Weekly Field Crops Pest Report 2008
View from the Field
I was in 4 soybean fields last Friday (6-20-08) that seem to have a disease on every plant in all 60 acres near Melrose, NY (Just north of Troy). Some leaves looked like bacterial pustule and others looked somewhat like Downy mildew? Dr. Gary Bergstrom and the Cornell University Plant Disease Diagnostic Clinic suggest it is most likely bacterial pustule and/or environmental stress or other factors causing the symptoms.
I also detected 2 soybean aphids in the fields. Mike Stanyard
Potato leafhopper (PLH) was under threshold in 10+ inch alfalfa
at the Cornell Research Farm at Valatie. Adult PLH numbers were
under threshold (110 PLH in 7 samples) and no nymphs were found
in the field. Expect populations and damage risk to increase once
we start to see PLH nymphs. Kathe Evans (
Armyworms seem to be taking center stage again this week. Mike
Stanyard reports local infestation levels have been high with fields
receiving treatment. He suggests focusing attention on scouting
corn because wheat is starting to dry down and is not as attractive
to armyworm. Mike is also starting to find tachinid fly parasitoids
and a virus disease on many armyworm larvae, indicating biological
control is beginning to have an impact on local populations of this
pest. Joe Lawrence (
Jeff Miller (
Jeff Miller also reports that last week he was in fields of alfalfa that were over threshold for alfalfa weevil in 2nd cutting. While alfalfa weevil normally is keep in check with the 1st cutting this year several extension educators have reported alfalfa weevil over threshold in 1st and 2nd cutting. The good thing is that enough growing degree days have accumulated to force alfalfa weevil larvae to pupate thus, ending this season’s issues with this pest.
Weather Outlook 2.26.08
Temperatures during the last 7 days were a few degrees below
normal, with about a 3 degree departure from normal on average.
Precipitation was around an inch in most locations, with areas along
Base 50 growing degree days this past week saw low accumulations
once again, with most areas only receiving 75-100. The higher elevations
around the state only saw 50-75. For the year, there have 600-800
growing degree days for the lower elevations, with 300 to 500 in
the mountains. This puts most of the state a week behind last year,
A stormy period in the weather is ahead of us for the next week
or so. A warm front will stall out over
Lady Beetles in Field Crops
I am starting to see many different species of lady beetles in corn and alfalfa. Many of these lady beetles are predators of aphids and other pests. Because of lady beetles and other predators aphids are generally not a problem in field crops in NYS (exception: Soybean Aphids can become a problem) like they are in other parts of the country. Here is a list and photos of lady beetles I have found in alfalfa this year.
While the Multicolored Asian Lady Beetle (Harmonia axyridis) can be an annoyance to some home-owners by getting in their houses in the fall, they are an effective predator of aphids. An adult is capable of consuming 100 to 270 aphids per day, and each larva can consume 600 to 1,200 aphids during its development. This lady beetle is oval and convex and is about 6 millimeters. Coloration varies from light orange to red, and the number of spots vary with this lady beetle.
The seven-spotted Lady Beetle (Coccinella septempunctata),
The pink-spotted Lady Beetle (Coleomegilla maculata)
is native to
The spotted Amber Lady Beetle (Hippodamia variegate)
was introduced from
The parenthesis Lady Beetle (Hippodamia parenthesis)
is native to
The fourteen Spotted Lady Beetle or the Cream Spotted Lady-beetle
(Propylaea quatuordecimpunctata) is a European lady beetle.
This lady beetle was accidentally introduced to
The 9-spotted lady beetle?????
What Happened to the Official NYS Insect?! Help us find it! Check out “The Lost Ladybug Project” at the following website: The Lost Ladybug Project
What Fields are at Risk for Corn Rootworm?
Corn rootworm populations can build in a cornfield from year to year. Fields that are not rotated and remain in corn for several years are most at risk from corn rootworm damage. A two to three year rotation out of corn or cucurbits such as pumpkins reduces the risk that a corn field will reach an action threshold for this pest. This spurs the question, “Do you scout a 1st year cornfield after sod for corn rootworm?” Yes, because any pollinating cornfield can attract corn rootworm. Even worse, late pollinating corn can attract many hungry corn rootworm beetles from fields where they did not get enough pollen. After the beetles eat their fill on late season pollen they will lay eggs in the soil. So yes, scout all cornfields for corn rootworm that will be planted to corn again next year. You do not need to scout fields that will be rotated out of corn next year. For more information on corn rootworm checkout our online publication: Corn Rootworm Management Guide: Corn Rootworm Management
Curb conditions that can favor dairy barn fly populations
Confined livestock facilities can contain perfect habitats for house and stable fly populations to develop. The good news is these conditions, when controlled, can help minimize 90% or so of the potential fly problem. A little management time each week will pay big dividends as the season progresses.
Sanitation, Sanitation, Sanitation! Staying ahead of fly populations begins with cultural practices that eliminate conditions favorable to fly breeding. House flies and stable flies both breed in areas where moist undisturbed organic matter such as spilled feed, moist hay, wet grain, and manure-soiled bedding are present. Another favorable breeding spot is a location that remains relatively undisturbed and offers protection from foot and hoof traffic. Frequent clean out of potential breeding sites and other activities that enhance dry conditions in animal areas will make the local environment inhospitable to successful buildup of fly populations.
With sound sanitation as the foundation for fly management, additional tactics can be brought to bear. A variety of biological control agents occur naturally in the typical dairy barn. These include various predators of house and stable fly eggs, larvae and adults. When sanitation, are used effectively, natural enemies can more easily keep up with what fly populations remain and can be quite effective at reducing their numbers. The key is to employ sound sanitation, early and as often as practical, as the first line of defense for mitigating fly populations. Common fly predators include predaceous mites, rove and Carcinops beetles, parasitoid wasps, and fly diseases. Parasitoids, the small wasps that attack fly pupae, are quite effective at reducing fly populations. These tiny wasps, however, can take up to three times longer to develop than the house fly. This is the reason their populations can use a “jump start” early in the season to reach the numbers needed to head off house fly problems. For those wishing to use parasitoids to enhance their biological control efforts the earlier in the season the better is recommended. There is still time to begin releasing the wasps in barns and calf housing areas. Parasitoids should be released close to their prey, i.e. in and around potential fly breeding habitat.
A number of insectaries advertise house fly parasitoid species for use in confined animal facilities. Our experience at Cornell has shown a need to obtain climatically adapted strains.
The source of parasitoids we have worked with in our area is
IPM Laboratories in Locke NY. (315.497.2063). To the best
of my knowledge this is the only
If producers are interested in trying a source from outside the NE, it is strongly recommend that they ask the supplier “Is the parasitoid they are purchasing climatically adapted to the northeast?” We are still in the relatively early stage in our understanding of how to use biocontrol to full advantage in fly management programs. Should producers purchase a product from outside the NE, we would be very interested in their thoughts and feedback on how well it is working for them.
To help evaluate how well fly management efforts are working use some means, such as spot cards, to monitor fly populations over time. The spot card method helps provide an objective means to gain information and feedback on the effectiveness of their overall fly management program. Spot cards are 3X5 index cards placed at 5-10 locations throughout the barn in areas where flies can be seen resting such as walls, rafters, poles, etc. Date and identify the location (number) of the card and install cards out of the reach of animals. Change the cards weekly. Our guideline has been 100 spots per card per week indicates a fly problem. Your threshold may be different – the important thing to consider is to have a reference point on which to compare populations over time. Search the area close to location of the card for fly breeding habitat. Clean as necessary. Watch and compare spot card counts the following week.
Reducing the number of adult (breeding) flies helps minimize the potential for fly population buildup. Two additional fly management tactics to curb fly numbers include use of sticky ribbons and tapes and insecticide baits. Sticky ribbons (including the wide roll types) and tapes offer an effective non-toxic means to capture adult flies. Place tapes in areas not at risk from high winds, turbulent air and dusty conditions, Insecticide : sugar bait stations can also be deployed to capture adult flies. For more information on IPM for barn fly management see: Integrated Management of Flies in and around Dairy and Livestock Barns and Pest Management Recommendations for Dairy Cattle.
Dung Beetles in your Pastures
Mike Dennis (
Many cattle are given an insecticide for fly control on pasture that are not always completely metabolized in the body and is dispelled into the manure pat, thus killing some dung beetles. Try to select fly control methods and products that help preserve dung beetles your pastures.
NYS Soybean Rust Update
NY State Soybean Rust Hotline: 607-255-7850
* 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 (grain maturity), 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).
* Storage areas cleaned and ready to accept upcoming harvest?
* Evaluate stand emergence - seedling blights, seed corn maggot, weed assessment, soybean aphid
* Check herbicide resistant soybean fields for herbicide resistant corn
Dairy Cattle: 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 Cattle: Pasture Fly Management:
* Monitor animals for presence of face flies, horn flies and stable flies.
* 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
* Keep areas around storage bins and silos clean and mowed
* 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
Seed Growers Field Day
Weed Science Field Days
*Wednesday, July 16, 2008
Keith Waldron: NYS Livestock and Field Crops IPM Coordinator