If your favorite summer treat is a warm, ripe tomato straight from the garden, or even if the closest you get to a tomato is the ketchup on your burger, you should thank a bee, specifically a bumblebee or mud bee.
When we think of bees, we picture usually honeybees. But honeybees are not native to the Americas- they were brought here by European settlers. Some honeybees escaped, forming wild colonies and some remained domesticated. But how were flowers pollinated before the arrival of the settlers and their bees? By native bees and other pollinators of course.
Native bees are less familiar to most people because their habits differ from honeybees. Many are not social, do not form colonies or hive, and prefer to live alone and inconspicuously. Some bees nest in the ground, or in holes in wood. Many native bees have mild stings or cannot sting at all. There are over 4,000 species of native bees in the United States and these natives, along with honey bees, pollinate 75% of the fruit, vegetables and nuts grown in this country- about $16 billion dollars worth of crops.
Clearly we need bees for more than just honey, but our bees are in trouble. In the mid-2000s beekeepers began noticing a dramatic increase in the number of honeybee colonies dying off- they named this phenomenon “Colony Collapse Disorder” or CCD. Scientists have been trying to figure out what causes CCD. Possibilities include parasites, pesticides (especially neonicotinoids), fungicides, loss of wildflower diversity, and disease. A recent study concluded that the cause is probably a complex combination of all these factors. Poor nutrition due to loss of flower diversity or exposure to pesticides can make bees more susceptible to parasites and disease.
It is not just honeybees that are suffering from CCD. Native bee species are declining too although less is known about their populations. Our native bees may not produce honey for humans, but they are crucial for pollination of our crops.
Many of our favorite plants are pollinated by natives. For instance, tomatoes can be pollinated by the wind, but to produce large and numerous fruits they need “buzz pollination.” Honeybees, though they buzz, do not “buzz pollinate.” Buzz pollination is a special behavior in which the bee holds onto the flower, vibrates its flight muscles, and makes the flower vibrate as well. This loosens the pollen and maximizes pollination of the plant. Native bumblebees and mud bees buzz pollinate, so if you want productive tomatoes in your garden, you need these species.
Plants in the squash family, such as zucchini, melons and cucumbers, are also best pollinated by natives. While honeybees do visit these plants, if you see a bee at your zucchini plant very early in the morning, it’s probably a squash bee. Squash bees look similar to honeybees, but behave differently. They get up earlier because squash flowers open early in the morning and they nest in the ground, often right under the squash plant.
We can help keep our native bees around by doing a few simple things in our own backyards. Plant a few bee-friendly plants in your garden, especially native plants which require less care and are favorites of many native bees. Avoid using pesticides when possible and when you do use them, apply carefully to avoid spraying bees. Bees need to drink and many native species use mud in their nests. Providing a source of pesticide free mud and water can be a huge benefit. You can also put up a “bee block,” simply a chunk of wood with some small holes drilled into it. This provides critical nesting sites for mason bees and other species that nest in cavities. And don’t fear, these cavity-nesting bees are not aggressive, and rarely sting, so you are not inviting trouble into your backyard.
So if you enjoy fruits and vegetables or want a lovely, productive garden, do the bees a favor- make your backyard “bee friendly” and look out for our amazing native bees. They have been doing us the favor of pollinating our farms and gardens for thousands of years. Support the bees, both honeybees and native bees- we won’t have much to eat without them!
This article first appeared in the Grand Junction Daily Sentinel on March 25, 2015.