Weekly Field Crops Pest Report 2008
View from the Field
Message from Julie Dennis
Julie Dennis will not be a part of the team of regular contributors
to the NYS IPM Weekly Field Crop
Eastern and Western NYS
True Armyworm is the pest of the week. Several extension educators across the state have see armyworm levels from minor infestations to well over threshold levels in corn and winter wheat. Keep a close eye on small grains, pasture, grass hay, and corn. True armyworm larvae appear smooth, cylindrical, and pale green to brownish when they are still small. Mature larvae are smooth and marked with two orange, white-bordered strips on each side. True armyworm ranges in size from 1/8 inch to 1.5 inches long. Here is a website with a photo of armyworm: Armyworm photo. For an article on armyworm management please view this site: Armyworm Article
Black Cutworm has also been an issue over the last few weeks. Several Extension educators across the NYS have reported cutworm damage in corn fields. Black cutworm larvae vary in color from light gray to black with a pale brown to black head. Larvae have a greasy, shiny appearance with coarse granules present over their body. For more information on black cutworm view last weeks article: Black Cutworm in Corn Article
Mike Stanyard and Brian Aldrich report cereal leaf beetle
over threshold in small grain fields in
I discovered alfalfa weevil over threshold in alfalfa re-growth in Julie Hansen’s trial plots at SUNY Cobleskill late last week. Tip feeding was at 50% and there were still a lot of small larvae. These plots were sprayed with Warrior. While there is still a mix of small and larger larvae alfalfa weevil in fields I have been looking at scouting should soon end. I am starting to find alfalfa weevil cocoons in a few leaves. The following picture shows what they look like:
This is a good indication that alfalfa weevil feeding by larvae will soon end. Once they pupate (create a cocoon) the leaf feeding by larvae is over.
Currently, potato leafhopper can be found in alfalfa at low levels statewide. Remember, this insect pest infestation levels and increase very quickly. Keep a close eye on this and scout fields weekly.
Dr. Russ Hahn (Crops and Soil Science) suggest that if you have not yet sprayed your weeds in fields of Round-up Ready Corn you should do it soon. Remember weeds should be controlled by the corn’s 4th leaf stage.
Weather Outlook 6/19/08
Temperatures across the state last week ran near or just above
normal, fueled mostly by a very warm start to the week. Nearly all
of the state ended up about 3 degrees above normal, with some isolated
pockets that were as much as 6 degrees warmer than average. Rainfall
was scarce across
Base 50 Growing Degree Days saw moderate accumulation this past
week, with most areas picking up 100 to 150, with slightly more
The area of low pressure that has been giving us cool, wet weather the past few days is forecasted to finally lift out of our region, allowing a return to seasonable temperatures. As this low departs, high pressure to our south will begin to influence our weather tomorrow and Saturday. On Saturday, highs will generally be in the mid 70’s with lows in the mid 50’s. There will likely be some showers and storms around, with a better chance on Sunday as a front comes through. Highs and lows Sunday will each be a few degrees warmer than Saturday. It then appears that this front will stall to our east, with another low sitting over us. However, this doesn’t look like it will give us cold weather like this week. Highs Monday will be in the low to mid 70’s, with mid to upper 70’s Tuesday. Lows will be near 60 both days. With the front and low nearby, occasional rain is likely. As this system departs, highs Wednesday will likely be near 80 with a much lower chance of rain. Most areas during this time period stand a chance at picking up between 1” and 1 1/2” of rain.
Our near normal temperatures look to continue into the 8-14 day period with no big warm ups or cool downs in sight. However, it looks as if precipitation during this time will fall to below average values.
Be Ready for Potato Leafhopper before the damage occurs!
As temperatures increase and weather fronts roll through NY, so does the risk of potato leafhopper populations reaching levels damaging to alfalfa yields and quality. Do you know what to do if a field reaches an action threshold for potato leafhopper in alfalfa? Here are the management options for potato leafhopper in alfalfa!
Option 1: Early Harvest
You can harvest the alfalfa early to control potato leafhoppers if the field is within a week to ten days of a scheduled harvest. By harvesting the alfalfa early, you’ll prevent potato leafhopper from reaching infestation levels that can cause yield and quality loss to the forage. Make sure that the whole field is harvested at the same time. If a field is not clean harvested then the alfalfa that has not been cut will serve as a refuge for potato leafhoppers and can re-infest; thus severely damaging alfalfa re-growth.
