Washington State University Cooperative Extension

Areawide IPM Update

The Newsletter of Pheromone-based Orchard Pest Management

Vol. 2, No. 5 -- April 15, 1997

Cooperating agencies: Washington State University, Oregon State University, University of California, U.S. Department of Agriculture, and Chelan County.

Cooperative Extension programs and employment are available to all without discrimination.

Apple Maggot

Starting Right With Mating Disruption: Installing Dispensers Correctly

If you have decided to use mating disruption in your codling moth control program this year, then you must pay attention to these key points when installing the pheromone dispensers.

Apply at the right time: Dispensers must be in place in the orchard before codling moth flight occurs. The moths mate soon after the first male flight, which generally occurs close to full bloom of Red Delicious apples. In any codling moth management program it is crucial to control the first generation as well as possible. Applying dispensers late increases the risk that successful mating, egg lay and fruit infestation will occur, and create the need for further controls later in the summer aimed at the second generation. It is far better to apply the dispensers two weeks before flight than even one week after. The dispensers available today are designed to fully cover both codling moth generations when label directions are followed. Research in Washington and Europe has found that the Isomate-C+ dispenser continues to release codlemone even in the spring and early summer of the year following the initial application.

Place high in the tree: Dispensers should be placed within the top two feet of the canopy, at or above the level of any fruit. Codling moth activity and mating are concentrated in the top third of the orchard canopy, and the pheromone is heavier than air, tending to sink towards the orchard floor as it is released from the dispensers. It is important to supervise the application of the dispensers so that this height is maintained, particularly later in the day when arms get heavier and trees seem to get taller!

Attach securely: Attach the dispensers to shoots or spurs coming off of major limbs. Avoid applying directly around the main branches, because of the risk of later girdling them. Apply to sturdy limbs that won't bend too low with the weight of fruit later in the season.

Apply uniformly: For successful mating disruption, there should be few holes in the pheromone "cloud" in the orchard. Pheromone dispensers must be placed uniformly throughout the treated orchard. If a few trees are missing, place the extra dispensers in the surrounding trees. Likewise, if there are scattered small interplants in the block, place the dispensers that these trees would have received in the surrounding taller trees, so that dispensers are not placed just six feet or less from the ground. Charts are available with guidelines for dispenser spacing based upon many different tree spacings. A particularly complete set was developed by Kelly Denton, coordinator of the Howard Flat CAMP site. The chart is available from Kelly or by contacting me.

Application method: Most people now use extendible poles or lengths of PVC pipe to place dispensers high in the trees. With experience, crews have applied 400 Isomate dispensers per acre in no more than two man-hours per acre. Even less time per application is needed for the Checkmate and Disrupt dispensers, applied twice per season at 120-160 and 200 dispensers per acre, respectively. Ladders can also be used for dispenser application but this method takes considerably more time and increases the accident risk.

Dispensers for codling moth mating disruption

There are three principal pheromone dispensers registered for codling moth mating disruption, each with distinctive characteristics. The codlemone release rates listed are approximate. Actual rates vary with several factors in the orchard environment, particularly temperature and wind speed.

Checkmate CM is a flat rectangle, ca 2.25" by 4.5," containing a minimum of 180 mg of codlemone [(E,E)-8,10-dodecadien-1-ol]. It is designed to release from 2.0 to 3.0 mg of pheromone per day. Recommended application rate for pome fruits is from 120 to 160 dispensers per acre, with the higher rate being used more commonly on orchard borders, the tops of slopes and in higher codling moth pressure areas. Checkmate CM uses a dual membrane system to extend the pheromone release over an expected period of up to 70 days. Two applications per season are needed to cover both codling moth generations. There are two types of Checkmate CM dispensers: the Cool Season (CS), intended for the first (spring) application, that contains a minimum of 180 mg of codlemone, and the Warm Season (WS), intended for the second (summer) application and containing a minimum of 270 mg of codlemone. Use of these two types is intended to provide a more uniform release of pheromone throughout the season. Checkmate CM is sold in buckets containing 600 dispensers, enough to treat up to five acres, and comes with the application clips attached. This dispenser, first registered in Washington State in 1994, is a product of Consep, Inc., of Bend, Oregon.

