Estimated read time: 5-6 minutes
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Larry Sagers Horticultural Specialist Utah State University Extension Service Thanksgiving Point Office © All Rights Reserved
For additional information, read my column in yesterday’s Deseret Morning News
CODLING MOTH: Spray dates for the first codling moth cover spray of the year are fast approaching (seems like you just finished pruning). Due to the hotter-than-expected weather (especially the mild nighttime temperatures), the projected spray dates have moved up by 4-7 days, depending on location. The very first eggs of the year will likely begin hatching around 220 degree-days from biofix. See below for the projected beginning of egg-hatch, by location:
Boxelder County: May 10th (Monday)
Cache County: late-May
Davis County: May 12th (Wednesday)
Salt Lake County: May 14th - 20th
Utah County: May 9th (Sunday) - May 19th
Weber County: May 9th (Sunday)
To find more site-specific information, visit:
Since the beginning of time, pests robbed our food supply. Plagues of locust and other pests swarmed across ancient plains and decimated our ancestors’ food supply. Pests still destroy more than one third of the world’s food. Insects, diseases, birds, mice and a myriad of other problems attack the plants, eat the fruits and continue to destroy crops in storage.
The recent pesticide changes show future challenges for home gardeners. These how’s and why’s are for those who want to continue growing fruit without familiar pesticides. One important change in pest control is Integrated Pest Management or IPM programs that came about when scientists realized many pest problems were not being solved with pesticides.
He starts his recommendations as follows. “Backyard growers should first identify the pest causing the problem, whether they use gardening books, online sources, or USU Extension personnel. Monitor pests closely (semi-weekly or daily), using traps and visual inspections.” Monitoring pests is a major part of Steffan’s responsibilities throughout the state.
He also reminds gardeners that minor imperfections are not catastrophic. “Try to tolerate some biological activity, whether it’s good bugs, neutral bugs, or bad bugs. Try to tolerate some scruffy spots on fruits and vegetables…such spots are Nature’s “stamp of approval.
“Growers should try to use materials that are effective on bugs but less toxic to people and pets like insecticidal soap for aphids, Bt for caterpillars, horticultural oil for mites, attract-n-kill gel for codling moth, neem for leafhoppers, spinosad for caterpillars, sulfur as a fungicide, and general orchard sanitation.”
His first recommendation for general information is to access the new 2004 Home Orchard Pest Management Guide. It helps guide you through the maze of new information and names and is available online at http://extension.usu.edu/files/publications/HomeOrchardGuide2004.pdf.
I asked him for his best recommendations for one of the most serious home orchard pests, the codling moths that attack apples and pears. Controls for this pest need to start soon.
For codling moth or apple worms, his advice is, “I suggest backyard growers start using apple bags to protect against worms. These work, but they are labor-intensive. Affix the bags around the fruit when the fruit diameter gets 1/2 to 3/4 inch. Insecticides need to be applied until the apples are bagged (late-May or early-June), but from this point on, the fruit should be well-protected.”
He reminds readers, “In order to protect the apples until they can be bagged, growers will likely need to make two sprays. One spray will likely need to be made 7-10 days after petal-fall, though it could be as little as 2 days or as much as 2 weeks, depending on weather.”
Gardeners can set traps to determine when to make the sprays or they can access the Tree Fruit Advisory system (located online at http://extension.usu.edu/cooperative/ipm/). This provides information on egg-hatch so you can spray at the right time.
“The second codling moth spray should be applied 10-14 days after the first. Soon after that spray (late-May), the apples should be baggable. After apples are bagged, any remaining apples should be thinned and removed.”
Sprays to protect still work but the names are not as familiar and might be a little harder to find. “These materials (active ingredient names are provided, but formulations vary by manufacturer) available to use post-bloom on backyard apples include carbaryl, malathion, esfenvalerate, spinosad, Bt, codling moth virus, LastCall CM, pyrethrum, and permethrin.
“Most permethrin formulations cannot be used after bloom, according to their labels. Pyrethrum is a botanically derived material, often formulated as Pyganic. ‘LastCall CM’ is an effective attract-n-kill technology that uses the sex pheromone of female codling moths to attract males to a gel that contains permethrin (it can be purchased at www.ipmtech.com).
“Codling moths virus formulations are proven materials, formulated as Cyd-X and Virosoft. Esfenvalerate is a very persistent broad-spectrum material that’s new to the home-use market. It is sold as Ortho Bug B Gon and is highly effective at killing most things with nervous systems.”
Steffan’s last advice is, “Note that Imidan, Thiodan, and Diazinon are not on the list. The home-use registrations for these materials have been voluntarily cancelled by the manufacturers, but you can buy whatever is left on the shelves and use it according to the label or use any stocks that you currently have. Bear in mind that these materials are being removed because they are particularly toxic (to mammals, birds, and fish) and/or are persistent in the environment.”
For those readers who want email updates of fruit pest problems, sign up at the IPM website mentioned in the article.
For information on bagging apples and suppliers of apple bags, contact the University of Kentucky at: www.uky.edu/Ag/Entomology/entfacts/fruit/ef218.htm. The updated 2004 Home Orchard Pest Management Guide can be viewed online at this address: