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Weekly Field Crops Pest Report 2012

June 22, 2012, Volume 11 Number 10

  1. View from the Field
  2. Weather Outlook
  3. Time to Start Scouting for Potato Leafhopper on Alfalfa
  4. Dairy Cattle Pest Management Resources
  5. Mark Your Calendars
  6. Contact Information

View from the Field

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The True Armyworm is center stage again for the 4th week. They are being found statewide and mostly in grasses and mixed stands. There have been reports of armyworm over threshold in oats and corn. The majority of the damage is still occurring in Western NY and into St. Lawrence county. But there are reports of some fields over threshold in Eastern, NY from Clinton County to Dutchess County and out to Oneida County. A light of hope is that in Eastern NY extension educators are reporting that some of the populations are showing signs of biological control. Both parasitoids and pathogens have been found in populations of armyworms. The pathogen can wipeout a population armyworms in a field. Parasitoids can hold a population in check so it does not build. Again as we have said you never know where and when this will happen. It might come to a field near you!

armyworm damage

Armyworm damage with true armyworm (Photo by Dale Dewing)

A question was raised this week on whether the 2nd generation of true armyworms would cause more damage to crops Elson Sheilds (Cornell Field Crops Extension Entomologist) responded that there is no useful reason to monitor or worry about the second generation of armyworm!!  The same behavior which makes this insect a long-distance migrant (the need to fly long distance before settling down to lay eggs) is in force in all generations.  In addition, the dilution in the vast habitat in NY reduces any potential to a non problem.  The reason we had a spring problem was that millions of moths were concentrated into a small zone due to weather issues and dumped on us in a wide swath from Michigan across Ontario to NY.

Paul Cerosaletti and Dale Dewing are reporting black cutworm damage in corn. Paul stated that they have found damage in very clean fields (weed free) of corn. They also found a loose smut on the heads of barley. I also found a lot of loose smut in organic wheat in Essex county last week.

loose smut

Loose Smut on Barley (Photo taken by Paul Cerosaletti)

Gary Bergstrom reports finding several wheat diseases near Aurora this week. These include brown leaf rust, striped leaf rust, eye spot foot rot, and Fusarium foot rot. Rusts can dramatically reduce yields on wheat. Eye spot root rot and fusarium root rot can also affect yield.

strip rust

Strip Rust on Wheat (Photo taken by Gary Bergstrom)

Potato leafhoppers (PLH) can be found readily on alfalfa throughout the state. In western NY Mike Stanyard is reporting very high levels of PLH on alfalfa. He stated that they are even over threshold on PLH resistant alfalfa. The rest of the state is reporting finding PLH but not at threshold levels. See article below on how to scout for PLH in alfalfa.

An interesting thing is that Mike Stanyard reports that PLH are at high levels in soybeans. Elson Shields (Cornell Field Crops Extension Entomologist) responds that pubescent soybeans are not generally damaged by PLH.  The plant hairs interfere with the adult’s egg laying ability.  Eggs are inserted in the leaf and stem tissue and the plant hairs interfere with those activities.  It is a mechanical resistance.  Remove the plant hairs (glabrous) and soybeans are very susceptible to PLH.  In pubescent soybeans, you will find adults but rarely nymphs.  It is the nymphs which cause the majority of the economic damage.

Keith Severson reports an issue we should all be aware of “BEES”! This time of year with fields being sprayed with insecticides it is important to consider protection of bees. Always follow insecticide label instructions. If there are flowering plants in the fields you are spraying you have the potential to kill bees. Many times the bees will carry an insecticide back to the hive and kill many more. If you observe bees in a field you are going to spray you could consider a better time of the day to spray. Spraying in the evening after bees have returned to their hives is one option. Notify the bee keeper of your intentions to treat a field.

Western Bean Cutworm (WBCW) trapping began statewide the week of June 10. Twenty-eight locations are now reporting WBC collection data.

The first WBC moths (2) were collected last week in Eden (Erie County) in a sweet corn field. This week WBC moths (1 each) were collected in Eden and Lockport (Niagara county). Both traps were adjacent to sweet corn fields.

Weather Outlook

June 21, 2012
Jessica Rennells, Northeast Region Climate Center, Cornell University

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Last week temperatures ranged from normal to 6 degrees above normal. Precipitation amounts ranged from a trace to half an inch. The base 50 growing degree-days ranged from 75 to 150 for most of the state.

Hot! Well have one more day of heat before a cold front comes through to bring us back to normal temperatures. Temperatures will continue to cool into next week as a large upper low persists over the Northeast.

