March 1, 2002
Vol. 4 No. 1
Orchard IPM Update Debuts
"Orchard IPM Update" is a newsletter that will be produced at least eight times a year, addressing many topics related to apple and pear pest management in the 21st century. It will be available online only (http://entomology.tfrec.wsu.edu/stableipm/), making it is easy, fast and inexpensive to produce and distribute. If you are reading this, and don't have access to the Internet, then someone has printed it out for you (which is fine, as we just want to share the information!) I (Ted Alway) will be the editor and writer-in-chief, and will be seeking out others to create articles of interest. I am working part-time at the Washington State University Tree Fruit Research and Extension Center in Wenatchee. Much of my work involves coordinating the monitoring and investigations occurring in the Areawide II apple and pear sites (more below). This newsletter is part of a larger effort to inform apple and pear growers of how to effectively and economically control orchard pests and utilize many of the new tools and techniques now available. If you would like to receive a notification via email each time a new edition is produced, just send me an email message.
IFAFS/RAMP and Multi-tactic IPM
A large new research and educational effort is underway in the Western states with regard to orchard pest management. An all-star group of entomologists from three state universities (Washington State University, Oregon State University and the University of California-Berkeley) and the US Department of Agriculture (Albany, CA and Wapato, WA) are collaborating in this multi-state, multi-institutional, multi-disciplinary, multi-year and multi-tactic project; this is almost the same group that, from 1995 through 1999, were involved with the successful Codling Moth Areawide Management Project, known (affectionately) to many growers and consultants as CAMP. This new project has received funding from the USDA-CSREES (United States Department Of Agriculture - Cooperative States Research, Education and Extension Service) (that's why we use abbreviations!), or, more specifically, two programs, the Initiative for Future Agriculture and Food Systems (IFAFS) and FQPA Risk Mitigation for Major Food Crop Systems (RAMP) programs.
Nearly $4 million will be received over a four-year period from the two programs, supporting research and implementation projects designed to address a number of objectives:
Visit the project's web site for more information.
"Areawide II" has been adopted as the title for the implementation part of this project. We are applying, in commercial apple and pear orchards, what we've learned about new pest management "tools", e.g. new pesticides, mating disruption, monitoring techniques, enhanced biological control and more. We are following these demonstration orchards for four years to monitor changes in pest and natural enemy populations over time. This "multi-tactic" approach should be more stable, providing better pest control over more years, than the more pesticide-reliant approach that has characterized orchard pest management for the past century. We are also mindful of cost-effectiveness, tracking how the cost of these new, more selective programs compares with the standard programs more commonly used. Finally, by demonstrating how soft pest management programs can be used, we are preparing growers for a (near) future without several key insecticides, particularly organophosphates like Guthion and Imidan.
Twenty-one different orchard sites were established in 2001, Year One of the four-year study.
|A6||West Yakima||Spur RedGala/
One-half of each orchard was treated conventionally, including receiving treatments of organophosphate insecticides as needed (OP). The other half controlled pests without the use of any OP insecticides (NON-OP). The NON-OP half of the orchard controlled the major lepidopteran pests (codling moth, leafrollers and lacanobia fruitworm) with pesticides such as Esteem (pyriproxifen), Intrepid (methoxyfenozide), Success (spinosad) and Avaunt (indoxacarb). Other pests were controlled with registered NON-OP insecticides such as Provado (imidacloprid) and Carzol (formetanate hydrochloride).
Several different methods, some established and some experimental, were used to monitor the lepidopteran pests. Codling moth were monitored with traps baited with both a high-load pheromone lure (Super Lure Bubble Cap by Pherotech, Inc.) and a lure containing a non-pheromone, kairomone attractant from TrÈcÈ, Inc., called the DA-lure. This latter lure is based on an odor derived from pear fruit, and is attractive to both sexes; more on this new lure in the next issue of this newsletter. Both pandemis and obliquebanded leafrollers were monitored using traps baited with a standard (1 mg) and low load (0.1 mg for PLR, 0.01 mg for OBLR) pheromone lures. In addition, a food-based attractant for leafrollers containing acetic acid was used in each orchard. Lacanobia fruitworm (Lacanobia subjuncta) was monitored with both a pheromone lure and a non-pheromone lure containing a mixture of acetic acid and isoamyl alcohol (AAOH).
