The extreme weather that has battered much of the U.S. in 2022 doesn’t just affect humans. Heat waves, wildfires, droughts and storms also threaten many wild species – including some that already face other stresses.
I’ve been researching bee health for over 10 years, with a focus on honey bees. In 2021, I began hearing for the first time from beekeepers about how extreme drought and rainfall were affecting bee colony health.
Drought conditions in the western U.S. in 2021 dried up bee forage – the floral nectar and pollen that bees need to produce honey and stay healthy. And extreme rain in the Northeastlimited the hours that bees could fly for forage.
In both cases, managed colonies – hives that humans keep for honey production or commercial pollination – were starving. Beekeepers had to feed their bees more supplements of sugar water and pollen than they usually would to keep their colonies alive. Some beekeepers who had been in business for decades shared that they lost 50% to 70% of their colonies over the winter of 2021-2022.
These weather conditions likely also affected wild and native bees. And unlike managed colonies, these important species did not receive supplements to buffer them through harsh conditions.
Pesticide microdoses
Pesticides also harm bees, particularly products that cause sublethal or chronic bee health issues. Sublethal pesticide exposures can make bees less able to gather forage, grow healthy larvae and fight off viruses and mites.
However, it can be hard to document and understand sublethal toxicity. Many factors affect how bees react to agrochemicals, including whether they are exposed as larvae or as adult bees, the mixture of chemicals bees are exposed to, the weather at the time of application and how healthy a bee colony is pre-exposure.
Researchers are also working to understand how soil pesticides affect ground-nesting wild bees, which represent over 70% of the U.S. native bee population.
Junk food diets
Like many other species, bees are losing the habitat and food sources that they depend on. This is happening for many reasons.
For example, uncultivated lands are being converted to farmland or developed worldwide. Large-scale agriculture focuses on mass production of a few commodity crops, which reduces the amount of nesting habitat and forage available for bees.
And many farmers often remove pollinator-friendly plants and shrubs that grow around farm lands to reduce the risk of attracting animals such as deer and rodents, which could spread pathogens that cause foodborne illness. Research suggests that these efforts harm beneficial insects and don’t increase food safety.
As diverse and healthy bee forage disappears, beekeepers feed their bees more supplements, such as sugar water and pollen substitutes, which are not as nutritious as the nectar and pollen bees get from flowers.
Climate change is a force multiplier
Researchers don’t know exactly how climate change will affect bee health. But they suspect it will add to existing stresses.
For example, if pest pressures mount for farmers, bees will be exposed to more pesticides. Extreme rainfall can disrupt bees’ foraging patterns. Wildfires and floods may destroy bee habitat and food sources. Drought may also reduce available forage and discourage land managers from planting new areas for bees as water becomes less readily available.
Climate change could also increase the spread of Varroa and other pathogens. Warmer fall and winter temperatures extend the period when bees forage. Varroa travel on foraging bees, so longer foraging provides a larger time window for mites and the viruses they carry to spread among colonies. Higher mite populations on bee colonies heading into winter will likely cripple colony health and increase winter losses.
Research that analyzes the nutritional profiles of bee forage plants and how they change under different climate scenarios will help land managers plant climate-resilient plants for different regions.
Creating safe bee spaces
There are many ways to support bees and pollinators. Planting pollinator gardens with regional plants that bloom throughout the year can provide much-needed forage.
Ground-nesting native bees need patches of exposed and undisturbed soil, free of mulch or other ground covers. Gardeners can clear some ground in a sunny, well-drained area to create dedicated spaces for bees to dig nests. Another important step is using integrated pest management, a land management approach that minimizes the use of chemical pesticides. And anyone who wants to help monitor native bees can join community science projects and use phone apps to submit data.
Most importantly, educating people and communities about bees and their importance to our food system can help create a more pollinator-friendly world.This article is republished from The Conversation under a Creative Commons license.
Jennie L. Durant is a Research Affiliate in Human Ecology at University of California, Davis. Source: CounterPunch
