Picture hundreds of bumblebee, honey bee, and other insect bodies lying dead, coating the Oregon store parking lot. The store had hired a local landscaping company to spray the area’s trees with a pesticide to rid the late spring-flowering European lindens (Tilia x europaea) of aphids – and the results were horrific.
In Jennifer Zurko’s article “Should We Nix Neonics?” published in GrowerTalks Magazine on June 27, 2014, she recounts the unintended consequences of pesticide use. Although the reduction of bee populations has been an issue for more than 20 years in North America, this particular incident has become iconic in our mind’s eye.
Passersby, gardener and non-gardener alike, who witnessed the carnage must have had difficulty clearing the image from their memories. The sickening scene especially gave visual confirmation to what bee advocates felt all along; pesticides are the reason for the drop in bee populations.
Consumers have been increasingly aware of “big box” stores selling plants treated with neonicotinoids like dinotefuran, and now they’re worried.
By purchasing plants still harboring the residue of the chemical, are we contributing to the decline of bee populations by installing the plants in our gardens?
Insecticides for Controlling Pests in Agriculture and Horticulture
Using insecticides in agriculture has greatly improved the farmers’ abilities to control insects that damage crops (and, as a result, keeps food costs down, some would argue) and while horticulturists have used the chemicals to control chewing pests from turning ornamental plants into Swiss cheese, these pesticides are a systemic tool. Pesticides, we must recognize, are incapable of limiting their harmful effects to only the insects we deem “pests.”
In researchers’ investigations into declining bee populations, experts have found a link between the use of neonicotinoids and the death of beneficial insects as well.
Neonicotinoid looks and acts like nicotine. Nicotine is present naturally in some common plants that gardeners grow every year; notably, in the large Solanaceae family, whose relatives ranges from tomatoes and egg plants to petunia, and many other herbs and vines as well as commercial plants like tobacco.
But neonictinoid in its chemical form, scientists acknowledge, is strong enough to add stress to bees, and presumably other beneficial insects. So, putting stress on their little bee-bodies makes them more susceptible to the natural parasites and pathogens that feed on our honey-makers.
The dilemma for society is: at what point do the lives of bees and other pollinators outweigh the benefit of using insecticides, like neonicotinoid?
Or, are we willing to pay more for products grown through labor-intensive Integrated Pest Management systems to have our food and flowers come out aethestically perfect? Or, accept food and flowers grown organically will look less gussied up, and less able to withstand long hauls across country for sale in grocery chains?
Mass-grown fresh food and ornamental plants may appear on consumer shelves in slightly more damaged appearances when not protected by insecticides that curtail chewing insects, for example. But for some consumers, there might never be an acceptable level of damage to insect populations who do us good; what horticulturists call “beneficials.” Protecting the beneficials is one of many reasons some gardeners have gone to great lengths to grow their fresh food in an organic manner.
Potential Explanations of Bee Loss
Bee decline is a term often used interchangeably with the phenomenon called Colony Collapse Disorder. But CCD is only a subcategory of the larger issue of bee decline and though we think of it as a North American problem, the decimation of bees is worldwide.
Researchers believe there are combinations of stressful changes that have impacted the life of bees on the planet beyond the high use of pesticides.
Although spraying chemicals certainly contributes to mass destruction especially when used wantonly and without following specific instructions, it is more likely that a combination of factors is behind the massive bee decline.
Human habits in growing plants have changed the landscape. Farmers no longer rotate their crops as frequently or leave the fringes of their fields for wildflowers; this has further shrunk the habitat and diversity bees have to forage over.
The increased human demand for nuts and fruits has put additional stress on bee populations maintained in the bee-keeping industry. Growers like those that produce almonds, for instance, use quick injections of pollinators during the flowering season.
Beekeepers may feel the pressure to move hives far afield of their original location, further putting pressure on the bees.
The natural resistance bees have is also weakened by the parasites and diseases that feed on bees. Experts view the Varroa mite and a new fungus called Nosema ceranae as causing current health concerns.
