Challenges Beekeepers Face in Urban Environments
Bees and the Cheyenne Urban Environment
Terrance Booth, Cheyenne Honey LLC
U.S. honey bees are still dying at unacceptable rates. Indications are that is true also for our native bumblebees. For the year ending 31 March 2018, beekeepers reported 40% of their colonies died unexpectedly during the year (Project Apis m. survey). That’s up from 33% a year earlier and is double or more the 15 to 20% that beekeepers report as acceptable (i.e., economically sustainable). Many of these losses are from urban beekeepers such as we have in Cheyenne.
Two prominent problems for urban beekeepers are the lack of a continuous and abundant growing-season supply of nectars and high-protein pollens and, improper use of insecticides—primarily the neonicotinoids and pyrethroids—by area residents. The “high-protein” qualifier on pollen leaves out much of the abundant pollens from grasses, conifers, and other wind-pollinated species. Thus, pollen (percent protein in brackets) from junipers (9%) and pines (9 to 16%) are usually not collected by honey bees, especially if they have access to birch or maple (44%); oak, pear, or rose (38 to 44%), or other pollens with similar protein levels. Bee colonies with adequate nutrition are much more likely to survive the stresses of weather, disease, and other environmental challenges than are colonies weakened by inadequate diet. If you will be planting new trees and shrubs in Cheyenne, please consider it as an opportunity to enhance the foraging opportunities for our local pollinators. Fortunately, many of the trees that Rooted in Cheyenne will be planting this spring are good pollen sources for bees, including the American Linden, Littleleaf Linden, Norway maple, Russian hawthorne and flowering crabapple.
Neonicotinoids are the most widely used group of insecticides in the world. They were developed as alternatives to organophosphates and carbamates and are less toxic to vertebrates than these older insecticides. However, because neonicotinoids are systemics they are absorbed into plants and can have a long-lasting presence in sap, pollen, and nectar whether applied to the seed, the plant, or to the soil accessed by a growing plant. Citing the critical risk neonicotinoids pose to bee populations, the European Union banned their use in 2018.
Pyrethroids are insecticides derived from the Chrysanthemum cinerariaefolium plant. Though a natural product, like castor beans and rattlesnakes, pyrethroids should to be handled with wisdom and care as it is toxic to mammals, fish, and insects—and is particularly toxic for honey and bumble bees (i.e., regardless of advertising implications to the contrary, “natural” doesn’t equal safe). As a contact insecticide it can be used at dawn or dusk when bees are less active. Experts favor using liquid formulations rather than dusts, and advise against spraying flowering plants any time if bees will be visiting.
Both chemicals are common in stores that carry pesticides. Homeowners can easily check for their presence by reading the front label on the bottle.
Besides nectar and pollen, plants also provide bees with resinous exudates that they use to make propolis—a caulking material used as a hive sealant. If the collected exudates contain insecticide the colony will be exposed to the toxic substance.
It is highly likely given the area a colony of bees may explore, that both neonicotinoids and pyrethroids will be encountered. The interaction of the two is double trouble for pollinators (see Pollinator Network @ Cornell). It should be noted that these insecticides may not kill outright, but may shorten the lives of the workers or cause disorientation so that the bees don’t return to the colony—or, field bees may return with toxic pollen which is then fed to the larvae whose loss can greatly weaken the colony as the older bees die off. Education is the key to reducing the unwise use of insecticides and sharing honey is a great way to open a conversation that might present educational opportunities. Notwithstanding the challenges presented by these insecticides and forage limitations, Cheyenne beekeepers can look forward to an improving situation through the educational efforts and community action of Rooted in Cheyenne.