Weekly Field Crops Pest Report 2010
May 21, 2010 Volume 9 Number 5
View from the Field
Western NY reports alfalfa fields over threshold for alfalfa weevil. Some of these fields have suffered yield losses. Keith Waldron scouted alfalfa fields at the Cornell Experiment Station in Geneva as found 2nd to 4th instar larvae. The 4th instar of alfalfa weevil will eat 80% of all the forage it will eat in its life-time. As seen in the following photo if given the chance alfalfa weevil can significantly damage alfalfa yields.
Figure 1: Alfalfa Weevil Damage
I am seeing 1st and 2nd instar larvae in alfalfa at SUNY Cobleskill and the Cornell Farm in Valatie. The alfalfa was 18 to 22 inches tall this week. Wheat rust was reported on wheat in western NY. It is believed that this rust might have overwintered in NY. There are many reports of corn starting to emerge in fields. Corn and soybeans are still being planted statewide.
Keep on the lookout:
While states adjacent to NY have reported black cutworm, armyworm and cereal leaf beetle activity, we have not heard of any significant issues with these insects at this time.
Last week most of the state was colder than normal, but temperatures ranged from less than 3 degrees below normal to 3 degrees above normal. Precipitation ranged from less than .01” at the northernmost point of the state up to two inches in southeast NY. A majority of the state was in the half to one inch range. Jefferson county which has been dry only got between .01 and half an inch.
The base 50 Growing Degree Days ranged from less than 25 to 50, the same as the previous week. Most of the state is 3-7 days ahead of last year. But large areas in Allegany, Oswego counties and the Mohawk Valley and Northern Plateau range 3 days ahead and behind last year. The entire state is ahead of normal; ranging from 3 to 14 days ahead.
We will see above normal temperatures for the next week. Today and tomorrow will have highs in the 70’s and around 80 and no precipitation likely. Tonight’s lows will be in the mid 40’s to mid 50’s. Friday night will range in the 50’s. Saturday a low pressure system over the great lakes will bring a chance of showers for western NY. Highs will be in the 70’s with lows in the mid 50’s to near 60. Sunday the showers will move across the state with highs continuing in the 70’s. Overnight lows will be in the mid to upper 50’s. Monday high pressure will take control and highs will be in the upper 70’s to low 80’s. Lows will be in the mid to upper 50’s. Tuesday will have sunny skies and temperatures reaching the low to mid 80’s with lows in the mid to upper 50’s. Wednesday ‘s temperatures will be in the low 80’s and the upper 50’s to low 60’s overnight.
The five day precipitation totals will be a tenth to half an inch. The 8-14 day outlook is showing above normal temperatures for the western half of the state and below normal precipitation for the whole state. Jefferson and St. Lawrence counties are still abnormally dry.
Alfalfa Weevil and Parasitoids
Alfalfa weevils have many natural enemies. One group of these are tiny beneficial wasps called parasitoids. Some parasitoid species attack weevils in their egg stage, other types attack larvae, and still other types attack adults. A common weevil parasite (Bathyplectes spp) lays its eggs in late instar larvae just before they pupate. The parasitoid egg hatches and the young wasp feeds on the developing pupa effectively killing the weevil before it completes its development. If you find a weevil cocoon and instead of a healthy green to brown weevil pupa you find a small dark brown egg-shaped structure with a white band around the middle and about 1/8 inch long you have found the cocoon of a Bathyplectes parasitoid. The natural predator has devoured the alfalfa weevil pupa. Biological control in action!
Figure 2: Bathyplectes anurus cocoon and an alfalfa weevil larva
Lady Beetle of the Week!
I found a few seven-spotted lady beetles (Coccinella septempunctata) in alfalfa this week. The seven-spotted lady beetle introduced from Europe in the 1970s, is 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.
Figure 3: Seven-Spotted Lady Beetle, Coccinella septempunctata
I have pooled my lady beetle data for this season. In the following graph depicts data from 8 fields at SUNY Cobleskill and the Cornell Farm in Valatie. Each field received 200 sweeps with a 15 inch sweep-net and beetles were counted. I find it interesting the changes in species from week to week. As it gets warmer I think we should see more beetles including different species.
