|Vol. 2, No. 10||September 1, 1997|
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.
"Attract and Kill" for Codling Moth: Sirene® CM
Pheromones have been used for several decades in apple and pear orchards, first for pest monitoring and more recently for mating disruption, particularly of codling moth. A new control tactic using pheromones for codling moth control is pending registration, and should be commercially available next year. This new product is called Sirene® CM
Sirene has been developed over the past decade by the Swiss chemical company Ciba-Geigy (now part of Novartis). Sirene uses the "attract and kill" concept to reduce adult male codling moth numbers, with a resulting decrease in mating, fertile eggs and infested fruit. Sirene CM is formulated as a thick, sticky, black substance that is tar-like in appearance and contains 0.16% codlemone and 6% permethrin, a fast-acting synthetic pyrethroid insecticide. Using hand applicators developed specifically for the purpose, the material is applied as high as possible in trees as droplets, 50 to 100 mg by weight, to branches or scaffold limbs. With trees of about 13 feet in height or less, about 1200 droplets are recommended per acre. The total amount applied and the number of droplets per acre may be increased with larger trees or high codling moth population pressure.
Sirene droplets act as a sort of pseudo-female, luring in males with the release of codlemone. Attracted to the droplet, the male attempts to mate and contacts the insecticide, in the process picking up a lethal dose of permethrin. A Sirene application effectively attracts and kills males for at least 5 weeks, though data in Washington this year showed that droplets have been attractive for up to 8 weeks when placed in traps. As with other control methods, it is important to target application for the first generation to get the best control. Like mating disruption, the first application needs to be made by the time the first moths fly (biofix). Use of Sirene CM for second generation codling moth control may allow growers in many blocks to eliminate late season insecticide applications and residues on fruit. This method should integrate well with the use of insecticides for codling moth control, including insect growth regulators; in fact, supplemental control with insecticides is recommended with higher pressure situations.
The first successful field trials were conducted with Sirene CM in 1988 in Switzerland. A key to the progress of this technology was the development of a new liquid UV light-absorber which, added to the formulation, protected the pheromone from breakdown. Despite initial success, product development was slow for codling moth, so the first commercial attract-and-kill formulation was Sirene PBW, developed for use in Egypt to control pink bollworm in cotton. Further trials with Sirene CM led finally to its registration in the fall of 1996 in Switzerland. Small plot trials with Sirene CM were conducted in the Pacific Northwest in 1995, and again this year in Washington. Registration by the EPA is expected before the 1998 growing season.
In Swiss trials, two Sirene applications for the first codling moth generation were compared with other treatments, and generally provided equivalent control. In two low- to moderate-pressure blocks, the Sirene treatments averaged 0.2% damaged fruit at harvest, versus 2.3% in the untreated portions. In a high pressure situation, the Sirene treatment had 3% damage by the end of July, while the check had 55% infested fruit.
In two more trials, Sirene was compared with two insecticide applications for the first generation; at harvest, the Sirene blocks averaged 0.4% damage, versus 0.1% in the insecticide blocks. Mating disruption was compared with Sirene in another trial with moderate codling moth pressure. By harvest, the 4-acre Sirene block had 0.5% infested fruit and the 10-acre mating disruption area had 0.7% damage.
The initial small trials in the Pacific Northwest were done by IPM Technologies of Portland, OR, and had promising results, similar to those found in European orchard trials. Three applications of Sirene CM per season almost shut down catch in pheromone traps and reduced fruit damage to 2.3%, down from 15% in the control. Field trials in 1997 are being conducted in Wenatchee by Dr. Jay Brunner of WSU.
The attract-and-kill approach, using Sirene CM, is distinguished from codling moth mating disruption in several ways. It may be more effective than mating disruption in small blocks of less than 10 acres. Sirene is recommended for application to a minimum block size of 2.5 acres, although, like mating disruption, effectiveness increases with larger blocks. Sirene should also be less affected by conditions such as steep slopes, uneven canopies, irregularly-shaped blocks or windy conditions, all of which can limit the success of mating disruption. In Europe, they have found Sirene CM to be effective in controlling or reducing codling moth populations considered too high for mating disruption to function alone: in Switzerland, the use of mating disruption alone is not recommended when fruit damage the previous year exceeded 0.5%. They have also found that Sirene CM tends to provide more reliable control, with any population increases being gradual, unlike the occasional sudden appearance of damage they have experienced with mating disruption.
Like mating disruption, the use of Sirene CM leaves no residues on the fruit and can allow significant reductions in insecticide use. The labor requirement for two Sirene applications is similar to or somewhat higher than that needed to install pheromone dispensers in an orchard. With both methods, moth catch in standard pheromone traps with 1 mg lures is shut down, and visual surveys for fruit damage are recommended. "Super lures," often septa with 10 mg of codlemone, have proven useful in mating disruption blocks; a similar approach to monitoring codling moth may be needed in Sirene-treated blocks. Sirene could be used as a supplement for mating disruption, with applications being made to orchard borders, hot spots and/or just prior to peak moth flight.
Many questions remain about the use of Sirene CM in Northwest apple and pear orchards, despite the imminent registration of this product. The question of cost will be answered by next spring; at this point the answer is that it will be priced "competitively" (of course!) with other codling moth control methods. Orchard trials will continue, and our knowledge of this new and potentially valuable pest control tool will increase rapidly. Further information can be obtained from Phillip Kirsch of IPM Technologies, Portland, OR (503) 288-2493.