Option 2: Use an Insecticide
To protect yield and health of new seedings and established alfalfa, insecticide control can be warranted when a field is not within a week of harvest. For selection of an insecticide consult the current issue of Cornell Guide for Integrated Field Crop Management. Remember to read the label and be aware of blooms, bees and the days until harvest restrictions.
Option 3: Plant Potato Leafhopper Resistant Alfalfa
A third option for control is planting potato leafhopper resistant alfalfa. Obviously, it is a little late for this season’s crop but something to consider for future seedings. Research has shown that potato leafhopper resistant alfalfa is consistently higher in quality than susceptible alfalfa varieties with or without potato leafhopper pressure. PLH resistant varieties yields are comparable and generally better than susceptible varieties when PLH are present. A bonus benefit is that currently available alfalfa varieties with PLH resistance have come down in price over the past several years.
For management information check our on-line IPM guide, Potato Leafhopper on Alfalfa Management Guide
Not too Early to think about Stored Grain Pests
It won’t be long before wheat heads begin to lighten in color indicating harvest time is near. This year’s strong commodity prices prompt much anticipation for a profitable harvest. With that in mind, it is not too early to begin preparing for harvest and checking the readiness of your on-farm storage bins. To maintain the profits a good yield can bring, make and follow a plan to protect the grain while in storage. Remember: Grain storage will not improve grain quality. However, proper management of grain during storage will protect the quality present at harvest.
The IPM approach for stored grain protection includes a combination
of sanitation, well-sealed bins, frequent monitoring for temperature
and insect populations, aeration to cool grain in the fall, and
pest management treatments as needed. Stored grain management begins
with "an ounce of prevention". This article will highlight some
steps one can take now to protect stored grain before it
is harvested. The following pre-harvest information was "gleaned"
whole or in part from Stored Grain IPM information from
Insect infestations are the more common stored grain pest issues one might encounter. Insect infested grain can be docked at time of sale. Most common grain bin insect problems can be traced back to infestations in previously stored material, cracked grain and grain fines and trash. The key to prevention is SANITATION - clean out the bin every time it is emptied. How clean? If you can tell what was stored in the bin the last time it was used, it needs more cleaning. In addition to insects, birds and rodents are also attracted to left over and spilled grain. Lights mounted on or in close proximity to grain bins may attract unwanted stored grain insects.
Who might the likely insect pests be? This could be the subject for a future article. In the meantime the following extension factsheets provide information to help identify the insects you may find as you clean out your storage bins: Management of Stored Grain Insects, Part II. Identification and Sampling of Stored Grain Insects and Principal Stored Grain Insect Pests of Indiana.
The following sanitation practices are recommended for managing
empty storage bins.
Besides keeping grain dry, grain storages should be well sealed for two other basic reasons:
(1) to minimize grain insect entry problems into base and sidewall
In addition, improved insect kill (efficacy), tighter sealed
structures require lower dosage rates, which reduce the cost of
future fumigations and cover the cost for the sealing materials
Source of the above stored grain pest management information: Oklahoma State University Stored Products Research & Education Center Newsletter - Spring 2004 and Purdue's Stored Product Pest factsheet.
Soybean aphids – quiet so far
Soybean planting is nearing completion in many areas of the state with some fields just in early trifoliate stages. So far no soybean aphid reports have surfaced hopefully indicating we are still ahead of that curve.
The bulk of weekly scouting for SBA should begin when soybean
plants are in the late vegetative (pre-reproductive) to early reproductive
(i.e. flowering) growth stages. Of course it is never too early
to begin monitoring for this pest and it is worth a look for them
as you check soybean fields for plant growth and development, plant
population and weed presence and information to time management
decisions. Monitoring soybeans for soybean aphids is easy. The following
protocol is recommended:
Note: Current research data suggests that treatment during vegetative soybean growth stage is not likely to result in an economic return. In most cases, weekly scouting will be necessary for 8-10 weeks.
