Habitat loss, extreme temperatures put Missouri’s pollinators at risk

Bee populations throughout the world are declining—even right here in Missouri. Climate change has had a hand in these species’ decline, along with pesticide use, habitat loss, urbanization and harmful agricultural practices.  

Bees do much more than give you the sweet taste of honey. As pollinators, bees are responsible for the pollination of $15 billion in crops in the United States alone. 

About one-third of the food eaten in the United States comes from crops pollinated by honey bees, including apples, melons, cranberries, pumpkins, squash, broccoli and almonds. For instance, a single blueberry bee in Missouri can visit 50,000 flowers in its lifetime, helping with the production of 6,000 blueberries. 

Honeybees are the most well-known and studied bee in the world, but here in Missouri, there are about 425 other native species of ground nesting, wood nesting or parasitic bees. 

This includes bumble bees, leaf cutters, mason bees, carpenter bees, cuckoo bees, polyester bees, sweat bees, longhorn bees and squash bees. There is less knowledge and research about these native species compared to honeybees because they are harder to track.

“There has been a decline in both our managed bees and wild bees,” Tamra Reall, a horticulture field specialist for the University of Missouri Extension, said. By managed bees, Reall is referring to mostly honey bees, which are bees that are managed by a beekeeper. Wild bees are native bees that pollinate flowers and crops.

The number of managed honey bee colonies in the United States has declined steadily over the past 60 years. Dropping from 6 million colonies in 1947 to 4 million in 1970, 3 million in 1990, and just 2.5 million today. 

For example, bumble bees have typically been common throughout the Midwest—Missouri having at least six different species. But the rusty-patch bumble bee, which used to be a common species in the upper Midwest, is rarely found anymore. Its population has declined by 87 percent in the last 20 years, now likely only found in 0.1% of its historical range. It was listed as endangered in the U.S. in 2017. 

Experts are not able to distinguish exactly why the bee populations are declining but there are certain factors, especially climate change and extreme weather, that are contributing to their rapid decline.  

A primary concern for beekeepers is maintaining humidity and temperature inside the hive, which has become harder due to quickly fluctuating temperatures and longer seasons.

Evie Stone, a beekeeper from Wentzville said that “as the summers are getting hotter and the winters are getting colder, it’s harder for them [the bees] to maintain that temperature and it’s even honestly harder for us [the beekeeper] to accurately assess  how to maintain the hives.” 

Seasonal and temperature changes have a big part in the decline of native bee populations as well.

“If it’s getting warmer earlier, flowers can be blooming earlier,” Reall said. “But the bees might not actually be developing as quickly, they might not be responding to the same cues as the flowers are, so they might not emerge at the same time.”

This means less food for the bees and less flowers that are pollinated—hurting both the bees and plants alike. 

Native bee populations in Missouri are well-adapted to the, at times, unpredictable Missouri weather but as it gets even more erratic, the bees are continuing to suffer. 

Intense rainfall or long-term wet periods can affect habitats and limit the ability for bees to find food for themselves and their offspring. The hot summers can also reduce the number of flowering plants, in turn reducing the amount of food available for the bees. 

Reall describes changes in climate as a chain reaction for the bees. 

“With less plants to pollinate, they’re not going to be able to get as much food to eat so they’re not going to be as healthy and won’t be able to provide for their offspring,” Reall said. “This causes a decrease in the population and can affect the health of the next population.” 

Wild bees primarily nest in the ground but others, like bumble bee nests, can be found under vegetation or debris. Mason bees’ nests are found in hollow stems of plants or hollow tunnels of wood. 

Habitat loss has negative effects on bee populations. Native vegetation is shrinking; there are more roadways, lawns, crops and non-native gardens causing bees and pollinators allike to search harder for food and nesting sites. 

A good habitat for bees means that they have a lot of access to different flowers and their resources are connected so they are able to have a lot of food near them. It is also important to have a pesticide-free habitat. 
“Increased education is a big part of what we can do to combat bee population losses,” Reall said. “We just need to help people understand what they can do to still have a beautiful garden and still help our environment.”

Colleen Wouters earned her bachelor’s degree in science, health and environmental journalism at the Missouri Journalism School in May 2021.

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