Reliance on the use of broad-spectrum insecticides to combat arthropod pests of apple in the Northwest is being challenged, as reasonable alternatives become more widely available. Growers are often reluctant to abandon conventional pesticides for alternatives perceived as having a higher risk of failure, but as pressures from regulatory agencies and the public to decrease pesticide usage mount, new technologies will continue to be advanced.
Researchers connected with SARE (Sustainable Agriculture Research & Education) are investigating the changes that occur over time to the composition of the arthropod fauna in apple orchards where broad-spectrum insecticides (BSI) are being used, and in those orchards not using BSI. Special attention is being given to the effects of BSI on the parasites and predators of the target pest species. Beginning in June of 1996, pitfall traps were set in the ground in six Red Delicious apple orchards, five located in Washington (Bridgeport, Chelan, Orondo, Yakima, and Wapato), and one located in The Dalles, Oregon. Each orchard contains two 10-acre designated plots, one managed conventionally (C), and one managed without BSI (N). Pheromones are the primary control for codling moth (CM) in the N blocks. Other control measures in the N blocks include tebufenozide (an insect growth regulator), Bacillus thuringiensis (Bt), horticultural oils, and augmentative releases of parasitoids of codling moth and leafroller larvae.
Analysis of the collections from the pitfall traps for each of the two treatments shows that several potentially important mobile arthropod predators are consistently trapped in significantly higher numbers in the N blocks of all orchards. Ground beetles (Coleoptera: Carabidae), spiders (Aranae), centipedes (Chilopoda), harvestmen (Opiliones), and earwigs (Dermaptera: Forficulidae) are all predators large enough to feed on lepidopteran and homopteran pests of apple. Less mobile invertebrates, such as mites, slugs and snails appear to be less affected by the different management strategies, and are found in slightly higher numbers in the conventional sites. One explanation for this phenomenon might be that the more mobile invertebrates make more contact with the applied insecticides through their movements.
Ground beetles are a special focus of this investigation, as several species of ground beetle have been shown to be predators of fifth instar codling moth larvae as they descend from the trees to search for sites to construct hibernacula. Fifth instar CM searching activity occurs during night-time hours, which coincides with the peak activity of the ground beetle species that attack it. It is not yet known whether ground beetles will also feed on a fifth instar CM larva once it has spun a cocoon. Experiments are currently underway to determine the ground beetleís abilities in this area. Increased numbers of ground beetles in orchards not using broad-spectrum insecticides may prove to be an effective means of decreasing the numbers of CM overwintering in the orchard, and thus decrease the number of first-generation CM emerging in the orchard the following spring.
Pheromone-based pest management systems are proving to be successful at controlling the codling moth in apple orchards, allowing growers to reduce their reliance on the use of broad-spectrum pesticides. Understanding the change in orchard ecology when BSI are removed will help growers adapt to new technologies.
Growers and consultants wishing to receive funding to establish a codling moth areawide control site have until September 30, 1997, to submit a proposal to the USDA-ARS lab near Wapato. Funds are available once again to provide up to $40,000 each to at least five new sites in 1998. This money is to be used to hire people for the monitoring and coordination of the site, and to purchase pheromone traps and lures and other monitoring supplies. This program will also be funding new sites again in the 1999 season.
In addition, sites will be favored that have a strong likelihood of continuing the areawide control approach for more than the one year for which funding is provided by the USDA-ARS. Sites will also be preferred from areas where experience with mating disruption for codling moth control is limited and where mostly small to mid-sized growers are involved (less than 100 acres each).
Proposals need to be received by September 30 at the USDA-ARS Lab near Wapato, WA. Address to:
Dr. Carrol Calkins
Yakima Agricultural Research Lab
5230 Konnowac Pass Road
Wapato, WA 98951
For more information, call Dr. Calkins at (509) 454-6570; or Ted Alway, WSU Cooperative Extension, Wenatchee, at (509) 664-5540.
Tree fruit pest management is in the midst of a period of rapid change. We could soon lose, as a result of the Food Quality Protection Act, many of the pesticides that apple and pear growers have relied upon for orchard pest control. Key pests, like codling moth and leafrollers, are showing increased resistance to some insecticides. At the same time, many new pest control materials and strategies are becoming available. This growing list includes mating disruption for codling moth and, now, leafroller; insect growth regulators, like Confirm® and Comply®; other new chemistries, including Success® and Pyramite®; and "attract and kill" technology (Sirene CM®).
How do we make sense of all this? What will an effective pest management program look like in two years, or even next year? Where can we find the answers?
To help address these questions and concerns, three orchard pest management workshops will be held in Washington next January. "The New Face of Orchard Pest Management" is the tentative title for the day-long workshop in which consultants and growers will be able to learn of the most recent and valuable developments in orchard pest control. Included in the format will be a panel discussion involving local consultants and growers, and there will be plenty of time for questions and answers. Extensive educational materials will be provided, as will lunch and refreshments. There will be a modest registration fee, and attendance will be limited to facilitate asking questions and discussion. Check the Good Fruit Grower and this newsletter for information on advance registration.
Three workshops are planned for January, 1998: Okanogan on January 13, Wenatchee on January 14, and Yakima on January 15. These workshops will be packed with up-to-date and practical information you wonít want to miss; set aside these dates today!
Ted Alway, Editor
Phone: (509) 664-5540
Fax: (509) 664-5561
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
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