Disrupt CM is an orange vinyl laminate measuring 2" by 2" which comes attached to a plastic clip, ready for hanging in the orchard. This dispenser contains 160 mg of codlemone and is designed to release an average of close to 1.0 mg per day. Two applications per season of Disrupt CM are recommended, at an application rate of 200 dispensers per acre. The recommended interval between applications is 75 to 90 days. Disrupt CM is sold in packages containing 100, 200 or 1,000 dispensers. This product was first registered in 1996 by Hercon Environmental Corporation of Emigsville, Pennsylvania.

Isomate-C+ is a red polyethylene tube, 6" long, containing a reservoir with at least 120 mg of codlemone. In contrast to the other two dispensers, it also contains two alcohols in the formulation found to be biologically active components of the codling moth pheromone. A wire attached alongside the tube allows the dispenser to be tied onto clips for attachment or twisted directly onto small branches. A device for this direct attachment, called "The Hoop," has been developed that is easy and inexpensive to manufacture. (Contact the dispenser manufacturer for instructions.) The permeable plastic of the Isomate-C+ dispenser is designed to release an average of 0.6 mg of codlemone per day for the season, under Washington conditions. One application per season, at 400 dispensers per acre, is recommended. This dispenser was first registered in 1991, and is sold in packages of 400. It is manufactured by Pacific Biocontrol Corporation of Vancouver, WA.

Camp "sights" on the WWW

Aerial photographs and maps of the first five CAMP sites are now available on-line. Craig Ferguson of the USDA-ARS Yakima Agricultural Research Lab has created a site where they may be viewed. These sites may include black & white and color aerial photos, 3D perspective images, infrared images and maps showing block ownership and tree fruit varieties. They may be found at: http://pwa.ars.usda.gov/yarl/areawide/oroville.html, /randalli.html, /howardf.html, /parker.html, and /medford.html For more information on the areawide program and links to related sites, check out: http://pwa.ars.usda.gov/yarl/areawide/areawide.html

Camp site notes - April 1997

Randall Island - The RIP has entered its fifth season of areawide codling moth management using mating disruption. Acreage at this site in the Sacramento River Delta region remains at 760 acres, with the same participating growers. In years past they have made two applications of Isomate-C+, to counter the extremely high codling moth populations of this hot location. To create a more affordable program, they are recommending one application of Isomate-C+ applied during the first generation but after the flight has begun, supplemented with an insecticide spray at 600-700D after biofix. Codling moth damage in the RIP has always been less than 0.5% whenever there was at least one organophosphate in the control program.

Ukiah - This site in Mendocino County, California, will be part of the CAMP for the first time in 1997, but is entering its second year of using mating disruption on an areawide basis. Dr. Lucia Varela, with UC Cooperative Extension, is serving as site coordinator. Acreage in the project this year will be 550 acres, up from 400 last year, with nine growers participating. Pears make up all of the acreage, mostly Bartlett, with lesser amounts of other cultivars. They will use two applications of Isomate-C+ this year, the first at 400 dispensers per acre just prior to the first flight (late March), and a second application of 200 per acre applied 900-1000D later. Supplemental sprays will be applied as indicated by pheromone trap catch.

Carpenter Hill (Medford) - This site has increased in size to 500 acres, up from 400 acres in 1996 and 300 in 1995. The addition of these new, contiguous acres brings total pear acreage to 440 acres, together with 60 acres of apples. One application of Isomate-C+ at 400 per acre will be used again this year. The spray program will continue as in the past two years, with the base program on pears including two pre-bloom oils, three foliar oils (applied at 200D, 400D and 600D) and a late season azinphosmethyl application at 1250D. Bloom timing and the amount of bloom appear close to normal this spring.

West Parker Heights - At this site, one of the original five CAMP sites, acreage and grower participation remain essentially the same as last year, with 469 acres and 7 growers. Some growers are considering reducing MD dispenser application rates in selected blocks. Acreage using the dual leafroller/CM pheromone dispenser, available for research only from Pacific Biocontrol, will be increased from 20 to 40 acres. Blocks which sustained the most leafroller damage in 1996 (these were typically older, large goldens) were pruned with better spray coverage in mind.

