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Weekly Field Crops Pest Report 2010

May 28, 2010             Volume 9 Number 6

1. View from the Field

2. Weather Outlook

3. Cereal Leaf Beetle

4. How to Recognize Scab (Fusarium head blight) on Wheat

5. Lady Beetle of the Week

6. Growing Degree Days and Alfalfa Weevil Development in NYS

7. Clipboard Checklist

8. Mark Your Calendars

9. Contact Information

View from the Field

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I found potato leafhoppers in 2 fields of alfalfa at the Cornell Farm in Valatie. I found just a few but it is important to know they are in NY. Tip feeding by alfalfa weevil ranged 5 to 20 percent. I am seeing 2nd to 3rd instar alfalfa weevil larvae in the fields.

Mike Stanyard reports cereal leaf beetles in oats.   See article below on cereal leaf beetle. He also reports a severe leaf rust infestation in a wheat field in Western NY. The field has since been sprayed with a fungicide.

Keith Waldron reports a heavy infestation of alfalfa weevil in alfalfa at the experiment station in Geneva. Alfalfa weevils are beginning to pupate. He reports many larvae appear infected with diseases and Bathyplectes spp (tiny beneficial wasps called parasitoids) that lay their eggs on the inside of the alfalfa weevil pupa and then feed on the weevil.

Alfalfa weevils in many areas around the state are in their late instars approaching cocoon stage. Recall that the third instar, about 3/8 inch long, consumes approximately 80% of the foliage eaten by all stages. Alfalfa weevil have 1 generation per year and leave the field shortly after adult emergence following their cocoon stage.

Keep on the lookout:
Watch for signs of alfalfa weevil feeding in windrows following alfalfa harvest. The action threshold for treating the field post-harvest is 50% or more regrowth tip feeding.

States adjacent to NY continue to report black cutworm and armyworm activity.  We have not, to date, heard of any significant issues with these insects in NY so far this season.

Warm weather can be favorable for nuisance and biting flies affecting animals in and around facilities and on pasture. Monitor animals and facilities for fly activity.

Weather Outlook

Jessica Rennells
NOAA Northeast Climate Center, Cornell University

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Last week was hot and mostly dry.  Temperatures were 6 to 12 degrees above normal.  Most of the state had .01 to half an inch of precipitation.  Areas around the eastern Central Lakes and western Mohawk Valley had less than .01 inches.

The base 50 Growing Degree Days ranged from 75 to more than125.  Most of the state had 100-125 growing degree days.  The state ranges from 3 days behind to more than 14 days ahead of last year.   Compared to normal most of the state is 7 to 14 days ahead.

This week we will continue to see warm temperatures.  Today’s temperatures will be in the mid 70’s to mid 80’s.  The overnight temperatures will be in the 40’s and 50’s.  Some showers are expected this afternoon and evening.  Friday will have highs in the 70’s and lows in the 40’s and low 50’s.  Saturday’s temperatures will be in the 70’s during the day and the 50’s at night.  Sunday will have highs in the upper 70’s and low 80’s and lows in the 50’s.  Monday will be cloudy with temperatures in the low to mid 80’s during the day and upper 50’s at night.  Tuesday will have highs in the 70’s and lows in the upper 50’s and low 60’s.  There will be a light chance for scattered showers across the state for Tuesday and Wednesday.  Wednesday the highs will be in the low to mid 70’s and the lows in the upper 40’s to mid 50’s. 

The five day precipitation totals will be 0.10 to half and inch.  The 8-14 day outlook is showing below normal temperatures and above normal precipitation.   The drought monitor is showing abnormally dry conditions for Oswego, Jefferson, St. Lawrence, Franklin, Lewis, and Oneida counties.

Cereal Leaf Beetle

Ken Wise

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Cereal leaf beetle can be an occasional problem in small grains. Some years they do reach action thresholds and need to be controlled. Eggs can be found on the upper surface of the leaves near the midrib. Eggs are elongate, yellow to brown about 1/16 inch long, and are laid in chains of two or three. Small black slug-like larvae emerge from the egg and reach about a 1/4 inch long. Larvae feed on the leaf surface, leaving long narrow white strips between the veins. The adults are 3/16 inch long with metallic bluish-black head and wing covers. Cereal leaf beetle is more of a problem in oats but can occasionally reach threshold levels in wheat.

The threshold for cereal leaf beetle is three or more eggs and larvae per stem before the boot stage of oats or one or more larvae per flag leaf after the boot stage. Check 30 stems distributed throughout a field to determine if the field are at an action threshold.

Figure 1: Cereal leaf beetle eggs and larva 

How to Recognize Scab (Fusarium head blight) on Wheat

Ken Wise

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One of the most devastating diseases of wheat is Scab or also called “Fusarium head blight.” This disease infects the grain head at flowering. The disease builds up in corn, wheat and other grain residues. During the day the spores are carried up into the atmosphere and at night settle out across the landscape. If it rains at flowering and spores are present there is a good chance the grain will become infected with the disease. The first symptoms of Fusarium head blight occur shortly after flowering. Diseased wheat heads exhibit premature bleaching as the pathogen progresses.  One or more spikelets located in the top, middle, or bottom of the head may be bleached. Over time, the premature bleaching of the spikelets may progress throughout the entire head. If the environment is warm and moist, aggregations of light pink/salmon colored spores may appear on the rachis and glumes of individual spikelets. Later in the season, bluish- black spherical bodies may appear on the surface of affected spikelets. As symptoms progress, the fungus colonizes the developing grain causing it to shrink and wrinkle inside the head. Often, the infected kernels have a rough, wilted appearance, ranging in color from pink, soft-gray, to light-brown.

Figure 3: Symptoms of Fusarium head blight

For more information regarding Fusarium head blight management see Cornell Guidelines for Pest Management of Field Crops: Chapter 5.7 Managing Diseases of Small Grain Cereals.

Integrated Management of Fusarium Head Blight in Wheat: Introduction of Scab Smart.

For information regarding Fusarium head blight and management of other small grain diseases…..
Come meet the experts at the Small Grains Management Field Day at the Cornell Musgrave Farm in Aurora NY, next Thursday, June 3.

Lady Beetle of the Week

Ken Wise

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The parenthesis lady beetle (Hippodamia parenthesis) is native to North America. Larvae may consume about 25 aphids per day. Adults can eat as many as 50 per day depending on Hippodamia spp. This small beetle is only 4 to 5 millimeters.

Figure 3: Adult parenthesis lady beetle 

Growing Degree Days and Alfalfa Weevil Development in NYS

Ken Wise

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Growing degree Days for peak (50%) Occurrence of Alfalfa Weevil growth stage:

Stage or Event
Accumulated growing degree days (48F base temperature)
Eggs hatch
Instar 1
Instar 2
Instar 3
Instar 4
Adult Emergence
(Note: for alfalfa weevil predictions use Base Temp of 48F)

CURRENT Accumulated Growing degree days (48F Base)

March 1 -   May 26, 2010

Base 48 F
Base 50 F
*Indicates missing data
source: NEWA

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, gound hogs, deer, etc.).
*Watch for early season weeds: winter annuals: chickweed, henbit, purple deadnettle, field penny cress, shepherd's purse; annuals: giant ragweed, lambsquarters, Pennsylvania smartweed, dandelion, bedstraw.
*Mow around farm buildings to minimize rodent and other pest habitat

Alfalfa and Grass Hay:
*Monitor alfalfa for alfalfa snout beetle (In Oswego, Jefferson, Cayuga, Wayne, Lewis, St. Lawrence, Clinton, Essex, and Franklin counties)
*Monitor alfalfa for crop condition, alfalfa weevil, potato leafhopper, foliar, systemic and crown rot diseases.
*Evaluate alfalfa seedings for weeds, insects (potato leafhopper) & diseases.
*Monitor alfalfa and grass stands to determine optimal harvest date.
Watch windrow areas of harvested alfalfa for signs of alfalfa weevil feeding

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

Field Corn:
*Finish corn planting
*Using a Bt hybrid? Have a refuge plan?
*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

*Pre-plant field assessment and weed evaluation
*Post emergence: Determine plant populations, monitor for germination and emergence problems, monitor for weeds, noting presence of "who", "how many" and "where"

*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 control 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 planting equipment - maintain records on crop planting rate per field
*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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June 3 -- Small Grains Management Field Day, Musgrave Research Farm, 1256 Poplar Ridge Rd., Aurora, NY  Free registration at 9:00am.  Program runs from 10:00am-12:00 noon.  Dec and CCA credits have been applied for For more information contact Larissa Smith at 607-255-2177  or

July 14-- Weed Science Field Day, Thompson Research Farm, Freeville, NY (morning program)

July 14-- NYSABA Summer BBQ, Musgrave Research Farm, 1256 Poplar Ridge Rd.,  Aurora, NY (12:00 noon)

July 14-- Weed Science Field Day, Musgrave Research Farm, 1256 Poplar Ridge Rd., Aurora, NY (1:30pm 5:00pm)

July 22-- Aurora Farm Field Day, Musgrave Research Farm, 1256 Poplar Ridge Rd., Aurora, NY (10:00am-3:00pm)

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