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Weekly Field Crops Pest Report 2012

August 3, 2012, Volume 11 Number 16

  1. View from the Field
  2. Weather Outlook
  3. Western Bean Cutworm Update
  4. Clipboard Checklist
  5. Contact Information

View from the Field

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Potato leafhopper (PLH) is still the pest of the week in many areas of the state. Reports for some locations, however, indicate PLH populations may be lower this week than last. A welcome reprieve, letís hope this trend continues.

Second generation armyworm still active in some areas of western and northern NY. Grass hay fields and mixed grass : legume stands still the primary targets. There have been reports of ĺ to 1 inch long armyworm larvae. Some affected fields have diseased larvae indicating a potential ramping up of natural enemies.

Spider mites continue to be active in soybeans, corn and other crops.
Rains have helped improve growing conditions.

Alex Wright with Carolina Eastern-Vail, Inc reports finding moderate to moderately high levels of Northern Corn Leaf Blight. See photo below for symptoms of the blight.

northern corn leaf blight
Northern Corn Leaf Blight (Photo taken by Alex Wright)

Weather Outlook

August 2, 2012
Jessica Rennells, Northeast Region Climate Center, Cornell University

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Last week temperatures ranged from 0 to 3 degrees above normal for most of the state.† Rainfall amounts ranged widely from a trace to over 2 inches.† A majority of the state had 1-2 inches, part of Niagara county and the Northern portion of the state had less than an inch, highest amounts were in western NY and the lower Hudson Valley.† The Base 50 growing degree-days ranged from 100 in the northern areas to 175.

Warm temps continue.† Chance for showers & thunderstorms Fri Ė Mon.† Possible severe weather on Sunday Ė watch your local National Weather Service office for watches and warnings.

Today (Thursday) temperatures will rise into the mid 80ís to near 90ís with dry conditions as high-pressure builds in.† Lows will range from the upper 50ís to upper 60ís. Friday temperatures will be in the mid 80ís to low 90ís with showers and thunderstorms possible from a passing warm front.† Overnight temperatures will be in the mid to upper 60ís. Saturday highs will continue to be warm in the mid 80ís to low 90ís, again with scattered showers and thunderstorms.† Overnight lows will be quite warm in the mid 60ís to low 70ís.† Sundayís temperatures will be closer to normal, ranging throughout the 80ís, with an increases chance for showers and thunderstorms.† Some storms could produce severe weather.† Lows will be throughout the 60ís. Monday will be in the low to mid 80ís, with some scattered showers and thunderstorms possible.† Lows will be in the upper 50ís to low 60ís. Tuesday will be mostly sunny with highs in the low to mid 80ís.† Lows will be in the upper 50ís and low 60ís. Wednesday temperatures will be in the low to mid 80ís.† Lows will be in the low to mid 60ís.

The five-day precipitation amounts will range from Ĺ of an inch to 1 ľ inches. The 8-14 day out look is showing normal temperatures and normal precipitation.†† Abnormally dry and moderate drought conditions remain very similar to last week.† Portions of the Champlain Valley and northern Hudson Valley are no longer abnormally dry.

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 dropped off this week indicating peak flights occurred last week, two weeks ahead of peak catches observed in 2010 and 2011. A total of 849 WBC moths were caught in the 61 traps reporting this week, down from 1006 WBC moths caught in 62 traps last week. Trap catches ranged from 0 to 145. The majority of our NY trap catch numbers are still relatively low and do not indicate any cause for concern. Interestingly, 14 traps have caught less than a total 10 WBC moths so far this season. High counts this week came from: Franklin (70), Jefferson (145) and Wyoming (93). The large number and the condition of the moths in these traps suggests many of these moths travelled some distance and were migrants, most likely from Ontario. (Moths recently captured in NY have typically been in relatively good condition, indicating local sources).

Average number of western bean cutworm moths captured per trap.

Corn fields adjacent to trap locations in Wyoming county were checked this week for egg masses, none were found. Suspected WBC egg masses were again collected in Franklin county this week. The NY WBC trapping program will continue through August.

The timing of peak flight provides a guideline for monitoring field and sweet corn for egg masses: search tassel-emergence and silk stage fields for western bean cutworm eggs and larvae. The threshold for WBC used in Michigan and Ontario is 5% of plants with egg masses. As with other boring insects such as ECB, it's important to control western bean cutworm larvae before they enter the ear and are protected from an insecticide application. Focus scouting on fields that have plants with at least a tassel developing in the whorl of the plant as well as those with the tassel fully emerged but not fully shedding yet. These fields seem most attractive for the moths. If fields have variable plant heights, you’ll likely find a higher concentration of eggs on shorter corn.

Transgenic field corn hybrids with the Cry1F (e.g. Herculex, SmartStax) and Vip3A (Agrisure Viptera Bt) Bt protein are labeled effective against western bean cutworm. Read hybrid labels closely for what resistance is “built in” Ė (See also “Handy Bt Trait Table” link provided below). In non-Bt corn or transgenic corn that does not provide any protection against WBC treatment is justified when 5% of plants are infested. For sweet corn, consider treatment if eggs or larvae are found on >4% of plants for the processing market or on >1% of plants for fresh-market, and should be applied at 90-95% tassel emergence. Time spray application for just after egg hatch when small larvae are present at the top of the plant.  Egg hatch occurs a day or two after the egg masses turn purple (typically 5-7 days after being freshly laid). 

In Dry Beans: WBC thresholds for dry beans have not yet been established.  However, in the western US, researchers found a relationship between trap numbers and the risk of pod and bean damage. Thus, pheromone traps are used to determine the number of moths present and time of peak moth flight. Pod feeding typically takes place 10 to 21 days after peak moth flight so having a trap at the field location helps determine when moth peak occurs.† The trap counts provide information to help determine when to begin scouting for WBC damage and to determine a need for treatment.

Scouting for egg masses and larvae in dry beans is extremely difficult. Egg masses are laid deep in the canopy on the underside of the leaves, and larger larvae hide in the soil during the day. One recommendation suggests insecticide treatments are recommended when one or more larvae are found per row foot (Michel et al). Another, easier method comes from Michigan State University (Difonzo) and Ontario (Baute) researchers who suggest if a corn field directly adjacent to the dry bean field has reached threshold of 4 - 8% of plants with WBC egg masses the dry bean field should be considered at risk and the dry bean field should be scouted for leaf and pod feeding and sprayed if damage is seen.

More WBC monitoring information is available at:
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:

Handy Bt Trait Table

Stay tuned for more information.

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, 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.
* Storage areas cleaned and ready to accept incoming harvest
* 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 accidentsÖ
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