Washington State University Cooperative Extension

Areawide IPM Update

The Newsletter of Pheromone-based Orchard Pest Management

Vol. 3, No. 6   June 1, 1998

Inside this issue:

Web links:

...Ted Alway's Areawide IPM page

...USDA Yakima Areawide IPM page (with CAMP site descriptions)

...WSU-TFREC Entomology home page

...Index to Areawide IPM Update newsletters

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.


Codling Moth Mating Disruption Use in Washington State

M ating disruption of codling moth is being used on an increasing number of acres in Washington State. An estimated 37,000 to 40,000 acres are being treated in 1998, up from close to 27,000 acres last year. Total acres treated with codling moth mating disruption in western North America should approach 60,000 acres this year. I surveyed Washington growers who used this practice in 1997 to learn the particulars of their mating disruption use and to learn of their plans for future years.

153 growers responded to the survey, representing nearly 11,500 acres of mating disruption (MD) in 1997. All apple and pear growing districts in Central Washington were represented, with nearly 65% of the treated acreage coming from North Central Washington (Chelan, Douglas and Okanogan Counties), 20% from the Yakima Valley and 15% from the Columbia Basin. The MD acreage was mostly in apples, but 755 acres of pears, farmed by 44 growers, were also included.

First time users of MD accounted for over 40% of the respondents, reflected in the fact that this survey group had no more than 7000 acres in MD in 1996. Growers with two years of experience represented 12% of the group, three year users 18%, four to five years 17%, and six or more years 10%. These same growers planned to expand MD acres further in 1998 by about 25%. Of the total surveyed group, 37% planned to increase treated acres, 56% planned to stay the same (most of this group having already treated their entire acreage) and 7% planned to reduce the acres treated; those reducing acres did so either because they figured MD was not cost effective for them or they had reduced their bearing acreage.

Dispenser type: The Isomate C+ pheromone dispenser was by far the most popular, being used by 92% of the growers surveyed. The Checkmate CM dispenser was used by 5% of the growers, and 3% used both types in their orchards.

Isomate C+ is increasingly being used at less then the full rate of 400 dispensers/acre. 73% used this dispenser at reduced rates on all or part of their acreage, up from 45% in last year's survey. Many treated just borders or known hot spots with 400/acre. Among first year users, 85% began MD use with Isomate C+ rates of close to 200/acre. In 1998, 70% of the growers surveyed plan to use Isomate C+ rates of about 200/acre, 15% at rates close to 300/acre and 15% at the full rate of 400/acre.

Checkmate CM was used in 1997 by 12 growers on 6% of the MD acreage in the survey, down from 18% of the acres in the previous survey. Only 7 growers planned to continue using this dispenser in 1998.

Supplemental sprays: MD was supplemented with insecticides by 86% of those responding, even if only to limited border areas, and 14% used MD alone for codling moth control. 23% of pear producers used no supplemental sprays, versus 12% of apple growers. 9% of the surveyed growers applied less than one full cover spray, 39% applied one cover, 30% applied one to two covers, and 8% applied more than two sprays for codling moth control in addition to using MD. Among first year MD users, 95% applied at least a partial cover spray; this percentage was reduced to 83% in the second year of MD and 76% among those using MD three or more years.

Guthion was by far the most common material used as a supplemental spray, used by 90% of the growers. Other materials used, to a far lesser degree, included Imidan , Penncap-M , ryania and foliar oils.

Comments: When asked if they were satisfied with their use of MD, 92% of growers responded "yes", 3% responded "no", and 5% were undecided. The most common reasons that growers cited for including MD in their pest management programs were that it resulted in less or no codling moth damage, less codling moth control costs or both. Many stated that by using MD together with a reduced cover spray program they were able to clean up previously high pressure/high codling moth damage orchards. Many growers noted increased numbers of beneficial insects (parasites and predators) in their orchards when MD was used and cover sprays were reduced but only a few indicated that they actually observed lower secondary pest populations as a result. Pear psylla, and to a lesser extent aphids and leafminers, were said to be better controlled biologically in these cases. A number of growers said they were spurred to include MD in their control programs by the potential loss or restriction of use of many pesticides as a result of the Food Quality Protection Act.

Even growers who were satisfied with MD complained about its cost, which was the single greatest concern. Several growers in low codling moth pressure areas, where but one or two sprays annually provided good control, were reducing or even stopping their use of MD the following year as they felt they would have more cost-effective pest control without it. Secondary pests (pests other then codling moth) were a concern for many in this survey. Some pest problems (leafrollers and, for some, webworms) frequently became worse when cover sprays of broad-spectrum insecticides were reduced or eliminated; other secondary pests (particularly stink bugs, campylomma and cutworms) caused problems apparently unrelated to MD use but requiring insecticide sprays nonetheless.

Based on this survey, and other comments from growers and consultants in the state, we can expect the use of codling moth MD to continue to grow for at least the next few seasons. The increase in MD acreage in Washington has averaged nearly 40% per year for the past four years. More growers will come to echo the statement of one respondent who stated, "After seeing the results, I'm a believer".


Notes From the New CAMP Sites

S even new sites received funding from the USDA-ARS in 1998, and are using codling moth mating disruption on an areawide basis for the first time.

