Use of Neonicotinoids at the Chicago Botanic Garden
The Chicago Botanic Garden is committed to using the most environmentally safe and efficient methods of pest control to keep the plants in its care healthy, to maintain the beauty of the Garden, to safeguard staff and visitors, and to promote practices that sustain biodiversity.
The Garden recognizes the concerns with neonicotinoid insecticides and uses them only when necessary within its integrated pest management (IPM) program.
- We use neonicotinoids properly, and as a last resort.
- We use them very sparingly—the Garden’s average annual use of neonicotinoids over our entire 385-acre site is much less than what is typically used on a single acre of treated soybeans.
- Neonicotinoids replaced insecticides that were far worse for humans.
Chicago Botanic Garden History
For more than 40 years, the Chicago Botanic Garden has cared for the health of its living plant collection through a comprehensive plant health care (PHC) program focusing on “Best Plant, Best Location, Best Care.” This begins with proper plant selection and placement, and includes a strong focus on cultural (maintenance) practices. Within the PHC program, the Garden instituted an integrated pest management approach more than 35 years ago to manage plant pests such as insects and diseases.
The IPM program involves vigilant plant monitoring, and managing pest populations at tolerable levels. For example, we tolerate non-fatal foliar diseases on crabapples, rather than treating them with chemical sprays. IPM employs pest control methods that are least intrusive on the environment such as pruning off diseased plant parts, washing off pests, releasing predatory insects, improving soil conditions, and replacing plants with pest-resistant varieties. These, rather than chemical methods, are used whenever possible.
The overall goal of our IPM program is to minimize negative effects on the environment while achieving the desired health of the Garden’s living plant collection. We use both synthetic and naturally derived pesticides on a limited basis to do this, including an insecticide class called neonicotinoids. All pesticides are applied properly, by trained professional staff, and in ways that meet or exceed all regulations.
Background: Pesticide Evolution and Neonicotinoids in the United States
Over the years, pesticides have evolved and have become safer for people and the environment. The use of any pesticide may have potential negative environmental consequences that must be understood and managed. Unfortunately, the negatives are often discovered after the fact. In the 1960s, DDT, an organochloride insecticide, was widely used and later banned because of safety concerns and negative environment impacts. Organophosphate and carbamate insecticides replaced organochlorides, and in the mid-1990s, those were in turn replaced by pyrethroid and neonicotinoid types for the similar reasons.
Neonicotinoids are much less toxic to vertebrates and pose a much lower risk to humans and other mammals when compared to the compounds that they have largely replaced. The U.S. Environmental Protection Agency has classified some types of neonicotinoids as Reduced Risk Pesticides. Per its definition, these are a better choice because of their low impact on human health, lower toxicity to non-target organisms, low potential for groundwater contamination, low-concentration formula rates, low pest resistance potential, and compatibility with IPM practices.
Neonicotinoids are a class of insecticide chemically related to nicotine. There are many different types: Imidacloprid is the most commonly used, one of the longer lasting, and can be found in some garden centers for homeowner use. Dinotefuran is another, which is faster to degrade. These are primarily soil applied and move systemically throughout the plant. This method of application avoids drift impacts to non-target organisms that occur with spray applications.
Ease of application and greater effectiveness has caused neonicotinoid use to greatly increase since being introduced, and it is currently the most widely used group of insecticides globally. They are primarily used in the agriculture industry, where they are used prophylactically to coat the seeds of crops like soybeans and corn, or are field-applied as sprays or soil drenches. The insecticide moves through the plant as it grows, protecting it from potential insect feeding, whether or not the insects are actually feeding. Much less significant neonicotinoid use also spans forestry, horticulture, and even the treatment and prevention of fleas in cats and dogs, and termites in wood structures.
The impact of years of aggressive and expansive agricultural use of neonicotinoids has led to negative environmental impacts. Many scientific studies have highlighted the following concerns:
- Direct negative effects on pollinators and beneficial insects;
- Indirect negative effects when treatments reach non-target plants growing near treated plants;
- Persistent chemical residual in plant, soil, and water; and possible movement throughout the ecosystem.
Neonicotinoids at the Chicago Botanic Garden
The Garden always strives to use the least amount of any type of pesticide, whether synthetic or naturally-derived, and to reduce overall use each year. As a measure of our success, since 2007 the Plant Health Care team has reduced their overall pesticide usage by nearly 30 percent.
Because we understand the potential negative environmental impacts of neonicotinoids, we use them infrequently, as a last resort, and when the impacts are deemed safer to the environment than other treatments. For instance, routine use is limited to only two tree types that are treated on a semi-annual basis: white-barked birches for bronze birch borers (a fatal pest if uncontrolled) and elms in high public-use areas adjacent to the Regenstein Center for leaf beetles and flea weevils. Soil applications, like the ones we employ, minimize collateral damage: They are targeted, low-volume, and do not expose visitors and staff.
We may also use neonicotinoids as a last resort to selectively control unusual outbreaks of insects that threaten the life of a plant, such as a bonsai tree, or a group of plants. We do not use them on insect-pollinated plants, except in situations where we can prevent insect-flower contact by exclusion (such as in a closed greenhouse) or timing (so that the pesticide has cycled through the plant by the time it blooms).
As with any pesticide, proper application and a strong understanding all of the possible negative effects are key for safe, effective, and responsible use.
Chicago Botanic Garden Position on Neonicotinoids
Other aspects of the Garden’s position on neonicotinoids include the following:
- White-barked birches are currently a signature tree in several of our iconic gardens. Two-hundred-fifty mature specimens are in the Sensory Garden, on Spider Island and Evening Island, and in the areas around the Regenstein Center alone. In the future, as these garden areas are renovated, we will redesign them in consideration of the next statement.
- The Garden will avoid adding plants to our collections that are generally known to have serious insect pest concerns that may require the use of a neonicotinoid to control (e.g., additional white-barked birch, ash).
- The Garden will not use neonicotinoids in plant production areas on plants such as annual flowers that are destined for outdoor gardens. They may continue to be used on plants for indoor use (e.g., poinsettias) because neonicotinoids are safer for our staff and the public than alternatives, and we can exclude pollinators in our greenhouses. If treated with neonicotinoids, such plants will not be used outdoors.
- The Garden will continue to evaluate the use of neonicotinoids and experiment with how to further reduce future usage of this and other chemical classes, in line with our overall goal of pesticide reduction. The Garden will keep abreast of new research findings on neonicotinoids, including faster-cycling types.
- The Garden will continue to educate and inform the public and green industry professionals on the environmental concerns with neonicotinoid usage and will be a role model for safe, appropriate usage.