Skip to main content
link to field crops section
->Home > fieldcrops > tag > pestrpt > pestrpt09

Weekly Field Crops Pest Report 2009

July 31, 2009                       Volume 8 Number 15

1. View from the Field

2. Weather Outlook July 30, 2009

3. Pollen Islands will Attract CRW

4. Partial Alfalfa Field Harvest Increases PLH risks

5. Soybean Rust Update

6. Clipboard Checklist

7. Mark Your Calendars

8. Contact Information

View from the Field

Ken Wise

return to top

Soybean Aphid (SBA) continues to be a problem in soybean fields across New York. There are many reports from County Extension Educators confirming there are several soybean fields over economic thresholds. When you scout SBAs make sure to count aphids on2 plants in each of 10 random locations (20 total plants) in the field. The economic (action) threshold for SBA is an average of 250 aphids/plant. If you reach the 250aphids per plant average you have 5 to 7 days to control this insect pest. If you see a lot of predators in the field like lady beetles, lace wings and more, they do a great job at keeping the population of aphids under control. When you are close to the threshold watch the population of aphids for a few days to see if the predators might lower the infestation level of SBA.

Weather Outlook July 30, 2009

Drew Montreu
NOAA Northeast Regional Climate Center

return to top

A change in the weather pattern last week allowed for temperatures to be a couple degrees above average statewide for the first time all season. Precipitation totals, which do not include yesterday's rain, where generally less than an inch. Western New York and the Hudson Valley got between1 and 2 inches of rain. Rainfall from yesterday is not yet available.

Base 50 Growing Degree Days accumulated 125 to 150 in most areas, with a couple locations getting into the 150 to 175 range. The higher terrains saw less. Compared to last year, everywhere is 7 to 14 calendar days behind, with a couple isolated pockets even further behind than that. Compared to normal though, most areas are no more than 7 calendar days behind, though some areas of the Tug Hill region and Western Finger Lakes are a bit further back. Southeast of I-88, there are even a few pockets that are a day or two ahead of normal.

A relatively dry period in the weather can be expected for the next week, with really just 2 instances of rain to worry about. One of those will come overnight tonight and into tomorrow, as another low pressure moves by. Today will be wonderful though, with plenty of sunshine and highs near 80. After tomorrow's rain, Saturday will end up a lot like today, with sun and highs near 80. A frontal system will approach later Sunday and move through overnight and early Monday for the second best chance of rain this week. Most places should stay dry during the day Sunday though, with highs into the low to maybe mid 80s. I feel like Monday afternoon may end up nice too for the western regions, with showers tapering off in the east and highs near or a bit above 80. High pressure will build in for Tuesday and Wednesday, with no big weather concerns either day. Highs both days will end up in the low 80s.Low temperatures throughout the period should range from the upper 50s to mid60s, with the warmest nights coming tonight and Sunday night. Over the next 5days, most areas should see less than three-quarters of an inch of rain, with many locations seeing less than even a half an inch. For the 8 to 14 day forecast, cooler weather will try to come back, with the Climate Prediction Center showing a slight chance for below normal temperatures and near average precipitation. My general feeling is that if it does end up below average during that period, it will only be a little below and not a big cold spell like earlier this summer.

Pollen Islands will Attract CRW

Keith Waldron

return to top

Remember those corn fields that had troubles with uneven emergence, ponding, compaction, fertilizer, herbicide, or other planting time issues? Drive by many of these fields this week and their up and down plant height patterns look more like a side view of a crazy roller coaster ride than the ideal production field. And now watch the pattern of tassel emergence.  Whatever the reason for the uneven stand its effect on corn rootworm ( CRW) populations can be very predictable.  CRW beetles are pollen feeders and will zero in on plants producing pollen. So in fields with large differences in corn maturity expect that CRW beetles will ?head to the islands? of pollinating corn. In fields of uniform crop growth stage, CRW egg laying is reasonably well distributed. (Recall that CRW females are capable of producing eggs about 3 weeks after they emerge) In the case of the pollen island fields, CRW egg laying may be expected to be more concentrated in the areas where the pollen (food source) is. You can also expect that the highly mobile CRW beetles will follow the pollen sources from clump to pollinating clump. Watch these areas closely for signs of potential silk clipping as hungry CRW populations build up in them ? high numbers of CRW beetles could interfere with pollination and grain fill. 

Since these areas can be at higher risk for egg laying, make a note of their location(s). Record any scouting information. Should egg laying be high enough in those islands, it is a good bet that they would be at higher risk for lodging from CRW larval feeding next year should corn be replanted into the same field. Better yet, if cropping schedules allow, this field may be a good candidate for rotation next year.

NOTE: The sequential sampling method for sampling CRW assumes the field is uniform in physiological development. This sampling procedure is dependent on an even distribution of corn rootworm beetles across the field.  Fields with uneven development from uneven germination or water stress should not be sampled using this sequential sampling procedure since the beetles will be clumped on pollinating plants.

