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NY Weekly Field Crop Pest Report, 2005

June 10, 2005 Volume 4 Number 8

1. View from the Field

2. Soybean Aphid Season Opener

3. Potato Leafhopper has Arrived

4. Corn Skips and Flying Pests

5. Are Slugs a Threat to Corn and Soybeans this Year?

6. Growing Degree Days in NYS

7. Clipboard Checklist

8. Upcoming Meetings

9. Contact Information

View From The Field

Western NYS
Julie Stavisky, NYS IPM

Eastern NYS
Ken Wise, NYS IPM

Keith Waldron, NYS IPM

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The potato leafhopper challenge lead to some heated competition this year! And the winner is... Nancy Glazier (NWNY Team)! Nancy found PLH on Saturday, June 4th. Since then, reports from several locations in the state confirm the arrival of PLH in alfalfa (Genesee County, Oneida County, Ontario County). There are no reports of nymphs yet.

Following the first report of soybean aphid on soybean plants from Orleans County on Tuesday June 7th, a flurry of reports have come in. SBA has been seen on soybeans in Cayuga County, Ontario County, Genesee County, and Wayne County. I found nearly as many ladybugs as plants with SBA in one field in Wayne County.

The hot, dry weather seems to be favorable for cereal leaf beetles. Mike Stanyard (NWNY Team) has received many reports of CLB in Wayne County. So far, they are below threshold on wheat and spring oats. CLB have been reported to be prevalent in Cayuga County, too.

While having an Organic Wheat and Soybean TAg meeting in Essex County this week we discovered powdery mildew on hard white winter wheat. About 80% of the plants were infected and 70% of the flag leaves were covered with the mildew. Organic soybean fields were starting to get both annual broadleaf weeds and perennial grasses (Quack). The producers were planning on blind cultivating the fields before the beans were in the hook stage with a rotary hoe and tine weed at the fourth leaf stage. They are also planning on row cultivating for the quackgrass that was starting to emerge in the fields.

First sightings of fireflies aka lightning bugs observed in several central NY counties late last week. Why noteworthy for field croppers? Fireflies are generally first observed about the same time that corn rootworm (CRW) eggs begin to hatch. So for your continuous corn fields…..be on the lookout for signs of CRW feeding on young (knee high) corn over the next several weeks. First clue that CRW may be causing problems a hard to explain symptom of drought stress. IN this case dig plants and check roots for damage.

Aside from being visible in NY summer nights…. What else do you know about fireflies? Friend, foe, neutral? According to The Firefly Files: “Firefly larvae are predaceous and have been observed feeding mostly on earthworms, snails and slugs. Larvae can detect a snail or slug slime trail, and follow it to the prey. After locating their future meal, they inject an anesthetic type substance through hollow ducts in the firefly's mandibles into their prey in order to immobilize and eventually digest it. Multiple larvae have also been observed attacking large prey items, such as large earthworms. Other observations suggest larvae sometimes scavenge dead snails, worms and similar organic matter.” Who knew?

See also - Fireflies – Nominated for the State Insect of Indiana?

Soybean aphid season opener

Julie Stavisky, NYS IPM

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Soybean aphid season is here! Last week, soybean aphids were seen on buckthorn, the local overwintering host. This week, they’ve been observed in soybean fields.

Soybean aphids can give soybean fields the 1-2 punch, since not only are the aphids that spent the winter here a threat, weather patterns can deposit huge numbers of aphids in a very short time.

How will you know when soybean aphids are present in soybeans? Look carefully at the undersides of soybean leaves. The aphids are usually seen in small clusters near the leaf veins. They are tiny, 1/16” long at their largest, with distinctive black cornicles (tail pipes). Soybean aphids are the only aphids to successfully colonize soybean plants.

During early to mid-vegetative stages of soybean growth, economic benefit from insecticide application is not likely. Plus, using an insecticide too early in the season may jeopardize the establishment of natural enemies in the field. When scouting the early vegetative stages of soybeans for soybean aphid, it is just as important to watch for the aphid’s natural enemies, including ladybugs, syrphid fly larvae, parasitic wasps, and fungal pathogens. We’ll highlight these biological control agents over the next several issues of the Pest Report, so stay tuned! During late vegetative stages and early R stages, the economic threshold is 250 aphids per plant, though this only holds true if aphid populations are still on the rise.

There is a new tool this year from the University of Minnesota that deserves our attention. The SAGE model, or Soybean Aphid Growth Estimator, makes a prediction about how fast aphid populations may build up in soybeans given aphid density per plant and high and low temperatures for today and the next 6 days. For more information, check out MN Soybean Production

Potato Leafhopper in New York

Ken Wise, NYS IPM

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Potato leafhopper has been discovered in Western and Central NYS. While they are at very low numbers potato leafhopper populations can build very quickly with the very warm weather we have recently received. Do you know what potato leafhopper looks like? Remember adults are bright lime green, 1/8 inch long and can fly. Potato leafhopper nymphs are yellowish-green and look similar to the adult but do not have wings. More to come on next week’s issue!

