Where have all the bees gone?

Bumblebee on monarda, also called bee balm.

My son, though not yet two, is already a budding entomologist. You know the type. He notices the tiniest ants while we’re out on a walk and then squats down and parks himself in the middle of the sidewalk three blocks away from our house, refusing to move until he’s spent at least ten minutes watching and poking around at them. In Charlie’s language, there are two types of insects – butterflies and bees. Butterflies are butterflies but everything else from a housefly to a caterpillar is a bee. We’ve got a patch of anise hyssop growing in our backyard raingarden and during the summer, it was covered in bumblebees. My husband and I tried everything we could think of to keep Charlie away from the bees, but he was absolutely obsessed with them and continually tried to catch them, chase them and play with them. Luckily for Charlie, bumble bees are incredibly docile and rarely sting people so he never got hurt as he plunged into the garden screaming, “Bee! Bee! Bee!”

Though most people I know are slightly better than Charlie at identifying different types of insects, I think the vast majority still lump any flying insect that stings into the same category – bee. In reality, there are 20,000 species of bees worldwide and 250 native bee species in Minnesota alone. With the exception of honeybees and bumblebees, almost all of the other bees are solitary insects that nest alone in the ground or in stems of plants. Yellow-jacket wasps are often mistaken for bees because they are also small with yellow and black stripes but the two types of insects are not very closely related. Yellow-jackets nest in colonies in the ground and under the eaves of our houses and are much more aggressive than bees; if you’ve ever been stung by a “bee,” chances are it was actually a yellow-jacket.

Honeybees are a domesticated species of bee, not native to the U.S. but vital to many of our agricultural crops. Farmers rely on insects to pollinate one-third of their crops and 80% of this pollination is done by honeybees. Minnesota crops that are dependent on insects for pollination include apple, cucumber, strawberry, blueberry, melon, sunflower, canola, pumpkin, cranberry, squash, clover, and alfalfa. Some crops like almonds are entirely dependent on honeybees and to meet this need, beekeepers across the country ship their bees to California and back every year to make sure that almond trees in the groves actually produce almonds.

Since 1945, honeybee populations in the U.S. have declined from 4.5 million to only 2 million today and many scientists and beekeepers fear that honeybees might be on the brink of disappearing altogether. According to Professor Marla Spivak, founder of the University of Minnesota Bee Lab, we are currently losing 30% of our bee colonies every year (Watch her TED talk). Dr. Spivak cites four factors contributing to this bee die-off. First, the increase of monoculture farming means that agricultural landscapes no longer offer a variety of plants, flowering cover crops, and patches of weeds for bees to get nectar from. In addition, the insecticides used to control pest insects, especially those containing neonicotinoids, can also kill bees. The compounds from these insecticides enter plant tissues and remain there for a long time; though the  bees don’t always die immediately, the insecticides weaken their nervous systems, leaving the bees more susceptible to disease and less able to forage for food. In residential landscapes, bees suffer from the same lack of habitat that impacts other wildlife as well. Weed-free lawns are a food desert for bees and most common garden flowers have been bred for beauty, not the quality of their nectar. All of these changes in the landscape have left honeybees stressed and vulnerable to diseases and parasites that can wipe out entire colonies virtually overnight.

As a water resource professional, I find it interesting that many of the things we can do to help bees also help to protect lakes, rivers and streams. For example, incorporating flowering native plants like bee balm, anise hyssop and purple coneflower into our gardens provides a food source for bees and, because most of these plants have deep root systems, also helps to de-compact the soil, allow rainwater to soak in, and prevent erosion. We encourage farmers to use cover crops like clover and alfalfa to reduce erosion and restore soil nutrients, but both of these crops also provide excellent food for bees. In a similar manner, farmers can plant flowering trees as windbreaks along fields to prevent wind erosion and also provide bees with sources of nectar. Finally, reducing the use of insecticides in both our gardens and our farm fields can protect bees from harm and also reduce the risk that these chemicals contaminate our water.

For my son Charlie, a bee is an ant, is a fly, is a grasshopper. For the rest of us, however, it’s important to understand just how much we depend on honeybees for some of the most delicious and nutritious foods that we eat. Without them, we would have no almonds, no kiwifruit, no blueberries, no cherries, and certainly no little boys yelling, “Bee!”

Learn about the University of Minnesota Bee Lab and download a list of plants for Minnesota bees at www.beelab.umn.edu. You can also find native plant retailers and recommendations at www.BlueThumb.org. Find additional information about bees and other insects, along with research on the impacts of insecticides at www.xerces.org.