If sampling for CRW in fields with uneven growth development follow the method recommended in the Cornell Field Crops Guide.  CRW counts are taken from 55 corn plants sampled at random. The threshold is an average of 1 western corn rootworm beetle / plant  (or 2 northern CRW beetles / plant). When determining fields at risk recall that the Western corn rootworm beetles count as one and northern CRW beetles count as0.5. For more information see the Cornell Guide for Integrated Field Crop Management field corn insect ( CRW) management ( (see field corn insect management section)

Partial Alfalfa Field Harvest Increases PLH risks

Keith Waldron

return to top

Are PLH in your alfalfa fields? If so, avoid partial field harvests to best manage PLH populations. Clean harvest of whole alfalfa fields is optimal, however our recent stretch of rainy weather has surely messed up more than one harvest schedule sometimes stopping a hay harvest in mid-stride. These partially harvested fields can set the stage for future PLH problems.  In situations where edges or portions of alfalfa fields have been harvested but other areas of the field are left intact watch closely for PLH populations and potential injury.

Adult PLH in the standing portion of the field can easily relocate to the shorter portion of the field and attack the vulnerable regrowth. The shorter alfalfa has a lower threshold for PLH than taller alfalfa so is at much higher risk for injury.

Harvesting remaining portions of the field assoon as is practical is recommended to minimize PLH population buildup andtheir easy movement to adjacent portions of the field.

Soybean Rust Update

Gary Bergstrom
Plant Pathology, Cornell University

return to top

Scouting has begun in sentinel plots in NYS in Cayuga, Jefferson, Seneca, Washington and Wayne counties. Last week low levels of bacterial blight, bacterial pustule and Septoria brown spot were detected in samples submitted from the NYS sentinel network. Nationally, on July 28th,soybean rust was reported on soybean in a sentinel plot in Assumption Parish, Louisiana. Risk of spore transport to our region is low at this time. In 2009, soybean rust has been reported in the U.S. in 32 counties in five states (Alabama, Florida, Georgia, Louisiana and Texas). Updated July 29, 2009

NY State Soybean Rust Hotline:607-255-7850

NYS Soybean Rust Website

USDA Soybean Rust Website

Clipboard Checklist

Keith Waldron

return to top

* Emergency contactin ormation ("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 any patches of herbicide resistant weeds, weed escapes
* Storage areas cleaned and ready to accept hay, wheat harvest
* Monitor fields for plant vigor, growth stage, mid season pest issues (European corn borer, armyworm, foliar diseases, nutritional deficiencies)
* Check no-till fields/fields with high residue or weeds for slug/snail damage
* Monitor for weeds, note presence of "who", "how many" and "where"
* Monitor tasseling corn fields for presence of corn rootworm beetles.

Small Grains:
* Monitor winter grains for crop stage (heading, grain fill), insect problems (cereal leaf beetle, armyworm) and foliar / head diseases
* Evaluate crop for plant vigor, lodging, maturity / time till harvest
* Grain bins ready to accept upcoming harvest?

Alfalfa & Hay:
* Monitor alfalfa seedings for weeds, insects & diseases.
* Check regrowth of established alfalfa stands for potato leafhopper, weed and disease problems.
* Storage areas cleaned and ready to accept incoming harvest
* Evaluate stand growth, development and condition
* Monitor fields for soybean aphid, foliar diseases, white mold, naturalenemies, weed escapes

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 water sources, drainage, roof gutters for leaks and potential overspill
* Continue fly monitoring: install "3X5" index card fly speck monitoring cards through out barn
* Install/refresh/replenish as needed: fly tapes, insecticide baits, natural enemies (parasitoids
Dairy Livestock Pasture Fly Management:
* Monitor animals for presence of pasture fly pests. Treatment guidelines: Horn flies (50 per dairy animal side, 100 per side for beef cattle), face flies(10 per animal face), stable flies (10 per 4 legs). See:
* Consider installing biting fly traps to reduce horse, deer and stable fly populations.

* Check storage areas (bunk silos, etc.) for readiness to accept upcoming wheat harvest
* Clean in and outside of storage bins and grain handling equipment
* Keep areas around storage bins and silos clean and mowed
* Check areas around storage bins and silos for vertebrate tunneling
* Check temperature of recently baled hay in hay mow

* Note any repairs needed for recently used equipment: tractors, tillage implements, planters, sprayers, etc. as they are cleaned and serviced.
* Service hay harvesting equipment as needed.
* Calibrate manure spreaders - maintain records on amount spread per field

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.

Mark Your Calendars

return to top

Aug. 10-14, 2009 -- Soil Health Training Workshop, Ithaca, NY

Contact Information

return to top

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

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