers left along eastern NY. Wednesday’s highs will be in the upper 70’s and low 80’s and lows will be in the mid 60’s. There will be another chance for scattered showers.

The five day precipitation amounts will range from a half to one inch. The 8-14 day outlook is showing above average temperatures and precipitation. The southern Hudson Valley and Catskill regions are still abnormally dry.

Fly Traps for Biting Flies Attacking Animals on Pasture

Keith Waldron

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Alsynite Trap
A cylindrical fiberglass sheet reflects light in a way that is particularly attractive to stable flies but will attract house flies also. Sticky translucent fly paper is wrapped around the outside and replaced when saturated with flies.  Place out of reach of animals in a sunny location since they attract flies by visual means. The trap is should be set 1 to 2 feet above the ground and placed about 10 feet from building walls or on pastures in those areas where the animals will be concentrating, such as near water sources.

Horse Pal
This trap is specifically designed to attract and catch horse, deer, and stable flies by mimicking the underside of a cow. Flies land on the surface of a swaying dark sphere, migrate up toward the light in the screened area, and are ultimately trapped in the jar on top. The collection jar is removed periodically and emptied. Begin by placing 1 to 2 traps in the field and increase as necessary. Traps should be placed near, but out of reach of curious animals to prevent damage.

Epps Trap
Biting flies, such as stable, horse, and deer flies, are attracted to the large shape of the Epps Trap made to resemble a cow. Biting flies tend to circle their host before landing for a meal and perceive the clear plastic spaces of the trap as open space under the animal. They fly into the clear plastic and ricochet into trays of liquid where they drown. Maintain the trap by skimming dead insects from the liquid and replacing the liquid when fouled. Mow weeds beneath the trap to preserve the contrast between light areas and dark. Traps work best placed in a sunny part of the pasture near historic fly problem areas. Use one trap per 20 acres of pasture, or place in a sunlit spot outside stables. Placing the trap out of reach from curious livestock is highly recommended.

Information on pasture fly management including pictures of various fly traps can be found in our publication Integrated Pest Management Guide for Organic Dairies For more information see: Pest Flies of Pastured Cattle and Horses

Certified seed and fungicide seed treatment are good insurance for winter wheat

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Soilborne fungal disease occurrence on roots, stems, and crowns of winter wheat is generally not severe when wheat growers rotate with non-cereal crops. However, low levels of soilborne and seedborne fungal diseases can cause problems with stand establishment. A stand that is not well established in the fall will have a harder time making it through the winter, and may not be as quick to green up in the spring.

Seedling disease threats can largely be prevented with the use of fungicide-treated seed. These threats include the smut diseases that may be present on the surface of the seed or deep inside the embryo of the seed. Also, several soil-dwelling disease agents can cause plant roots and/or crowns to rot before the plant becomes established. In addition, seed fungicide treatments can aid in the suppression of early foliar diseases such as powdery mildew in the fall.

Fungicide-treated seed is widely available commercially, or treatments of fungicides can be made on-farm. The most effective treatments combine a systemic fungicide and a protectant fungicide. For specific reference to chemicals, please visit the Cornell Guide for Integrated Field Crop Management.

Another key tactic for good stand establishment is to plant certified seed. Use of certified seed assures a grower that seed meets high state and national standards for purity, identity, and freedom from noxious weed seeds and seedborne diseases.

Are soybeans at risk from spider mites?

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Many of the areas of the state have been experiencing dry weather conditions. Hot weather combined with dry - droughty conditions can increase risk of spider mites becoming a problem in soybeans and field corn. Two-spotted spider mites are tiny, oval, 8-legged, pale-bodied arachnids. The feeding of spider mites causes a stippling of leaves. Severe feeding by many mites causes a bronzing of the leaf. The injury from spider mite feeding can resemble a foliar fungal disease infection. Another identifying factor of spider mites is the silk-like webbing they produce. The webbing can be seen on leaflets and petioles in a heavily infested field. The mites are able to use the silk as a means to hold on to while being transported by wind to un-infested areas of a field. When scouting, to help to confirm the presence of spider mites, hold a white piece of paper under a plant. Tap on the plant, and some of the mites should fall to the paper. They are small, so may appear as yellow or yellow brown moving specs.