West Wapato - This new CAMP site is located several miles west of Wapato, WA, in the lower Yakima Valley. Some 20 growers are included in this site of over 800 acres. Almost all of the acreage is in apples, with only about 30 acres of pears. The area is relatively flat, favorable for mating disruption success, but is challenged by the open areas within the site from roads, a canal, residences, unplanted fields and non-participating orchard blocks. Codling moth pressure has been moderate, with generally three to four covers being applied per season. Brad Higbee, an entomologist with USDA-ARS lab near Wapato, is serving as the site coordinator here, in addition to serving in the same role with the West Parker Heights site.

Howard Flat - Close to 600 acres have been added to this site near Chelan, WA, bringing the total acreage to nearly 1700 acres, and the number of growers to 57. The additional acreage extends from the eastern edge of the City of Chelan towards the east and northeast, and is much more hilly than the original area. Codling moth pressure is high for many of the new blocks, with five or more covers being applied and areas with significant damage. The original 1100 acres on Howard Flat itself enters its third year of extensive mating disruption use this year. With very low damage levels last year from codling moth, and most growers only applying one cover spray, many growers this year will be reducing dispenser rates in areas, not applying a cover spray, or both. The local chapter of the FFA has constructed the site's pheromone traps (ca. 1000) and made the hoop applicators for the growers' application of Isomate-C+. Kelly Denton will continue to coordinate this expanded site, and the Howard Flat Management Board has hired a full time scout to assist him.

Manson - This new site on the north shore of Lake Chelan will be approximately 1410 acres, involving some 70 growers. Codling moth pressure for many growers in this area has gone up greatly over the past five to ten years, with increases in both sprays and damage. Mating disruption is complicated in this area by the hilly topography of the site and the many small and irregularly shaped blocks. However, interest in mating disruption in this area is high, encouraged by many local consultants and the positive experiences of growers in the area, who have found that including mating disruption in their control program has often reduced damage and reduced expense. A management board of growers and consultants from the site has been created, and two people have been hired to do trap monitoring and data entry. Isomate-C+ will be used here, with many growers opting to use it at reduced rates to supplement a reduced cover spray program.

Brewster - This site, known locally as BAM (Brewster Areawide Management), is new in 1997. It will exceed 2100 acres, extending north and east of the City of Brewster, and making it the largest of the ten CAMP sites. At least 44 growers are involved. Codling moth pressure for most blocks has been low to moderate (one to four covers). The management board is recommending a minimum rate of 200 Isomate-C+ per acre, supplemented with sprays as needed. Leafrollers, particularly obliquebanded, are a greater problem for many growers, and many joined BAM to take part in a coordinated and concerted leafroller management program. All growers are being encouraged to apply a pre-bloom Lorsban(r), followed with two Bt applications in warm weather during the pink to post-bloom period. Due to the site's extensive size and limited budget, trapping will be done at a lower average density than other CAMP sites. Codling moth traps will average one per five acres, with placement biased towards areas with a higher codling moth history or risk. Another unique feature of this site is that the growers have created a Limited Liability Corporation (LLC), a business structure for project and financial management that also protects the management board members from any personal liability.

Progressive Flat - The fifth new site for 1997, Progressive Flat is located directly above the City of Okanogan. Twenty five growers are involved and 600 acres (530 apples and 70 pears) will be treated. Codling moth pressure has been low to moderate, and leafrollers have been few and far between. The management board is recommending that all growers use Isomate-C+, and is supplying the hoop applicator to the growers. All growers are expected to apply at least one cover in the first generation. Ron Moon, former Okanogan County Pest Board fieldman and a grower within the site, is serving as the site coordinator.

Lake Osoyoos - This site has also grown, with the addition in 1997 of eight growers and close to 300 acres on the east side of Lake Osoyoos. The original 393 acres will continue to release sterile codling moths from the Sterile Insect Release facility in nearby Osoyoos, British Columbia. This year the releases will begin with the start of the first generation in May, instead of waiting until the second generation as was done in the past two seasons. Some growers will use reduced rates of Isomate-C+ dispensers in their third year of mating disruption, particularly in low pressure areas and block interiors, and more will probably apply no covers to some blocks or portions of blocks.

Ted Alway, Editor
Phone: (509) 664-5540
Fax: (509) 664-5561
e-mail: alway@coopext.cahe.wsu.edu

Partial Funding provided by: Washington State Tree Fruit Research Commission, U.S. Department of Agriculture-Agricultural Research Service.

WSU Cooperative Extension, Chelan County
400 Washington St.
Wenatchee, WA 98801

Wenatchee WA, 4 April 1997