We will continue to keep close tabs on potential soybean pest problems and share any pertinent updates in future weekly pest reports. A national perspective on soybean aphid and soybean rust information can be found at the USDA Public PIPE website.
Which is Corn Rootworm?
Have you ever gotten western corn rootworm confused with the striped cucumber beetle? Do you know the difference between corn rootworm and striped cucumber beetle? Striped Cucumber Beetle and Western Corn Rootworm look similar but are two different species of insects.
Striped Cucumber Beetle, Acalymma vittatum
Western Corn Rootworm, Diabrotica virgifera virgifera
Learn more about the differences between Western Corn Rootworm
and Striped Cucumber Beetle:
NYS 2008 Asian Soybean Rust Status
Sentinel plots in
Since the beginning of 2008, soybean rust has been reported on
kudzu in one county in
NY State Soybean Rust Hotline: 607-255-7850
Alfalfa Weevil Prediction for NYS – the end is near?
Current accumulated degree day data indicates alfalfa weevil populations are approaching maturity and should not be an issue much longer this season. However…. Alfalfa weevil damage continues to be reported on alfalfa re-growth in some areas of NYS. Lingering concerns over alfalfa weevil are the result of delayed population development affected by the cooler temperatures many areas experienced earlier this season. So in addition to monitoring for PLH on alfalfa re-growth, also continue monitoring for signs of weevil feeding. See: IPM for Alfalfa Weevil for more information on monitoring late season alfalfa weevil.
As of March 1 - June 18, 2008
Stage or Event
Accumulated growing degree days (48F base temperature)
(Note: for alfalfa weevil predictions use Base Temp of 48F)
* 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 winter annual and other early season weeds, any patches of herbicide resistant weeds?
* Determine plant populations, make notes on emergence problems, growth stage
* Gaps in row? Check for seed corn maggot, wireworm, cutworm, armyworm, seedling blights, birds, seed placement issues
* Check no-till fields/fields with high residue or weeds for slug damage, cutworm, armyworm
* Monitor for weeds, note presence of "who", "how many" and "where"
* Check herbicide resistant corn fields for herbicide resistant soybean
* Adjust post emergence weed control actions
* Monitor winter grains for crop stage (flag leaf?), insect problems (cereal leaf beetle, armyworm) and foliar / head diseases
* Evaluate crop for adequate stand and plant vigor
Alfalfa & Hay:
* Monitor alfalfa seedings for weeds, insects & diseases.
* Check regrowth of established alfalfa stands for alfalfa weevil, potato leafhopper, weed and disease problems.
* Check windrows of recently harvested alfalfa for signs of alfalfa weevil feeding damage and weevil life stage (instar , cocoon).
* Evaluate stand emergence - seedling blights, seed corn maggot, weed assessment, soybean aphid
* Check herbicide resistant soybean fields for herbicide resistant corn
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 waterers, drainage, roof gutters for leaks and potential overspill
* Begin fly monitoring: install "3X5" index card fly speck monitoring cards through out barn
* Order fly management materials: fly tapes, insecticide baits, natural enemies (parasitoids)
* Continue release of purchased natural enemies (fly attacking parasitoids)
Dairy Livestock Pasture Fly Management:
* Begin monitoring for face fly, horn fly, and stable fly populations
* Check water sources, forage available on pastures
* Check areas near watering troughs, outside feed bunks for evidence of fly breeding. clean as necessary and / or possible
* Keep areas around storage bins and silos clean and mowed
* Evaluate storage bin condition, clean as necessary preparing bins to accept upcoming harvest
* Note any repairs needed for recently used equipment: tractors, tillage implements, planters, etc. as they are cleaned and serviced.
* Service corn and soybean planter as needed. alfalfa harvesting equipment, and tillage implements
* Calibrate manure spreaders - maintain records on amount spread per field
PESTICIDE EMERGENCY NUMBERS
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.
Seed Growers Field Day
*Tuesday July 8
Weed Science Field Days
*Wednesday, July 9, 2008
Valatie Research Farm
9:30 am - Noon
*Wednesday, July 16, 2008
Robert B. Musgrave Research Farm
1:30 pm - 5 pm
Wednesday, July 23, 2008
Robert B. Musgrave Research Farm
Aurora, NY (
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