Franchise owners from both Charlotte, NC area and the Birmingham, AL area both sent in pictures of small earthen mounds of soil that resemble ant hills, but the openings are much larger. The mounds are the result of Ground Nesting Bees making burrows in thin or bare areas of lawns and landscape beds.
There are numerous species of solitary bees that make single nests or burrows in the lawns in March into early April. These loner bees include: Membrane Bees, Digger Bees, Sweat Bees and Mason Bees. However, all these bees make similar type of burrows in which they will lay eggs. But the females from some species will make several burrows in the same area.
Most of the excavation work is done in the evening hours and the burrows can be as deep as six inches in length. The females produce a waterproof secretion with which to line the burrows to protect the eggs from too much moisture.
Pollen and nectar are collected by the females and taken back into the burrow and formed into small ball shapes that are placed on the side of the burrow.
A single egg is laid into the ball. When the egg hatches, it feeds and develops within the cell. It will emerge the following spring as an adult and a new generation is born the following March or April.
Ground Nesting Bees feed on nectar, they do not store honey like their honey bee relatives. They are important pollinators of crops and wild plants and chemical control is generally not required. They are not aggressive and generally do not sting unless threatened. The lawn can even be mowed without worrying about getting stung.
There are some aggressive species, like Yellow Jackets, that are often confused with the more docile Ground Bees. If you see numerous “bees” flying in and out of the hole, than you are probably looking at Yellow Jackets.
Ground Bees usually do not build their burrows in thick, well maintained lawns. If a lawn is consistently being watered, it will discourage the females from choosing the lawn when making burrows. She prefers dry soil and an easy access to the burrow. Following a good fertilization program to ensure a thick, dense stand of grass will go a long way in keeping Ground Bees from choosing your lawn as a home.
Having trouble with bees in your lawn this spring? Contact your local Spring-Green for more information.