Spider mites on soybean
Early symptoms of spider mite injury on the upper leaf surface

Spider mite populations can increase extremely rapidly - they can develop from egg to adult in 5 days with high temperatures.  Cool, damp weather often leads to steep declines in spider mite populations by encouraging fungal pathogens to take control.

Spider mites are regular residents of weedy areas at field edges.  During dry weather, if these weed hosts become stressed, spider mites may begin to move into the nearby crop. Thus, an infestation usually begins at field edges and radiates into the field.  While a spot-treatment with an insecticide may be helpful to combat the start of a severe infestation, it is critical to scout the whole field.  Low numbers of spider mites can be present before the injury can be seen from a distance.  When chemical control is chosen for spider mite management, it is critical to bear in mind the risks of "flare-ups" from use of pyrethroid insecticides.

Check For Stalk Rots!

Ken Wise

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It is important to monitor your fields for stalk rots as you start thinking of your corn harvest. If you have an infection of stalk rot it can cause the plant to die early losing grain or silage yields. Stalk rots are caused by many different fungi that enter the plant. They occur when the plant is under stress or when it may be injured by insect pests, hail, deer and bird damages, drought or soil saturation, lack of sunlight, extended cool weather, and the lack of fertility. The following are symptoms of specific stalk rots:

Anthracnose stalk rot symptoms may appear after tasselling as vertical, tan to reddish brown, water-soaked lesions (streaks) in the stalk rind. Lesions become large, dark brown to shiny black. Fields with high amounts of anthracnose leaf blight (both diseases have the same causal agent) should be checked for indications of anthracnose stalk rot.

Diplodia stalk rot symptoms may appear as numerous black pycnidia in the lower internodes of the stalk. The black dots are the size of a pinhead or smaller. When conditions are wet a white mold may develop on the stalk surface.

Fusarium stalk rot normally starts just after pollination and symptoms appear later in the season. When you cut open the stalk, the pith appears as a whitish to pink (salmon) color. There are also distinctive brown streaks on the lower internodes.

The first symptom of gibberella stalk rot is the onset of grayish-green color of the leaves. The stalk will turn dark green to tan near the base of the plant. The pith of the stalk becomes soft and will appear as a red to pinkish color.

Pythium stalk rot normally appears as a decay of the first internode above the soil. The pith will become soft, turn brown and appear water-soaked. Many times the stalk can twist and/ or lodge. Even though it may have lodged the plant will stay green for several weeks because the vascular tissue is not destroyed.

If you discover certain stalk rot diseases make notes of the hybrid, tillage methods, rotation history, and planting date. By doing this you be able to avoid the disease occurrence in the future. The following is the effectiveness of specific management practices for stalk rots:

Corn Disease
(Stalk Rots)
Resistant Variety
Crop Rotation
Clean Plow
Down of Residue
All Other
1= highly effective, 2= moderately effective, 3=slightly effective, 4= not effective, 5 = not usually economical,
Reference: Purdue University Field Crops Pest Management Manual

As with most diseases that attack corn, if you can reduce stress on the plants you most likely can reduce the occurrence of certain stalk rots. Having a sound fertility program based on soil testing is important for keeping a corn plant healthy. Select a hybrid with resistance to certain diseases and good standability that is adapted to your region. Some of these stalk rots can produce mycotoxins that can be toxic to livestock. You should consider having silage tested for certain mycotoxins if you had fields with stalk rots this season. For more information on corn diseases checkout our online publication: Diseases of Corn

Western Bean Cutworm - Where are they now?

Keith Waldron

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Western bean cutworm (WBC) is a late season pest of corn and dry beans that was first found in NY last summer in Genesee, Livingston, Niagara, and Wyoming counties. Western bean cutworms are not a pest of soybeans. While WBC's are not expected to cause any economic concern this season our statewide monitoring program objective is to determine the current geographic range and relative activity of this insect across NY this season. WBC traps have been deployed in Cattaraugus, Cayuga, Chautauqua , Chemung, Chenango, Columbia, Cortland, Erie , Genesee , Jefferson , Lewis, Livingston, Madison , Monroe , Montgomery, Niagara , Oneida, Onondaga , Ontario, Orleans , Schoharie, Seneca, Steuben, Suffolk, Tioga, Tompkins, Washington, Wayne , Wyoming , Yates counties this summer.