Today will be hot & humid with temperatures in the upper 80s and throughout the 90s, and heat indices into the 100s. A cold front will move across the state, starting in the evening, and bring a chance of showers and thunderstorms. Overnight temperatures will be in the mid 60s to low 70s. Friday temperatures will be closer to normal, in the upper 70s and low 80s. The Catskills and lower Hudson Valley could still see some near 90. Showers and thunderstorms will be possible as the front moves along. Lows will be in the mid 50s to low 60s. Saturday will be sunny with highs in the upper 70s and low 80s. Lows will be in the mid 50s to low 60s. Sunday will be partly sunny with temperatures in the mid 70s to low 80s. Overnight temperatures will be in the mid 50s to low 60s. Monday scattered showers will be possible with highs only in the low to mid 70s. Lows will be in the 50s. Tuesday will be cool with highs in the mid 60s to low 70s and a chance of showers. Lows will be in the 50s.Wednesdays temperatures will also be cool, in the mid 60s to low 70s. Overnight temperatures will be in the 50s. The five-day precipitation amounts will range from .25 to 1.25 inches. The 8-14 day outlook is below normal temperatures and normal precipitation.

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)

Time to Start Scouting for Potato Leafhopper on Alfalfa

Ken Wise, NYS IPM

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Scouting alfalfa fields is the key to early detection of potato leafhopper infestations. Use a 15-inch diameter sweep net to determine the potential risk a potato leafhopper infestation may pose to your alfalfa. Scouting for potato leafhopper starts after the first cutting of alfalfa (about the first part of June) till the first fall frost. You will want to use a potato leafhopper sequential sampling plan to determine if an infestation requires management or not. The first thing to do is determine the height of your alfalfa. Smaller plants are more vulnerable to potato leafhopper; thus there are different action thresholds for different heights of alfalfa. The second thing you will need to know is how to sample for potato leafhopper. A sample consists of a set of 10 sweeps of the net. A sweep is one pass in front of you as you walk through the alfalfa. The return swing is counted as another sweep. Sequential sampling reduces the time spent in each field and tells you whether to treat (management action) or not treat (no management action). Sequential sampling is particularly helpful in minimizing time required to make a management decision in situations where PLH populations are very high or very low. Use the following chart to determine potato leafhopper infestation levels.

plh chart

Write down the number of potato leafhoppers for each sample taken on the card. Add each sample to the next, keeping a running total of potato leafhoppers. You will need to take at least 3 samples using the sequential sampling method. On the sequential sampling card “Don’t Treat” is defined as no treatment (no management) needed at this time and “Treat” is defined as treatment (management) needed within in a week. If the sample is smaller than the “Don’t Treat” number stop and scout 7 days later. If the number of leafhoppers is larger than the “Treat” number then management action needs to be taken within a week. If the number of potato leafhoppers fall between “Don’t Treat” and “Treat” then continue and take the next sample till a decision can be determined.

Dairy Cattle Pest Management Resources

Keith Waldron, NYS IPM

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Summer is here and warmer temperatures have been favorable for potential increases in fly pests affecting dairy animals and other livestock.

A quick source of factsheets, management recommendations and other resources on Livestock (dairy cattle, poultry, sheep, goats, swine, and horses) Integrated Pest Management can be found at: and
For those with a specific interest in dairy barn fly management an archive of a 2 hour Web stream broadcast is available for viewing or download at:

Mark Your Calendars

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Tuesday, 3 July 2012
For Seed Growers, Seed Treatment Applicators, and other Seed Professionals
Place: NYSIP Foundation Seed Barn, 791 Dryden Rd., Rt. 366, Ithaca, NY
Time: 8:30 AM-12:00 noon (registration starts at 8:30 and the program runs fro 9:00 until noon)

Freeville, NY (10 miles Northeast of Ithaca, Fall Creek Road, Rt. 366 extension)
8:00 a.m. Registration
Coffee (beverage), doughnuts, and informational trial packet
8:30 a.m.-11:30 a.m. Vegetable Crop Weed Control (Bellinder)

Aurora, NY (Poplar Ridge Road, connects 90 and 34B)
12:00 1:30 p.m. NYSABA Pork BBQ lunch at Musgrave Research Farm.
1:30 p.m. Registration
2:00 - 5:00 p.m. Field Crop Weed Control (Hahn)
CCA and DEC Credits have been requested for field crop and vegetable

July 18-Robert B. Musgrave Research Farm Field Day
1256 Poplar Ridge Road, Aurora, New York
WEDNESDAY, July 18, 2012, 9:00-3:00 pm

FREE and open to all!
Registration at 9:00 with Coffee and Donuts (no preregistration)
FREE Lunch will be available at 12:00 noon
Pesticide Applicator and Certified Crop Advisor Credits will be available
Questions: Please call (607-255-2177) or email ( Mary McKellar

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