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Weekly Field Crops Pest Report 2012

July 26, 2012, Volume 11 Number 15

  1. View from the Field
  2. Weather Outlook
  3. Western Bean Cutworm Update
  4. Clipboard Checklist
  5. Contact Information

View from the Field

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Potato leafhopper (PLH) populations are still high statewide. Many growers are spraying their fields. If the alfalfa is short and your field is over threshold, you should control PLH to avoid yield and quality losses. Short alfalfa is at higher risk for damage than taller plants.

With the hot dry weather it is bound to happen!!! Two spotted spider mites are causing problems in soybeans. Mites really proliferate and thrive when its hot and very dry. They tend to build up along field margins as they move in from grassy field edges, ditchbanks, etc. Infestations tend to move into the field in a “V” shaped pattern, with the broader infestation along the field edge narrowing as it moves into the field. When its dry, naturally occurring fungus diseases that normally help control mites can’t develop.

spider mite damage
Spider mite damage to soybeans.

Red headed flea beetles are reported in soybeans this week. While they feed on leaves and can cause some defoliation these insects do not transmit virus diseases to soybeans. This flea beetle, about 1/16 inch long, is shiny black with a reddish head. To assess damage, look at the percentage of defoliation on the leaves. Midwestern states suggest that 15 to 25% defoliation by all leaf feeding insects during pod fill is an economic threshold for control. We rarely get to that point in soybeans in New York.

Both western and northern corn rootworm adults have been reported. Not only is western corn rootworm more common, but their larvae do twice the damage northern corn rootworm do. Meanwhile, drought stress means many cornfields are unevenly pollinated this year. This makes it tricky to assess damage. Many adults are feeding on silks—clipping them and sometimes preventing pollination. If the silks haven’t yet been pollinated and beetles clip them to less than a ½ inch long, a control could be warranted: such has been the case in western NY. There are reports of goose-necking in corn. The corn rootworm larvae devour so much of the roots, the stalks fall over. Once fallen, the corn curves at the base as it begins growing straight again

Goose-necking in corn

True armyworms are reported again in some grass hayfields. Their size ranges from ½ to 1 inch. Smaller larvae (1/4 to ½ inch) can be detected using a sweep net in early morning, late afternoon or evening. As larvae get larger they go to the lower canopy or soil surface during the heat of day. If you’re out with your sweep net during the day, also check for larger larvae near the soil surface.

Western bean cutworm moth captures continue. Several scouts report catching high numbers. Learn more from the “Western Bean Cutworm Update” below.

I have been doing a lot of livestock pasture-fly meetings this summer, and face flies are really bugging cattle. They not only irritate cattle (with downstream effects on weight gain, milk production, etc.), but they can vector pink eye. Producers say pink eye has been on the increase the past few years. Also, I’m starting to see horn flies on cattle. The funny thing is that stable fly numbers this summer seem low so far.

Weather Outlook

July 26, 2012
Jessica Rennells, Northeast Region Climate Center, Cornell University

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Last week temperatures ranged from 0 to 3 degrees above normal for most of the state; some areas ranged 0-3 below normal. Rainfall amounts ranged widely from a trace up to 2 inches. The Base 50 growing degree-days ranged from 100 in the northern areas to 175.

Severe weather & rain!

Warm, humid conditions have returned. Thursday’s cold front later brought more showers and thunderstorms and the possibility for severe weather. By now it should have moved out, but there is still a chance for locally heavy rainfall. Unsettled weather and scattered showers will persist. Highs will be throughout the 80s; lows will be in the 60s.
Saturday will be mostly cloudy with highs in the upper 70s and low 80s. Another disturbance will bring the chance for scattered showers and thunderstorms. Overnight temperatures will be in the low to mid 60s.

Sunday will be mostly sunny with temperatures in the low to mid 80s; a slight chance for a shower. Lows will be in the upper 50s to mid 60s.

Monday will be sunny with highs in the 80s. Lows will be in the low to mid 60s.

Tuesday will be in the 80s with mostly sunny skies, but a chance for showers. Overnight temperatures will be in the 60s.

Wednesday temperatures will be in the 80s with possible scattered showers and thunderstorms. Lows will be in the mid to upper 60s.

The five-day precipitation amounts will range from ¼ inch in the northernmost areas of the state, up to inches. The 8-14 day out look is showing above normal temperatures and normal precipitation Abnormally dry and moderate drought conditions remain the same, though the upcoming rain should provide some relief.

National Weather Service Climate Prediction Service Maps of 8-14 day outlooks

National Weather Service Eastern Region Headquarters watch/warnings map

NRCC Drought Page which features the US Drought Monitor map (updated every Thursday)

Western Bean Cutworm Update

Keith Waldron

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Western Bean Cutworm traps continue to attract more moths this week. A total of 955 WBC moths were caught in the 57 traps reporting this week, up from 467 WBC moths in 64 traps caught last week. Trap catches ranged from 0 to 158. Accumulated WBC moths per trap currently average 27.3 moths per trap. Overall the majority of our NY trap catch numbers are still relatively low and do not indicate any cause for concern. High counts were recorded in north and western counties: Lewis (158), St. Lawrence (123), Jefferson (74) and Wyoming (91). The large number and the condition of the moths in these traps suggests many of these moths travelled some distance and were migrants, most likely from Ontario. (Moths recently captured in NY have typically been in relatively good condition, indicating local sources).

Average number of western bean cutworm moths captured per trap.

western bean cutworm chart

Corn fields adjacent to trap locations in St. Lawrence, Lewis and Jefferson counties were checked this week for egg masses, none were found. Suspected WBC egg masses were collected in Franklin county this week.
In 2010 and 2011, NY WBC numbers peaked the week of August 2. The NY WBC trapping program will continue through August. See last week’s WPR for scouting information and pictures of WBC egg masses.

WBC monitoring information is available at this Weekly Pest Report article.

WPR also available in the field "blog" section. 

Cornell Sweet Corn Monitoring Network
Penn State Pest Watch (Includes WBC data from NY, New England and other states)
Ontario WBC Trap Network

Western Bean Cutworm - Corn scouting videos:

Stay tuned for more information.

Clipboard Checklist

Keith Waldron

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* 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 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, vegetative stage pest issues (corn rootworm larvae, European corn borer, armyworm, foliar diseases, nutritional deficiencies)
* Monitor for weeds, note presence of "who", "how many" and "where"

Small Grains:
* Evaluate crop for maturity, lodging, time till harvest
* Grain bins ready to accept upcoming harvest?

Alfalfa & Hay:
* Monitor alfalfa seedings for weeds, insects & diseases.
* Check re-growth of established alfalfa stands for potato leafhopper, weed and disease problems.
* Storage areas cleaned and ready to accept incoming harvest
* Monitor grass hay fields for armyworm

* Evaluate stand growth, development and condition
* Monitor fields for soybean aphid, foliar diseases, white mold, natural enemies, weed escapes, spider mites
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 throughout 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.

Contact Information

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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