Figure 4: Number of lady beetles in 8 fields at 200 sweeps/field
Jump Start Barn Fly Management
It is early in the season and so far we are ahead of the curve, but as temperatures increase so can house and stable fly populations. Confined livestock facilities can contain perfect habitats for house and stable fly populations to develop. The good news is 90% or so of the potential fly problem these fly issues can be controlled by eliminating fly breeding habitat. It is never too early to begin thinking about fly management A little effort 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. Locations that remain relatively undisturbed and offer protection from foot and hoof traffic are favorable fly habitats. Frequent clean out of these 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.
Reducing the number of adult (breeding) flies helps minimize the potential for fly population buildup. With sound sanitation as the foundation for fly management, additional tactics can be brought to bear such as insecticide bait stations and sticky tapes to reduce the breeding population of flies.
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.
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 is 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. Now would be a good time to begin releasing the fly predator wasps in barns and calf housing areas. These 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. For NY dairy operations, we recommend the parasitoids Muscidifurax raptor or Muscidifurax raptorellus alone or in combination. Our experience at Cornell has shown a need to obtain climatically adapted strains. One local source of parasitoids is IPM Laboratories in Locke NY. (315.497.2063).
We are still in the relatively early stage in our understanding of how to use biocontrol to full advantage in fly management programs and are very interested in hearing about producer experiences on how well fly predators are working for them.
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.
IPM Guide for Organic Dairies Now Available
The IPM Guide for Organic Dairies provides an outline of practices for the management of external arthropod pests such as flies, lice, mites and grubs on organic dairy farms. Left uncontrolled, these pests negatively impact animal health and production.
While organic production has recently increased, information about how to farm organically is still in need of considerably more research. This guide compiles the most currently available information on dairy arthropod pests, but acknowledges that effective means of organic control are insufficient for some of these pests. As new information becomes available, it will be incorporated into future revisions of this guide. While critical to organic dairy production, this guide does not include information on nutrition, feed stocks, or internal parasites of dairy cattle.
This guide is broken into sections beginning with a brief overview of the certification process. Sections on fly management are broken down into those found in and around confined areas and shelters, as well as those found when cattle are on pasture. Each section re- views the biology and importance of each pest along with monitoring and assessment recommendations followed by pest management techniques. A separate section addresses management of lice and mange. Specifics on biological control, trapping, and pesticide options conclude the guide.
This guide uses the term organic integrated pest management (IPM), which utilizes a series of decision-making steps to manage pests. To ensure success, dairy producers need to properly identify pests, understand pest biology, monitor pest populations, assess the need for control, and then reduce pest populations to accept- able levels through cultural, biological, mechanical, and chemical management techniques.
Growing Degree Days for NYS
Growing degree Days for peak (50%) Occurrence of Alfalfa Weevil growth stage:
(Note: for alfalfa weevil predictions use Base Temp of 48F)
CURRENT Accumulated Growing degree days (48F Base)
March 1 - May 19, 2010
*Indicates missing data
Alfalfa and Grass Hay:
Cattle on Pasture:
*Monitor animals for presence of face flies, horn flies and stable flies. Action guidelines: face flies (average 10 per animal face), horn flies (average 50 / dairy, 200 / beef cattle per animal side), stable flies average 10 per animal (all four legs)
* Check paddocks for forage quality / quantity, rotate as appropriate
Dairy Cattle Barn Fly Management:
PESTICIDE EMERGENCY NUMBERS
Poison Control Centers
Mark Your Calendars
June 3 -- Small Grains Management Field Day, Musgrave Research Farm, 1256 Poplar Ridge Rd., Aurora, NY . Free registration at 9:00am. Program runs from 10:00am-12:00 noon. Dec and CCA credits have been applied for. For more information contact Larissa Smith at 607-255-2177 or firstname.lastname@example.org
July 14-- Weed Science Field Day, Thompson Research Farm, Freeville, NY (morning program)
July 14-- NYSABA Summer BBQ, Musgrave Research Farm, 1256 Poplar Ridge Rd., Aurora, NY (12:00 noon)
July 14-- Weed Science Field Day, Musgrave Research Farm, 1256 Poplar Ridge Rd., Aurora, NY (1:30pm 5:00pm)
July 22-- Aurora Farm Field Day, Musgrave Research Farm, 1256 Poplar Ridge Rd., Aurora, NY (10:00am-3:00pm)
Keith Waldron: NYS Livestock and Field Crops IPM Coordinator
Ken Wise: Eastern NYS IPM Area Educator: Field Crops and Livestock