Field monitoring for damage, of both fruit and foliage, was done at key times throughout the season in each orchard. Surveys were made in each block for the amount and location of damage by each of the lepidopteran pests. Bins of fruit were checked for damage by lepidopteran pests and other insects during harvest.
Six pear orchards (each from 15 to 20 acres in size) participated in the AWII program. Each orchard was divided into four treatments:
The objective of the AWII pear program was to determine whether eliminating certain insecticides known to be disruptive of many natural enemies in pear orchards could improve the biological control of several key pear pests, including pear psylla, spider mites and grape mealybug.
Each orchard was monitored with pheromone traps for CM and leafrollers as described above. The DA and AA lures were also used in the pear orchards for monitoring CM and leafrollers, respectively. Every two weeks, each of the four treatments in each pear orchard was monitored for pear pests and natural enemies with a beating tray sample, and leaf samples were collected from each treatment from fruiting spurs (mid May through August) and top shoots (mid-June through August). These leaf samples were brushed and counted at the WSU-TFREC or the USDA-YARL.
AWII Results from Year OneAPPLES
The populations of the key pests (codling moth, leafrollers and lacanobia fruitworm) varied greatly among the 15 apple sites, but in no site or treatment was there any unacceptable damage. In fact, the amount of damage by leafrollers (foliage and fruit) was significantly less in the NON-OP portions of the apple blocks. Feeding by lacanobia was also lower in these areas. Codling moth damage was no different between the two treatments, despite some blocks having surprisingly high populations. Growers responded to the high CM catches in traps, where they occurred, with pesticide applications.
The main difference in sprays between the two treatments was in the codling moth control program. The conventional (OP) half was commonly treated with Guthion, while the soft (NON-OP) portion was generally sprayed with Intrepid, with a few growers also using Esteem. Although the Intrepid was timed for CM, its residual activity often provided control of leafrollers and lacanobia as well. Although there was no significant difference, the soft treatment-blocks tended to receive a few more treatments, with, for example, three Intrepids being applied in the soft half versus two Guthions in the conventional half. Likewise, the cost of the soft programs tended to be a bit higher ($250/ac average for 15 soft blocks, versus $220 in the 15 paired conventional blocks).
Secondary pests (aphids, mites, leafhoppers and leafminers) and natural enemies (predatory mites, aphid predators and leafminer parasites) were monitored in all blocks and no differences were found between treatments. With the continued use of selective insecticides over several years we will be watching closely for any trends in pest and natural enemy numbers.PEARS
There were significant differences in pest and natural enemy numbers between the sites but not between the treatments. The North Central Washington sites tended to have more psylla and natural enemies than the Yakima sites, but no blocks suffered significant damage. Grape mealybug was found only in the NCW orchards. The treatment effects (Agri-Mek +OP, Agri-Mek -OP, etc.) were confounded by the spray protocols used. Although 2 of the 4 treatments at each site did not use Agri-Mek for pear psylla, most of these blocks used other, disruptive psyllicides (e.g. Pyramite, Provado or Actara), thus reducing or eliminating the natural enemies we hoped to conserve. This situation is being addressed in 2002 by dividing each orchard into only two treatments: conventional and selective. The conventional treatment-blocks will use Agri-Mek, Pyramite, chloronicotinyls (Actara, Provado) and/or OPs as needed; the selective blocks will use none of the above materials and will instead use oil, Surround (pre-bloom only), Esteem, azadirachtin and other materials and timings that will have minimal impact on predators and parasites of pear psylla, grape mealybug and spider mites.