For management information on potato leafhopper check our on-line guide: Potato Leafhopper on Alfalfa Management Guide,

Corn Skips and Flying Pests

Keith Waldron, NYS IPM

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I have had a few calls (Caws) lately regarding bird damage to field corn. Crows and geese to be more specific. Newly emerging corn seedlings must be very tasty this time of year, and wheat a close second.

Remember to watch for BIRD damage in your monitoring activities. Crows, geese, blackbirds and turkeys like to feed on seed and newly emerging plants. Empty places in corn field rows? Skips in the field, missing plants, excavated areas within the row, feathers, tracks and evidence of "avian fertilizer"....

A few recommendations for minimizing bird problems in field crops follow.
The biggest losses in corn at this time of year are often from crows, which pull up seedlings and can decimate a field of young corn.

Paul Curtis says "Turkeys get a bad rap for pulling corn." Paul notes that studies in Iowa, Wisc. show turkeys primarily take insects and grit in the fields. Being conspicuously large and visible during the day, turkeys get blamed for pulling corn. A case of being in the wrong place at the right time....The Midwestern studies show that growers have a hard time telling turkey damage from small mammal damage. Most corn pulling in Iowa was due to squirrels in the field around dawn and dusk. Growers did not see the squirrels and hence blamed the turkeys.

Cost-effective, safe, and neighbor-friendly options for repelling crows and other birds have been limited, but there are some reasonable options. The most common, inexpensive, and easy methods are designed to frighten birds away.

The following information has been adapted from discussion with Paul Curtis (Cornell Dept. Natural Resources) and an article by Ruth Hazzard, UMass Cooperative Extension. Ruth's remarks regarded bird management in sweet corn but may have utility for our field crop settings.

Scary Noises.Propane cannons may provide some relief by scaring them, however crows, geese, blackbirds and turkeys can adapt to the sound and one should consider community relations when installing a source of regular "Ka-Booms".

Repelling devices include recordings of distress calls or predatory birds, visual deterrents such as scare-eyes or shiny tapes, and exploding devices such as shellcrackers and cannons. Often, birds are most effectively repelled by a combination of types of devices. Paul reports success with an electronic bird distress call device ("Bird Gard") in controlling blackbirds in ripening sweet corn fields. It probably would work well for corn sprouts also. Paul says he has not tried it with crows. He adds that geese ignore the device in suburban areas near ponds.

Some sources of auditory and visual frightening devices are: BirdBusters 300 Calvert Avenue, Alexandria, Virginia 22301 1-800-NO-BIRDS (662-4737) or 1-703-299-8855 Fax: 703-299-0844. Bird-X, Inc, 300 N. Elizabeth St., Chicago, IL. 60607 U.S.A. 800-662-5021 or 312-226-2473. Gemplers' : GEMPLER'S, P.O. Box 44993, Madison, WI 53744-4993, 1-800-382-8473.

Planter/Planting Time Details: Pay close attention to planter settings for depth and seed slot closure, planting at a higher population on fields where bird feeding is anticipated. Calibrate planters and check plant populations after emergence.

Bird seed/feed alternatives: Set out alternative or decoy foods for birds. Paul Curtis suggests using milo/millet as an alternative food for birds. Milo/millet is less attractive to deer than corn. Also, be aware that it is illegal to bait deer anywhere in NYS, so if deer use the bird feed growers will have to stop putting it out.

Scary Shiny Objects: Reflective bird tape that is silver on one side and red on the other can be twisted and suspended about 6 inches above the newly seeded rows. A field full of this shiny tape will disorient bird and grower alike. Mylar tape has worked well for some bird species, but the area that can be treated is limited. It breaks easily in high winds, and probably has limited application in commercial fields (but is good for home gardens).

A method that is sometimes discussed in the literature is a bird-scare balloon with shiny, mylar "eyes," or inflatable owls. In Paul's experience, these techniques have not been of much value for most fruit and vegetable crops.

Really, really scary option Paul suggests another, new on the scene, combination option: the "Scary-Man Fall Guy". You gotta love the name.. It has noise and an inflatable human effigy. It seems to work well in aquaculture situations. Trials are needed in grain crop situations. Paul expects that crows and turkeys would avoid this device, but it is expensive. Check out their web site: Inflatable Scarecrows. No really. check out the website.. Could add interesting ambiance to your neighborhood at Halloween time!

Vertebrate problems a concern for your producers? You may be interested in a new website Paul Curtis and NYS DEC have launched : Best Practices for nuisance wildlife control operators: A training manual. The site is at: http://nwco.net/. This site contains the electronic version of a training manual created by the New York State Department of Environmental Conservation and Cornell University.

