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Weekly Field Crops Pest Report 2012

May 21, 2012, Volume 11 Number 6

  1. View from the Field
  2. Weather Outlook
  3. Biological Control of Alfalfa Weevil
  4. Fusarium Head Blight Update for New York
  5. Growing Degree Days
  6. Clipboard Checklist
  7. Mark Your Calendars
  8. Contact Information

View from the Field

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Julie Hansen reports potato leafhopper this last weekend near Ithaca. Keep an eye on this pest on alfalfa. They travel on weather fronts from points south and southwest in search of host plants. (They feed on about 150 different plants.) With the recent storms, potato leafhopper maybe in an alfalfa field near you.

Look for a lime-green adult about 1/8 inches long. (Photo below.) The nymphs look much like the adult but are smaller and are bright yellow-green. More on potato leafhopper in future issues of the pest report.

potato leafhopper

Last week I reported that there were a few Cereal Leaf Beetle larvae in the oat field next to the Cornell Research Farm in Valatie. This week there were many more. They were not close to an economic threshold with less than one per every four plant but you could readily find larvae in the field.

Alfalfa Weevil larvae were plentiful this week at the Valatie farm with 100% tip feeding across the whole farm. Some of the alfalfa was even turning brown because of so much larval feeding pressure. The larvae ranged from 2nd to 4rd instar.

I collected 20 pupa and all were parasitized with Bathyplectes spp. For more information on biological control by Bathyplectes see article below.

Aaron Gabriel (Capital Region) reports seeing seed corn maggot damage in corn. The interesting thing is he found them in seed treated with Poncho 250 and 1250. These insecticides are meant to control this pest. (He did state that the seed corn maggots inside the 1250 did not look too lively. The 1250 is the higher rate of clothianidin for corn rootworm larvae.)

Aaron also reports black cutworm damage in corn. The cutworm larvae were about a inch and not yet fully grown. They will grow to 1.25 inches. This is the first report of cutworm damage in NY. Keep an eye out for this pest.

Keith Severson reports turkey damage in corn. The corn was planted rather shallow at only 1 inch deep. Most birds eat the seed and not just the above-ground foliage. By planting so shallow it makes it easy for birds to dig (pluck) out the seed, If the seed is planted at 2 inches they may get a few seeds but it is too much work and they move on to easier pickings! Kevin Ganoe did a demonstration on corn seed planting depth at the SUNY Cobleskill Farm in 2008. All the corn that was planted at an inch or less was picked out of the soil by birds. From 1.5 inches or deeper no seeds were picked.

turkey damage

Photo: Birds removed all shallow-planted corn seeds.

Fireflies were observed in the Finger Lakes (Geneva) area this week. Firefly activity has, in the past, been associated with the timing for corn rootworm egg hatch. This weeks sightings roughly coincide with the timing of first firefly sightings reported in 2009 (6.3.09), 2010 (5.21.10) and 2011 (6.6.11).

Weather Outlook

May 24, 2012
Jessica Rennells, Northeast Region Climate Center, Cornell University

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Last week temperatures ranged from three to nine degrees above normal for most of the state. Precipitation amounts ranged from just a trace up to two inches. The base 50 growing degree-days ranged from 50 to 100. Today will be mostly sunny with a slight chance for showers and thunderstorms, more likely in the Catskill area. Highs will be in the upper 70s and low 80s. Lows will be in the upper 50s and low 60s. Friday well have a continued chance for showers and thunderstorms as a week front passes through, with highs in the upper 70s to mid 80s. Overnight temperatures will be in the mid 50s to low 60s. Saturday will be mostly sunny with highs will be in the low to mid 80s with lows in the upper 50s and low 60s. Sunday will be hot and sunny with temperatures in the mid 80s to near 90; there is a chance of showers and thunderstorms. Lows will be in the 60s. Monday will be sunny with highs in the mid 80s to near 90, again with a chance of showers and thunderstorms. Overnight temperatures will be throughout the 60s. Tuesdays temperatures will be in the low 80s with showers. Lows will be in the 60s. Wednesday will be cooler with highs in the 70s and scattered showers. Lows will also be cooler with temperatures in the 50s.

The five-day precipitation amounts will range from half an inch up to 1.75 inches. The 8-14 day outlook is showing normal temperatures and above 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)

Biological Control of Alfalfa Weevil

Ken Wise

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Several decades ago, alfalfa weevil used to be the most damaging insect pest of alfalfa in the US. We have three different strains: the western strain introduced into Utah (1904), the Egyptian strain introduced into Arizona (1939) and the eastern strain introduced into Maryland (1951). In NY, we have the eastern strain of the alfalfa weevil (AW).

A pest introduced to a new location that has no natural controls is considered an exotic or invasive species. USDA saw that to help to manage alfalfa weevil in the long term, they would need to find and release natural enemies from their native habitat in the Near East and Central Asia. In 1957, the USDA released several species of parasitoids in the US to control AW. Of the original releases Bathyplectes curculionis was the only one to effectively establish and parasitize AW. The USDA made a second release in 1980 and several more species established. Two are common in NY: Bathyplectes curculionis and Bathyplectes anurus. Both are tiny parasitic wasps that lay eggs in the prepupa of AW. These releases took a very serious pest and reduced its damage. While you can still have damage from AW weevil, it is far less that before the parasitoid releases. You can see the biological control in action by looking at several of the pupa. At about 600 AW degree days, look for the cocoons and alfalfa leaflets as in the photo below:

alfalfa weevil coccoon

Alfalfa weevil cocoon

Open the cocoon, and if the weevil is healthy you will find a nice green colored soft-bodied alfalfa weevil. If parasitized, you will only find a small (1/8 inch long) mahogany colored pupa cocoon of the wasp that parasitized the weevil. Some Bathyplectes cocoons have a white line around the circumference of the cocoon. You can even distinguish between Bathyplectes curculionis and Bathyplectes anurus species by looking at the pupa case. Bathepletes anurus has a raised white band around the pupa case while B. curculionis is not raised. Plus B. anurus when disturbed will cause the pupa case to jump a little and B. curculions will not.

