Many people, especially those with fruit trees to pollinate, want to keep both mason bees and honey bees in the same yard. But is that good for the bees? Will they harm each other or compete for resources? How close is too close?
In order to understand the answers to these questions, it helps to know something about the biology of both types of bees. Honey bees are great pollinators, but they have some drawbacks when it comes to fruit tree pollination. Originally, honey bees evolved in warm climates, but they gradually spread further and further north as people fell in love with their honey. They eventually made their way to Northern Europe and, later, they were shipped to the New World.
Honey Bees are Heat Lovers
Even though most of this migration was in the distant past, honey bees have retained their preference for warmth. They do not fly on cold days nor on cloudy mornings. As a result, they are often useless for pollinating fruit trees and other early flowering plants. On the other hand, many native bee species take cold weather in stride and work the fruit blossoms while the honey bees are still holed up inside. You can imagine the honey bees sitting by the fire, drinking hot chocolate, and complaining about the weather!
Mason bees (genus Osmia) are often used for fruit tree pollination because they are early bees that nest in cavities such as reeds and straws. Mason bees are efficient pollinators that can be easily propagated, moved, and stored. But don’t let the name confuse you. While there is just one species of honey bee in North America, there are more than 140 species of Osmia. Some are spring bees and some are summer bees, and some are limited to certain areas of the continent.
Differences in Lifestyle
The mason bee’s indifference to cold and cloudy weather means they forage earlier in the morning and later in the evening than honey bees. In addition, they forage on those cold, overcast days when the honey bees refuse to go outside. This adds up to many, many hours, especially in the early spring when fruit trees need attention.
A second major difference between honey bees and mason bees is their taste for sugar. Since honey bees must make honey, they seek out nectar that is very high in sugar. For example, nectar can be 60 percent sugar (some canola varieties) or as low as four percent sugar (some pear varieties). That means there is 15 times more sugar in the canola flowers than in the pears! Which would you rather use to make honey?
What that means to the orchardist is that even on a warm day, the honey bees will probably ignore your pear trees. Mason bees, on the other hand, don’t make honey. Since they use nectar solely for drinking, they are perfectly happy with a low-sugar beverage as they collect pollen for their young.
The third major difference is lifespan. Adult mason bees and honey bees both live about four-to-six weeks in the spring and summer months. But after that period, the adult masons die and their brood overwinters in a cocoon until spring. The honey bee colony, however, keeps producing new bees to replace the old ones, so the colony remains active all season.
Lifestyles Can Restrict Competition
These three differences— cold tolerance, taste for sugar, and active period — explain why your mason bees and honey bees may not actively compete with each other. In cold years, the mason bees can complete their adult phase before the honey bees even begin their work for the year. In warm years, the honey bees will most likely ignore some of the fruit trees, leaving plenty for the masons. Remember, the best plants for mason bees may not necessarily be the best plants for honey bees.
However, not all fruit tree nectar is low in sugar. Most honey bees are happy to pollinate cherry and apple trees, in which case there might very well be competition. This is offset somewhat by the fact that mason bees start foraging earlier in the day, which gives them an advantage in the cool morning hours.
In cases where you have warm weather and high-sugar nectar, the honey bees will probably outcompete the mason bees. Although masons are quick and highly efficient, honey bees make up for it in sheer numbers. So how can you help your mason bees?
Giving Mason Bees a Leg Up
To lend your bees a hand, it helps to look at another difference between mason bees and honey bees: foraging distance. Honey bees can easily forage for food in a two- or three-mile radius of their hives. In times of dearth, they often travel much further than that. On the other hand, mason bees usually forage in a much shorter radius, 200 to 300 feet, at most. Distance to the food source is a much bigger issue for the mason bees than the honey bees.
In addition, mason bees need to be near a source of water and a supply of mud. If one of their supplies is a long way off, the mason bees waste time. You want them pollinating your trees, not flying around looking for mud and water, so keep these resources close to their nesting area. I once dug a hole to plant a bush and filled the hole with water. As the water drained away, dozens of mason bees dove into the hole and began scraping the sides, collecting globs of mud. Now I do this on purpose and it works great.
So to help your masons, place their nesting tubes as close to the crop as possible. If you want them to pollinate a fruit tree, you can place the nests directly under the tree. Conversely, locate your honey bees hives further away. Obviously, the honey bees can still get to the trees, but the mason bees have an advantage because they don’t have to waste time traveling to and fro.
Do you have both mason and honey bees in your yard? What tips can you share for keeping both?