American crow (Corvus brachyrhynchos)
Best Practices: American Crow
Wildlife Damage Management Fact Sheet Series: Crows

Canada geese (Branta canadensis, several races)
Best Practices: Geese
Note: the product list in this article is definitely not exhaustive; inclusion in this list does not imply product endorsement nor does exclusion imply lack of endorsement.

Applying any of the suggestions in field crop settings? Likely implementation depends on the severity of the problem, local practicality, and ability of the producer to respond. Any thoughts or additional suggestions from the field are welcome.

Thanks to Paul Curtis and Lynn Braband (NYS/IPM) for their suggestions.

Are slugs a threat to corn and soybeans this year?

Julie Stavisky, NYS IPM

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Reports are in from Ohio that slugs are hitting corn and soybean fields. Problems were widespread in soybeans in NY last year, and the threat for this year’s crops may be just around the corner.

Slugs spend the winter as eggs. The overwintering eggs are usually laid in the general area where slugs were feeding the previous spring, summer, and fall. Thus, if they were a problem in an area last year, there’s a good chance they will be back for more. Slugs will attack seedlings and lower leaves, leaving coarse, irregular holes and characteristic “slime trails” in their wake. Feeding may result in serious injury and even stand reduction under severe infestations.

Slugs prefer cool and moist conditions, and they thrive when there are hideouts in the field, such as in the cover provided by debris on the soil surface. Slugs tend to feed most when temperatures are in the mid 60’s. Stand reduction problems have typically been worst during wet, cool springs. Will this hot, dry spell slow down the slugs? So far, slugs have not been seen as much this year as they were last year, though we should continue to watch soybean and corn vigilantly. At highest threat are no-till soybean fields where slug problems occurred last year.

Growing Degree Days in NYS

Keith Waldron, NYS IPM

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March 1 - June 7, 2005


Base 48 F

Base 50 F







Clifton Park















* Missing data

Source: http://newa.nysaes.cornell.edu/base5005.htm

Clipboard Checklist

Keith Waldron, NYS IPM

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• Maintain crop production activity records by field, including harvest date, pesticides used, nutrient inputs including manure, etc.

Established Alfalfa and Hay:

• Finish hay harvesting and storage

• Take alfalfa stand counts if not done earlier in the season.

• Monitor stubble for alfalfa weevil treat if necessary.

• Begin Potato leafhopper monitoring

• Monitor fields for weeds and diseases: record information on type and location for future cropping decisions.


• Evaluate weeds and adjust post-emergence treatments

- Cultivate or treat if necessary

• Monitor insects (cutworm, rootworm, wireworm, etc.), slugs, and foliar diseases (anthracnose leaf blight, eye spot, gray leaf spot, etc.)

• Pre-Nitrogen Sidedress Soil Test and apply sidedress as needed


• Evaluate stand for emergence issues, plant population

• Begin to monitor for soybean aphids, soybean rust

Small Grains:

• Check condition of flag leaf for cereal leafbeetle and foliar (and head) diseases

• Winter Wheat expected to be heading and flowering stages

• Spring grains expected to be in jointing and stem elongation stages - continue scouting for powdery mildew and cereal leaf beetle


• Adjust rotation


• Insecticidal ear tags for heifers on pasture

• Manure management and initiate release of biological control agents (parasitic wasps) for house fly and stable fly control in confinement facilities.

• Check condition of pastures and animals on pastures

- Adjust pasture rotation as necessary

- Evaluate need for face fly and stable fly control measures


• Note any repairs to harvesting equipment as they are cleaned and lubricated.

- Repair forage harvest equipment as needed

• Prepare small grain combining equipment or arrange for custom combining

• Check grain handling and storage equipment, augers, bins, fans.


• Plan ahead for a vacation. Summer (like life…) is short. All work and no play

Upcoming Meetings

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July 6 ­ Wednesday ­ NY Weed Science Field Day, Valatie Research Farm. Valatie, NY (State Farm Road off Route 9 just north of Valatie)

July 7 ­ Thursday ­ Seed Growers’ Field Day, NYSIP Foundation Seed Barn, Ithaca, NY (791 Dryden Road, Route 366)

July 13 - Wednesday ­ NY Weed Science Field Day, Robert B. Musgrave Research Farm, Aurora, NY (Poplar Ridge Road, connects 90 and 34B)

July 14 ­ Thursday ­ NY Weed Science Field Day, H. C. Thompson Research Farm, Freeville, NY (10 miles Northeast of Ithaca, Fall Creek Road, Rt. 366 extension)

July 15 ­ Friday ­ Aurora Field Day, Robert B. Musgrave Research Farm, Aurora, NY (Poplar Ridge Road, connects 90 and 34B)

Contact Information

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Julie Stavisky:IPM Area Educator, Livestock and Field Crops, Western NY
Phone: (315) 331-8415
Fax: (315) 331-8411
Email: js38@cornell.edu

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