Batheplectes coccoon

(Batheplectes anurus cocoon: white raised stripe on pupa next to an alfalfa weevil larvae).

I did a small study 9 years ago on the percent the pupa that were parasitized by Batheplectes species. 65% of the 200 I collected were parasitized. Biological control is at work on AW in NY.

Fusarium Head Blight Update for New York

Dr. Gary Bergstrom, Plant Pathologist, Cornell Univesity

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The majority of New York's winter wheat crop is now or soon will be flowering.  This is the decision time for application of an efficacious triazole fungicide (i.e., Caramba, Prosaro, or Proline) for suppression of FHB and control of fungal diseases on flag leaves.  A flowering application of triazole fungicide should be based on Fusarium head blight (FHB) risk as well as the risks of powdery mildew, rust, and fungal leaf blotches in the upper canopy based on scouting of individual fields.  The FHB Risk Assessment Tool indicates low risk for FHB infection throughout the state.  Forecasts for the next several days predict warm temperatures and a continuing chance of scattered thunderstorms, but not long durations of leaf wetness.  Check the Risk Assessment Tool and your local weather forecast frequently during this critical window of wheat development.  And be aware of the 30 days to harvest restriction for the application of triazole fungicides.

For more details, go to the FHB Risk Assessment Tool.

Past blog entries for this region.

Growing Degree Days

Ken Wise, NYS IPM

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CURRENT Accumulated Growing degree days (48F Base):

March 1 - May 2, 2011

Base 48 F
Base 50 F
*Indicates missing data
source: NEWA's Degree Day data page

Alfalfa Weevil Prediction Model
A website at NEWA can predict alfalfa weevil development in your area. Just select a weather station near you and it will give you the AW degree days.

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.
*Walk fields to check crop condition, growth, and emergence. Look for signs of vertebrate pests (birds, ground hogs, deer, etc.).
*Mow around farm buildings to minimize rodent and other pest habitat

Alfalfa and Grass Hay:
*Monitor alfalfa for crop condition, watch re-growth for alfalfa weevil, potato leafhopper, and diseases.
*Evaluate alfalfa seedings for weeds, insects (potato leafhopper) & diseases.

Small Grains:
*Monitor winter grain fields for crop growth stage, signs and symptoms of diseases, weed pressure, insects (cereal leaf beetle)
*Monitor winter wheat for foliar & grain head diseases, potential for Fusarium Head Blight

Field Corn:
*Post emergence: Determine corn plant populations, monitor for emergence problems, weeds, noting presence of "who", "how many" and "where"
* Early season corn pests: seedling blights, seed corn maggot, white grub, wireworm, black cutworm, slugs, birds
*Adjust post emergence weed control actions

*Post emergence: Determine plant populations, monitor for germination and emergence problems, monitor for weeds, noting presence of "who", "how many" and "where"
* Monitor for soybean aphid

*Check and mend fences as needed.
*Check crop growth
*Check for presence of undesirable plant species harmful to livestock.
*Review/Plan rotation system

*Arrange for custom weed / disease management or check your own application or cultivator equipment for readiness or need for repairs.
*Check nozzles, pumps, etc., recalibrate pesticide application equipment regularly before use.
*Calibrate manure spreaders - maintain records on amount spread per field

*Check forage allocation and anticipate feed program adjustments as forages from previous year are used up
*Plan where forages should be stored for optimum allocation next feeding season

Cattle on Pasture:
*Monitor animals for presence of face flies, horn flies and stable flies. Action guidelines: face flies (average 10 per animal face), horn flies (average 50 / dairy, 200 / beef cattle per animal side), stable flies average 10 per animal  (all four legs)
*Check feed bunk / water source locations for signs of stable fly breeding (moist undisturbed organic matter spilled feed, round bales, etc.), minimize source of moist organic matter i.e. fly breeding areas in barn and in adjacent animal loafing yard
*Check paddocks for forage quality / quantity, rotate as appropriate
*Check paddocks for vegetation poisonous to livestock
*Consider use of fly traps to help reduce deer, horse and stable fly populations

Dairy Cattle Barn Fly Management:
*Monitor animals and barn area for house fly, stable fly and other pest management needs including presence of rodents and birds.
*Check facilities for favorable fly breeding conditions: (organic matter + moisture): leaks in watering systems, roof gutters for leaks and potential overspill, drainage,
*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 * Continue fly monitoring: install "3X5" index card fly speck monitoring cards throughout barn
*Use, replenish, replace fly management materials: sticky fly tapes/ribbons, insecticide baits, natural enemies (parasitoids), fly population monitoring (3 x 5) spot cards

*Consider purchase and release of Muscidifurax raptor and/or M. raptorellus natural enemies of house and stable fly pupae

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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CORNELL UNIVERSITYS SMALL GRAINS MANAGEMENT FIELD DAY, Musgrave Research Farm, 1256 Poplar Ridge Road, Aurora, NY, Thursday June 7, 2012. The program will run from 10:00am-12:00 noon. Registration begins at 9:30 am.
An educational program of the Integrated Field Crop, Soil, and Pest Management Program Work Team in conjunction with Cornell Cooperative Extension will host the Small Grains Management Field Day with research demonstrations and presentations of interest to the local farming community. DEC and CCA credits will be available.  For more information, please contact Mary McKellar at or 607-255-2177

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