MASTER GARDENER PROGRAM — MGs in the News
Published in The Oregonian
September 04, 2016 at 5:28 AM, updated September 04, 2016 at 5:29 AM
There’s been a lot of controversy surrounding the new class of insecticides known as neonics. Sustainable gardeners want to know more about these products’ impacts on target and non-target insects.
To help, the Washington State University Clark County Master Gardener program will host a presentation by insect ecologist Gail Langellotto on the relatively novel insecticide, imidacloprid, and share the latest data on the impacts of low-level, chronic insecticide exposure on bees starting at 7 p.m. on Tuesday, Sept. 6, at the Center for Agriculture, Science and Environmental Education (CASEE), 11104 NE 149th St. in Brush Prairie, Washington.
Langellotto studies how garden design and management either promote or inhibit natural pest control and pollination. She also serves as the state coordinator for the OSU Extension Master Gardener program.
The event is free and there is no registration. For more information, 360-397-6060 x5738 or erika.d.johnson@wsu.edu.
Washington State University Clark County Master Gardener volunteer, Susan Cox wrote this article:
Most of us live in a world where food almost magically appears in our supermarkets and farmers’ markets. We don’t have an opportunity to see what it takes to grow the produce we enjoy.
Until recently, we haven’t needed to think about an essential component that makes some of our favorite produce grow: pollinators, like birds, bats, beetles, butterflies, and especially bees.
Many plants – tree fruits (like apples, pears, and citrus), berries, cucumbers, melons, and squash – can’t produce unless they are fertilized, so pollinators must move pollen and seeds from one plant to another. They also assist produce that can otherwise pollinate through wind, like tomatoes, eggplant, and peppers.
It’s estimated that at least a third of the world’s agricultural crop production relies on pollinators. Bees are an important contributor, with one crop – almonds – depending entirely on bees for pollination, and blueberries and cherries close behind at 90 percent.
Washington’s apples are also highly dependent on bees. So it’s concerning to know that bees have been disappearing in a phenomenon now named Colony Collapse Disorder (CCD).
From the USDA’s Agricultural Research Service: “The main symptom of CCD is simply a live queen bee with few if any adult honey bees present and no dead ones in the hive. Often there is still honey in the hive, and immature bees are present.”
CCD is a complex problem, and no specific cause has been identified despite ongoing research. One group of pesticides under scrutiny as a possible contributor to CCD is the neonicotinoids, or “neonics” as they are often abbreviated.
In addition to death at higher levels of exposure, bees with lower exposure experience reduced reproduction, difficulties with learning and memory, and difficulties finding their way back to the hive. Evidence indicates residue can build up in the hive as bees return with contaminated pollen and nectar. Some European countries have banned neonics in agricultural use because of these concerns.
Neonicotinoids are water soluble systemic agricultural insecticides that resemble nicotine. As systemics, they move throughout the entire plant as water does, so, even when used at lower levels, they are effective at killing insects that pierce or suck the plant’s tissues.
Their systemic nature means there is less exposure to the environment (which makes them less toxic to humans and animals), but unfortunately it makes them more dangerous to pollinators since the pesticide permeates the entire plant, including its pollen and nectar.
Most bee poisoning incidents here involve four chemical families with high residual toxicity (lasting greater than eight hours).
In addition, to neonics, organophosphates (including diazinon and malathion), N-methyl carbamates (carbaryl/Sevin), and pyrethroids (including deltamethrin, cyfluthrin, and lambda-cyhalothrin) all have extended residual toxicity (ERT), meaning the product remains poisonous to bees for a longer period of time.
Neonics to watch out for include acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam (which has a troubling 7-14 day ERT). Over 450 products containing neonics are approved in Washington, with about a third of those approved for home or garden use.
In general:
- Don’t apply pesticides on or near blooming plants, even if they are weeds. Products can drift in the wind, so it is important to look beyond the immediate area being treated.Don’t use pesticides on or near standing water, which bees use in the hive for temperature and humidity modification.
- Do read and follow precautions on pesticide labels and particularly watch for residual toxicity, which can last as long as a week or more. Unfortunately, products intended for home use may not include specific precautionary statements for bee protection, so research product ingredients before use. It’s important to note that even some products approved for organic gardening can be dangerous to bees, including rotenone and spinosad.
- Do look for alternatives to pesticide use in the home or garden. Integrated Pest Management techniques offer safe alternatives to chemical applications.
Pesticide regulations in Oregon can be found at oregon.gov/ODA/PEST/Pages/AboutPesticides.aspx and in Washington at
agr.wa.gov/PestFert/Pesticides/LawsRules.aspx
— Susan Cox