Weekly Field Crops Pest Report 2007

View from the Field

Ken Wise
NYS IPM

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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 (Northwestern NY) reports finding low levels of soybean aphids in some fields.

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 ( Madison County) reports PLH numbers remain at low infestation levels in alfalfa this week.

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 ( Lewis County) also reports an infestation of armyworm in no-till corn. Patricia Westenbroek ( Sullivan County) states she is finding armyworm in the 2^nd and 3^rd instar in grass fields and corn but infestation levels remain low at the moment.

Jeff Miller ( Oneida County) reports finding low levels of Fusarium Head Blight in winter wheat fields. Gary Bergstrom adds Fusarium Head Blight (FHB) disease incidence appears to be low so far this season with less than 2% of heads showing symptoms in most wheat fields across the state.  The first detections for 2008 of leaf rust of wheat were made this week at Ithaca and Aurora.  Wheat is generally at the kernel milk to soft dough stages of development.  The frequent rains have been conducive for deposition of rust spores transported in air masses originating from rust-infested areas to the west and south of New York.  It is recommended that wheat fields be monitored over the next week for leaf rust incidence (percentage of plants showing any rust) and severity (percentage of the flag leaf area covered by rust on those plants that show rust).

Jeff Miller also reports that last week he was in fields of alfalfa that were over threshold for alfalfa weevil in 2^nd cutting. While alfalfa weevil normally is keep in check with the 1^st cutting this year several extension educators have reported alfalfa weevil over threshold in 1^st and 2^nd 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

Drew Montreu
NOAA NE Climate Center, Cornell University

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Weather Outlook 2.26.08

Summary:

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 the Lake Ontario shore and Adirondacks picking up less than an inch.

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, with the Adirondacks and Catskills as much as two weeks behind. Despite this, the number of growing degree days so far this year is still up to a week ahead of normal.

Forecast:

A stormy period in the weather is ahead of us for the next week or so. A warm front will stall out over Northern New York early this weekend before a cold front comes through Saturday. Highs Saturday will be generally near 80, with lows in the mid 60’s with numerous showers and thunderstorms. The front will not go far, however, and showers and thunderstorms will continue into Sunday, with highs in the mid to upper 70’s. The front will continue to sit near the Eastern Coastline for Monday, Tuesday and even into Wednesday. As areas of low pressure move along this front, they will spread more rain and thunderstorms across the state, especially Monday and Tuesday. With the front to the south, clouds and rain, highs will be in the low to mid 70’s Monday, with low to mid 70’s on Tuesday. With less of a chance of rain on Wednesday, highs should reach near 80. Lows all three days will range from near 60 to the mid 60’s. With the high probability of rain most days during this period, it appears possible that some hefty rain totals are possible. The latest projections show a possibility for widespread totals of 2”, with localized areas getting more. Looking out 8-14 days, it appears that temperatures and precipitation will both return to near normal levels.

Lady Beetles in Field Crops

Ken Wise
NYS IPM

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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), introduced from Europe, is also an effective predator of aphids. A single larva can consume 800 to 1,000 aphids and an adult will eat from 3,000 to 4,000 aphids during its lifetime. This is a large lady beetle and is 7-8 millimeters.

The pink-spotted Lady Beetle (Coleomegilla maculata) is native to North America and is very abundant in the Northeast. Adults can consume 50 aphids per day, while larvae can eat 10 to 25 per day. The pink-spotted lady beetle will consume plant pollen that may constitute up to 50% of the diet. This is a medium sized lady beetle at 5 to 6 millimeters.

The spotted Amber Lady Beetle (Hippodamia variegate) was introduced from Europe. Depending on the Hippodamia spp. and the larval instar, this beetle may consume about 25 aphids per day. Adults can eat as many as 50 per day depending on Hippodamia spp. This lady beetle is small and only 4 or 5mm.

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.

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 North America. Some people think it was transferred on a ship in the St. Lawrence Seaway sometime in the late 1960s. This lady beetle does feed on aphids but I found no information on the amount they can consume. This is a small beetle that is only 4 to 5 millimeters.

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?

Ken Wise
NYS IPM

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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

Keith Waldron
NYS IPM

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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 Northeast US commercial insectary offering the dairy fly parasitoids (Muscidifurax raptor and Musicifurax raptorellus).

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

Ken Wise
NYS IPM

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Mike Dennis (Seneca County) reports this week that he was finding a good population of dung beetles in manure pats in rotational pastures. Last summer I worked on a project with Dr. Don Rutz in Veterinary Entomology at Cornell University where we are looking at the diversity of dung beetles in cattle pats in NYS. Dung beetles are very important insects that help decompose cattle manure in pastures. Dung beetles compete with other organisms like flies inside the cattle pat for resources within the manure, thus limiting pasture fly development. There are three types of dung beetles in a cattle pat:

Rollers (telecoprids)
Geotrupes species, form balls of manure which they push from the pat to bury as brood balls

Tunnelers (paracoprids)
Onthophagus species are tunnelers that consume the pat and burrow beneath it to bury brood balls. 

Dwellers (endocoprids)
Aphodius species, consume the manure as they tunnel within the dung pat and oviposit eggs in the manure or surrounding soil.  Most dung beetles found in NY are dwellers.

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

Gary Bergstrom
Cornell University

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United States Soybean Rust Commentary (updated: 06/20/08)
Soybean rust was confirmed in Taylor County, Florida, on kudzu on June 20th. This is the first find in that county in 2008. Since the beginning of 2008, soybean rust has been reported on kudzu in one county in Alabama; eleven counties in Florida (two of these counties had reports on coral bean and snap bean, and one county had a report on soybean); three counties in Louisiana; one county in Mississippi, and three counties in Texas. Reported infected kudzu sites in many counties have been destroyed. Rust was also reported in three states (5 municipalities) in Mexico on yam bean and soybean. These too have been destroyed or are no longer active, except for the find in Chiapas.

NY State Soybean Rust Hotline: 607-255-7850

NYS Soybean Rust Website

USDA Soybean Rust Website

Clipboard Checklist

Keith Waldron
NYS IPM

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General:

* 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?

Field Corn:

* 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

Small Grains:

* 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?

Soybeans:

* 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

Storage:

* Keep areas around storage bins and silos clean and mowed

Equipment:

* 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

Upcoming Events

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Seed Growers Field Day
*Tuesday July 8
NYSIP Foundation Seed Barn
Cornell University, Ithaca, NY

Weed Science Field Days
*Wednesday, July 9, 2008
Valatie Research Farm
9:30 am - Noon
Valatie, NY ( State Farm Road off Route 9 just north of Valatie)

*Wednesday, July 16, 2008
Robert B. Musgrave Research Farm
1:30 pm - 5 pm
Aurora, NY ( Poplar Ridge Road, connects 90 and 34B)

Aurora Field Day
Wednesday, July 23, 2008
Robert B. Musgrave Research Farm
Aurora, NY ( Poplar Ridge Road, Connects 90 and 34B)

Contact Information

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Keith Waldron: NYS Livestock and Field Crops IPM Coordinator
Phone: (315) 787 - 2432
Fax: (315) 787-2360
Email: jkw5@cornell.edu

Ken Wise: Eastern NYS IPM Area Educator: Field Crops and Livestock
Phone: (518) 434-1690
Fax: (518) 426-3316
Email: klw24@cornell.edu