South Shore (Lake Chelan) - Tom Fruit is coordinating this 600 acre site, in addition to the over 1600 acres he works with in the Howard Flat CAMP site. Casey Mackey is assisting him. Twelve growers are involved. The site rises up steeply from the shores of Lake Chelan, with some blocks steep enough to almost require a rope belay! Codling moth pressure historically has been low to moderate, and there has been no use of mating disruption here previously. Moth catch totals after the first several weeks are moderate, with a few hot spots catching up to 25 moths/trap/week. Most growers will apply two covers for the first generation, with some areas with low counts to receive only a single spray. Isomate C+ dispensers are being used at about 200 per acre, often with a higher rate of 400/acre along the top edges of the orchards. As in most Washington apple orchards, bloom was very heavy and a large crop is anticipated.

East Wenatchee - Close to 600 acres are involved in this site by the airport near East Wenatchee, WA. Twelve growers are participating, and coordination is provided by Scott Driscoll of Stemilt Management. There were nearly 350 acres using codling moth mating disruption in this area in 1997. Initial codling moth catch has been low, with less than 30% of the traps with any catch in the first several weeks. Leafrollers have been a problem for some growers in this area; surveys so far have turned up few larvae, and pheromone traps were installed late in May. Some of the acreage will use the Isomate CM/LR ("dual") dispenser this year, installing them when the first leafroller flight begins.

Babcock Ridge - This site lies several miles west of Quincy, WA, and involves 720 acres and 8 growers. Coordination is provided by Nick Stephens, with assistance from Gabriel Flores. Codling moth pressure has been low, and initial counts this spring confirm this. The growers are using 200 Isomate C+ per acre. Most growers supplemented mating disruption with one cover spray applied at a delayed first cover timing (360 degree-days after biofix), with a few sites with higher trap catch opting for two covers for the first generation. Some blocks with no codling moth catch treated their borders only. Obliquebanded leafroller has been a serious pest for growers in this area in the past. Most have used two applications of Bt this spring for control. Control appears to have been very good, with very warm weather during the bloom and petal fall periods providing good Bt activity. Pheromone traps are also being used to monitor the flights of Bertha armyworm and Lacanobia subjuncta.

Othello - This site involves over 1350 acres and 9 growers and is located along Bench Road, southwest of the city of Othello, WA, in the Columbia Basin. The area is fairly flat, isolated from other growing districts and fairly windy. There has been no use of mating disruption here in previous years. The site coordinator is Bob Thompson. Codling moth pressure has historically ranged from low to high, and initial moth catches in pheromone traps this spring confirm this range. Although over half of the traps caught no moths in the first few weeks, there are a few blocks that have average cumulative moth catches exceeding 10 per trap. Isomate C+ is being used by most growers at close to 250 dispensers/acre, with 350-400/acre being used on many borders and in hot spots. All growers have applied an initial cover spray and will decide on later treatments on the basis of moth catch in traps.

Moxee - The Moxee site is located east of the city of Yakima, WA, along the foothills on the south side of the Moxee Valley, below Elephant Mountain. Dave Gleason is coordinating this site, which contains 670 acres and 6 growers. Codling moth pressure has generally been low but, like at other sites, there are distinct hot spots that have suffered damage in the past. Catches in traps over the first several weeks of the first flight reveal these high pressure areas, and two or more covers are planned for these locations. Most blocks have been treated with 200 Isomate C+ dispensers per acre, with higher rates used in some hot spots.

Lower Roza - This is the largest of the 1998 CAMP sites, involving 1693 acres and 23 growers in a hilly area northeast of Prosser, WA. Nan· Simone is the site coordinator with the assistance of Chuck Lochrie. The participating CAMP orchards are spread out over an area of more than ten square miles, interspersed with blocks of stone fruits, grapes, hops and field crops. This creates extensive border areas for the CAMP orchards, which is a concern where mating disruption is used. This situation is typical of many orchards in the Yakima Valley; mating disruption must be used successfully in these areas as well as in areas of contiguous orchards if it is to be used more widely in Washington. Isomate C+ pheromone dispensers are being used at close to 200 per acre across most of the project, with a few areas at 400. Codling moth catches over the first three weeks have ranged from zeroes (in nearly 50 % of the traps) to over 10 moths/week in 7% of the traps (one block averaged over 100/trap after the first three weeks!). From one to three covers are being applied for the first generation. In a departure from other CAMP sites, the growers and consultants within this site have taken on the responsibility of checking and maintaining the nearly 700 codling moth traps here (and soon to be installed leafroller traps) and reporting the data weekly to Nan· and Chuck for summarizing and distribution. Training sessions were conducted for the growers and their employees on trap use as well as pheromone installation. If successful, this approach could be a way to more economically gather some of the extensive pest data that orchard pest management programs increasingly need.

Rogers Mesa - This CAMP site is located on the Western Slope in Colorado, to the southeast of Grand Junction and at almost 6000 feet in elevation. Co-coordinators for the project are Steve Ela and Larry Traubel. There are close to 600 acres of apples and pears involved, farmed by 17 growers. There is considerable acreage of stone fruits, mostly peaches, also grown within this area. Codling moth pressure has historically been fairly low here although populations have been increasing over the past several years. Biofix was set on May 9th, and moth catch in the two weeks since has revealed a few hot spots. All growers are using Isomate C+ dispensers, most at 200 per acre with organic growers and higher pressure areas electing to use the 400 per acre rate.

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.

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