Integrated Pest Management System and Cautionary Tales
In the United States, beyond federal laws, every state has its own laws and local communities their own sensibilities; the regulations and licensing of chemical applicators (the landscapers who apply fertilizers and insecticides) vary widely.
In Oregon, the landscape applicators that killed the bees in the parking lot were found negligent and heavily fined by the state of Oregon’s Department of Agriculture for applying the insecticide to the linden trees. The users applied the spray incorrectly (while trees were flowering and bees would be pollinating) and ignored the product instructions.
The penalty for the same offense in another locale might have been less or nonexistent and some state and county governments do not regulate spraying pesticides at all.
One of the most effective systems for controlling unwanted insects while protecting the environment is the use of the Integrated Pest Management System (IPM). IPM takes the long view at controlling pests through first identifying the insect-pest and understanding the plant needing protection.
Prevention steps such as rotating crops and growing pest-resistant plants, first using mechanical controls, then using specific targeted chemicals for that insect and plant, and using foliar sprays, as only a last resort, are incrementally used.
Where aphids infest linden trees, for example, in using IPM methods, first understand the link between a spring flowering tree and pollinators like bees attracted to the plant.
A landscaper might have considered using beneficial predator insects like lady beetles where practical before first spraying the site with a chemical killer and making the environment inhospitable to the very biological insects that would benefit in the fight against aphids.
If using a pesticide, the landscaper should have waited until the flowers had faded – and used it in the lowest possible effective dose of the spray.
Shop and Grow Seeds and Plants to Help Bees
The life of a gardener includes the search for seeds and plants. For some gardeners in the electronic age, looking through seed and plant catalogs is still a favorite winter pastime and the list of ideas is always expanding.
The more gardeners become absorbed into seed and plant collecting, and shopping, the more they develop their specialized strategies. Gardeners rarely purchase all their plant material from one location or in all the same form: as seeds, small transplants, or full-grown plants.
Ferreting out how you locate plants for your garden requires you to determine what is acceptable to you. Do you support, or even want to attract, beneficial insects? Prefer only-organic or most-of-the-time organic growers? Like buying local products? Favor specialized types of flowers or vegetables?
Whatever your choices, there is much you can do to limit pesticides in your garden:
- Don’t use the chemicals yourself – or else be picky about why and when you do use pesticides.
- Shop at local plant nurseries where you can verify how their plants are grown.
- Attend plant sales put on by botanical gardens and master gardener organizations.
- Every year install some percentage of native plant species in your garden.
- Section off a space for each plant variety devoted to pollinators in your backyard.
- Create a pattern of flowering plants that will bloom in a sequential manner to increase the diversity of your landscape. This means a portion of the plants will flower spring, summer and fall.
Take a tip from farm families and build a cutting garden of flowers nearby your kitchen garden; pollinators love some of the same flowers that are attractive in vases.
How to Support Beneficial Insects While We Garden
Early in 2015, big box chain Lowe’s said they would phase out the sale of pesticides containing neonicotinoids in their stores. Whether a mammoth company, which does not themselves grow plants, can eliminate all chemicals and still obtain its plants from growers around the world remains to be seen.
Unless consumers can trace the origins of the plants purchased and can be assured that the growers did not use pesticides, citizen gardeners will have to discover the facts and maybe accept the trade-offs.
Federal, state, and local environmental laws vary around the United States, as well as internationally, though when they are strong they can lend teeth to enforcing environmental laws including the ones that protect bees.
Protect Local Bees: Buy Local and Organic
Buying a higher percentage of local plants and obtaining a substantial number of plants from seeds helps, and supporting stores whose policies and procedures advocate for beneficial insects are sound steps.
Gardeners can plant a large diverse collection of plants in their own backyards in an effort to help all beneficial insects to keeping the environment healthy.
Using the principals of integrated pest management to care for your garden is another useful step to providing a healthy smorgasbord of plants for bees to safely snuggle up against.