May 31, 2018

NYS IPM Weekly Field Crops Report-May 31, 2018

View from the Field

Potato Leafhopper (Empoasca fabae)

Aaron Gabriel (CCE Capital Region) and Ken Wise (NYS IPM) report finding potato leafhopper (Empoasca fabae) in Eastern, NY. In a new seeding near Kinderhook, NY we found 20 potato leafhoppers in 10 samples of the sweep net (1 sample=10 sweeps) in 10 inch alfalfa. This is below threshold but a fair amount this early in the season. Here is how to identify potato leafhopper.  Adult potato leafhoppers are lime green and slender about 1/8 inch long. Nymphs are even smaller lime green without wings.

potato leafhopper nymph

Potato Leafhopper Adult

Here is a video we developed on scouting potato leafhopper in alfalfa:

For a potato leafhopper in alfalfa scouting form please refer to the following website:

True Armyworm (Pseudaletia unipuncta)

Jeff Miller (CCE Oneida-Madison County) and Ken Wise (NYS IPM-Eastern NY) report catching true armyworm moths in their pheromone traps. There are no reports of armyworm larvae feeding on corn or small grains.  Last week Aaron Gabriel (CCE Capital District) found small larvae in a hay field in Washington County.  Keep an eye out for this insect pest. Here is a link to an IPM article on true armyworm: .

 Weather Outlook – May 31, 2018

Jessica Spaccio

NOAA Northeast Regional Climate Center

Cornell University

Last week temperatures ranged from 4 to 12 degrees above-normal. Precipitation has ranged from a trace to 2 inches. Base 50 growing degree-days ranged from 40-160.

Showers and thunderstorms Thursday and Friday, some could produce gusty winds and locally heavy rain with perhaps isolated flash flooding.

Today temperatures will be in the 70s to 80s and humid with showers and thunderstorms possible (scattered to numerous, more likely for western to central NY). Overnight lows will be in the 60s.

Friday will be humid with highs in the 80s and showers and thunderstorms likely. Overnight temperatures will be in the upper 50s to mid 60s.

Saturday will be cooler and less humid with seasonable temperatures in the 70s. Scattered showers are possible for southeast NY, but the rest of the state will be dry. Overnight temperatures will be in the 50s.

Sunday highs will be in the upper 60s to mid 70s with dry conditions. Overnight temperatures will be in the 50s.

Monday highs will be in the upper 60s to mid 70s with scattered showers possible. Overnight temperatures will be in the 50s.

Tuesday highs will be in the upper 60s to mid 70s with scattered showers possible. Overnight temperatures will be in the 50s.

Wednesday highs will be in the upper 60s to mid 70s with scattered showers possible. Overnight temperatures will be in the upper 40s to mid 50s.

The seven-day precipitation amounts will range from 1 ¼ inch to 2 ½ inches.

The 8-14 day outlook (June 7-13) favors below-normal temperatures. The precipitation outlook favors near-normal amounts for southeast New York, and favors above-normal amounts for the rest of the state.

Maps of 8-14 day outlooks:

National Weather Service watch/warnings map:

US Drought Monitor

CLIMOD2 (NRCC data interface):


New York Field Crop Pest Degree Day Accumulations for selected locations

(May 31, 2018)


Station Location

Alfalfa Weevil

(Base 48)

March 1

GDDs (Base 50 F)

March 1

Seed Corn Maggot (base 39)

January 1

Black Cutworm (Base 50)

April 24

Ceres 481 410 926 397
Chazy 388 320 755 320
Geneva 505 435 597 434
Highland 572 496 1120 485
Ithaca 489 418 959 417
Massena 386 319 762 319
Northport (Richters) 541 454 1159 433
Valatie 485 416 940 410
Versailles 508 442 988 435
Watertown 372 311 766 311

 Alfalfa Weevil Accumulated Degree Days for Peak Occurrence

(50%) of Alfalfa Weevil at a given Life Stages

Stage              Degree Days

Egg hatch                    280 DD

Instar 1                        315 DD

Instar 2                        395 DD

Instar 3                        470 DD

Instar 4                        550 DD

Cocooning                   600 DD

Pupa                            725 DD

Adult emergence         815 DD


Black Cutworm Degree Days

Degree Days Stage Feeding Activity
0 Moth Capture Egg Laying
90 Eggs Hatch
91-311 1st to 3rd Instar Leaf Feeding
312-364 4th Instar Cutting Begins
365-430 5th Instar Cutting Begins
431-640 6th Instar Cutting Slows
641-989 Pupa No feeding

Source: University of Minnesota Black Cutworm Trapping Network

Seed Corn Maggot Peak Flight and Fly Maggot Free Degree Days

Base Temp = 390 F Peak 1st Generation Seed corn maggot fly free degree days Peak 2nd Generation Seed Corn maggot fly free degree days Peak 3rd Generation Seed Corn Maggot fly Free degree days
degree days 360 810 1,080 1530 1800 2250

Source: Insect IPM for Organic Field Crops: Seed Corn Maggot by Katelin Holm and Eileen Cullen

Clipboard Checklist

Keith Waldron, NYS IPM


*Pre- and post-plant weed evaluation, timing cultivation and/or post-emergent weed management
*Watch for early season weeds: winter annuals, chickweed, henbit, field penny cress, shepherd’s purse, giant and common ragweed, purple deadnettle, lambsquarters, redroot pigweed, velvet leaf, Pennsylvania smartweed, common sunflower, quackgrass, foxtail

*Evaluate established legume stands for harvest.
*Monitor for alfalfa weevil, crown or foliar diseases
*Monitor new seedings for Pythium blight and Phytopthora Root Rot.
*Monitor for Alfalfa Snout Beetle (In Oswego, Jefferson, Cayuga, Wayne, Lewis, St. Lawrence, Clinton, Essex, and Franklin counties)

Small Grains:
*Monitor winter grain fields for growth stage, disease presence or risk, weed issues (such as winter annuals, corn chamomile and chickweed), growth stage, number of tillers

* Evaluate stands for risk of fungal diseases (See above Dr. Bergstrom’s article above)
*Check stands for soilborne virus diseases, Wheat spindle streak mosaic and Soilborne wheat mosaic, check for signs of powdery mildew or other maladies, cereal leaf beetle, weed escapes, goose damage

*Plant corn as conditions allow
*Pre- and post-plant weed evaluation, timing cultivation and/or pre- and post-plant weed management

*Emergence: assess stand, population count, bird and early season insect issues e.g. black cutworm, wireworm, white grubs.

*Plant soybeans as conditions allow
*Pre- and post-plant weed evaluation, timing cultivation and/or post emergence weed management

*Emergence: assess stand, population count

Check and mend fences as needed.
*Check crop growth
*Monitor fields for invasive species, plants harmful to livestock
*Review/Plan rotation system

*Remove / clean soil and crop debris from equipment
Arrange for custom weed control or check your own application or cultivator equipment for repairs.
*Carry appropriate / necessary NYS DEC and EPA required documents: (pesticide applicators license, pesticide labels, MSDS sheets, etc.) with application equipment

-planting equipment – maintain records on planting rate per field

-manure spreaders – maintain records on amount spread per field

-pesticide application equipment – Check nozzles, pumps, etc., recalibrate pesticide application equipment before use.

* Check stored grain bins for temperature, moisture and signs of mold and insects. Aerate, core, transfer grain or treat as necessary
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