Bees are in crisis
Honeybee populations are in steep decline with potentially devastating consequences for the world’s food system and global ecosystems. Native bees, such as bumblebees and solitary bees that provide essential pollination for agricultural crops and native plants, are also in trouble. Many species are at risk of extinction. Once common butterflies, such as the monarch butterfly , are also experiencing plummeting populations. The fruits and seeds that are produced as a result of native pollinators are eaten by birds, mammals and other animals. As pollinator populations decline, the lower production of fruits and seeds is placing the entire natural system in peril.
Multiple factors contribute to the decline of pollinators, including habitat loss, pathogens (such as bacterial, fungal and viral diseases), parasites, pesticides and climate change. Studies show that different stressors can exacerbate each other. For example, most pollinators need a variety of food sources throughout the season. Due to habitat destruction from intensive monocultural farming practices, urban development and mowing and herbicide use along roadsides, there can be too few flowers available, or in the case of crop lands, few varieties of flowers, which creates dietary stress. Lack of proper nutrition causes pollinators to be more susceptible to diseases and pesticides. Most pollinators are exposed to a cocktail of pesticides and certain pesticides can greatly enhance the toxicity of other pesticides. For example, some fungicides markedly increase the toxicity of neonicotinoid insecticides. Pesticides, even at tiny doses, have been shown to greatly increase pollinators' susceptibility to diseases. Sublethal doses can also affect grooming behavior, so that pollinators have trouble ridding themselves of parasites, such as mites. Pesticides can also impact navigational and feeding behaviors, leading to more dietary stress. The combination of poor diet, pesticide exposure and diseases and parasites are creating a perfect storm that is hitting pollinators from all sides.
One group of pesticides, the neonicotinoid insecticides (also called neonics), stand out as a major contributing factor to the catastrophic loss of bees and other animals. Neonicotinoid insecticides are extremely toxic to pollinators at very low doses. They are absorbed and taken up by the plant, ending up in all plant tissues, including the nectar and pollen collected by pollinators and the seeds, fruits, and leaves eaten by other animals. These products are often applied as soil treatments in the form of granules or drenches, where they can persist for many years and continue to contaminate plants, kill earthworms and other important beneficial soil organisms, and run off into surface water where they can kill aquatic invertebrates. An analysis by a consortium of independent scientists from around the globe reviewed more than 800 peer-reviewed studies and concluded that neonicotinoid insecticides pose a significant risk to the world’s pollinators, worms, birds and other animals and that immediate action is needed. Studies conclude that pesticide application rates that regulatory agencies consider protective to the environment actually harm aquatic organisms found in surface waters (dragonflies mayflies, snails and other animals that form the base of the food chain and a healthy, clean watershed) and build up in soils to levels that can kill soil organisms.
How common are neonics?
Neonics are the world's most commonly used insecticides. They are used in agriculture, urban yards, and for termite and flea prevention in pets.
Where are neonics found?
The majority of agricultural seed in the U.S. is coated with neonics, and they are also applied directly to crops as foliar sprays. The amount of neonics applied on a per-acre basis is much greater in urban environments than agricultural lands, where they are commonly found in treatments for turf grass, trees, shrubs and flowers. The neonic products found in stores can be applied at much greater rates than agriculture and some recommend drenching the soil every six weeks – directly to flower beds.
Neonics are commonly used in the plant nursery industry, including on pollinator-friendly plants. Pollinators that visit these plants can be poisoned. The soil in the pots of treated plants can transfer neonics to private yards, where other plants can take up the insecticide. Depending on the plant and the particular neonic product, the insecticide can persist for months to years. Detectable quantities of neonics have been found in perennials and trees years after the initial application. Doses of neonics found in treated plants can be high enough to kill pollinators. Lower levels of exposure may not kill a bee immediately, but can eventually lead to death of the individual bee or colony. A number of neonic chemicals are found in common garden products . A recent study found that, when exposed to levels of neonics consistent with garden product label directions, three of four species of lady bird beetles died and two species of butterfly, the monarch and the painted lady, survived exposure as adults, but their caterpillars died from feeding on treated plants.
What is the city doing?
The city’s Integrated Pest Management (IPM) Policy directs that pesticides be reduced or eliminated, wherever possible. Most pesticides are banned on city properties. The majority of the city’s properties either have no pesticides applied or targeted and minimal quantities of pesticides (mostly herbicides) are applied as a last resort. The city’s turf grass has been pesticide-free for more than 12 years.
Only one neonicotinoid pesticide, imidacloprid, is allowed on city property, and it is restricted to specific situations when an insect pest is threatening the health or life of a valuable tree and no other options are available. This option is rarely used and the city is researching safer alternatives.
In the case of emerald ash borer, the city manager has prohibited the use of imidacloprid on all city property and all trees on public street rights-of-way. The city’s IPM and Forestry programs strongly recommend that the public not use imidacloprid for emerald ash borer, particularly soil treatments, to avoid killing earthworms and other beneficial soil organisms. Imidalcoprid has shown inconsistent results in studies for effectiveness against emerald ash borer and it poses unacceptable risks to nontarget organisms.
The city is currently undergoing a process to determine whether landscaping materials purchased by the city are treated with neonics and will be identifying sources of pollinator-safe materials.
Plant ecologists and other expert staff of the city’s Open Space and Mountain Parks, Parks and Recreation Urban Resources, and Greenways programs preserve and restore properties with native plants to provide food and shelter for pollinators and other animals.
What can you do?
Taking these three actions can make a big difference for at-risk pollinators.
1. Do not apply neonics to your yard. To avoid neonics, check labels before buying products . Ask your landscape company for detailed information about any products applied to your yard and ensure that neonics are not used. Better yet, keep your yard healthy for people and the environment by going pesticide-free and using natural lawn care .
2. Grow bee-friendly flowers that bloom from spring to fall to provide food for pollinators. To avoid poisoning pollinators, ask your garden center or nursery if plants have been treated with neonics. Support nurseries that provide neonic-free plants. People and Pollinators Action Network provides a list of local retailers who’ve taken a pledge to help protect pollinators. You can also grow plants from untreated seed or cuttings. Share untreated plants, cuttings and bulbs with your friends and neighbors!
Consider filling your garden with native plants to provide food for Colorado’s native bumblebees, solitary bees, butterflies, hummingbirds and other pollinators.
3. Take a Pollinator Safe Pledge and place signs on your property to let people know that you are providing a safe environment for pollinators. Join with your neighbors to create a Pollinator Safe Neighborhood.
Boulder recently became the first city in Colorado to have a designated Bee Safe Neighborhood. More than 200 neighbors in the Melody-Catalpa neighborhood pledged to keep their properties safe for bees. Other neighborhoods throughout the city are starting their own Bee Safe Neighborhoods. Visit the the People and Pollinators Action Network website to learn how you can join in this grassroots movement.