Our WBC moths are migrants from states west of us. Peak moth flights occurred two weeks ago in Ohio and Ontario. NY western bean cutworm moth catches appeared to slow down this week (8.8.10) and are expected to decline again in weeks to come. Western bean cutworm moths have now been collected in 50 of 57 traps participating in the monitoring network. WBC have not been collected in Chenango, Columbia and Wayne counties. Fewer WBC moths have been collected in eastern NY than in more central and western counties with the highest single week catches occurring in Erie and Livingston counties over the past 2 weeks.

Total NY weekly WBC counts
Range in statewide NY weekly WBC counts per trap

Our total statewide accumulated WBC counts as of August 13, 2010 are 686. By contrast, our NY WBC total is but a fraction of what has been captured to date in Ohio (2,482 as of 8.2.10), Michigan (39,282 as of 7.24.10) and Western Ontario (54,196 as of 8.11.10).

Where are they now? WBC moths are attracted to pre-tassel corn. As corn moves to grain fill stages WBC moths are more attracted to dry beans for egg laying. Western bean cutworm egg masses were detected on sweet corn in Eden valley (Erie county) July 20. WBC larvae hatch in 5-7 days then make their way to tassels and ultimately to corn ears. Larvae can bore through the husks, ear shanks or enter the ear near the silk region. In dry beans, WBC larvae feed on pods and developing beans. Appearance First instar WBC larvae are brown with a black head and markings down their back. Mature larvae can reach 1.5 inches, are smooth, hairless, and light tan to pink. At first glance, WBC larvae are distinguished by two distinctive dark brown stripes immediately behind the head. Unlike other caterpillars that feed on corn ears (corn earworm, European corn borer, Fall armyworm) WBC larvae could have multiple larvae per ear. Yield loss estimates from the Midwest indicate potential losses of 3.7 bu/ac in fields infested with an average of 1 larva per plant. Additional impacts may occur through ear rots and secondary pests associated with feeding injury. We are just learning about this pest in NY and would be very interested in hearing your observations regarding signs of larval feeding. The best photos are available by searching websites on the internet. WBC moths have only one generation per year. Mature WBC larvae will leave corn ears sometime in mid September, drop to the ground and burrow into the soil where they overwinter in a soil chamber as a full-grown larva. Larvae pupate the following year. It is not yet known if WBC will successfully overwinter in NY. In the Midwest, pupation occurs in May and moths begin to emerge in late June. WBC moths were first caught in NY this season the week of June 29th.

WBC monitoring updates are posted in the NYS IPM Weekly Pest Report  and are available on Penn State's Pest Watch. Thanks again to our WBC trap monitoring cooperators. Our trapping network is a joint effort of the Cornell Cooperative Extension, the NYS Integrated Pest Management Program and many participating corn and dry bean producer volunteers. For photos and more information on Western Bean Cutworm see the University of Illinois' factsheet on Western Bean Cutworm, and the North Central Integrated Pest Management Center's Regional Pest Alert for Western Bean Cutworm.

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, R stage pest issues (corn rootworm, European corn borer, armyworm, western bean cutworm, foliar diseases, nutritional deficiencies)
  • Check no-till fields/fields with high residue or weeds for slug/snail damage
  • Monitor for weeds, note presence of "who", "how many" and "where"
  • Monitor tasseling corn fields for presence of corn rootworm beetles.

Small Grains:

  • Monitor spring grains for crop stage (heading, grain fill), insect problems and foliar / head diseases
  • Evaluate crop for plant vigor, lodging, maturity / time till harvest
  • Grain bins ready to accept upcoming harvest?

Alfalfa & Hay:

  • Monitor alfalfa seedings for weeds, potato leafhopper & diseases.
  • Check regrowth of established alfalfa stands for potato leafhopper, weed and disease problems.
  • Storage areas cleaned and ready to accept incoming harvest


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

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 through out 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 our Livestock IPM homepage.
  • Consider installing biting fly traps to reduce horse, deer and stable fly populations.


  • Keep areas around storage bins and silos clean and mowed
  • Check areas around storage bins and silos for vertebrate tunneling
  • Check temperature of recently binned grains and baled hay in hay mow


  • Note any repairs needed for recently used equipment: tractors, tillage implements, sprayers, etc. as they are cleaned and serviced.
  • Service hay and grain 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.

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