By Amy-Lynn Albertson
N.C. Cooperative Extension

Have you noticed bees flying low over your grass and digging small holes? If so, you might have digger bees. These solitary bees nest individually in the ground without forming colonies like honeybees. Digger bees vary in size from ½ to ¾ inches and may be colored blue, green, copper or metallic reddish-brown. Solitary, ground-nesting bees play a vital role in ecosystems, especially in pollinating crops and wild plants. They are valuable pollinators and should only be destroyed for compelling reasons.

During the evening, female digger bees dig burrows that can reach six inches deep, creating small mounds of soil at each nest opening. Each hole belongs to one female, who collects pollen and nectar during the day to create a food ball within the burrow. An egg is laid on this pollen ball in April or early May, and the larva feeds on it before emerging the following spring.

Ground-nesting bees prefer sunny areas with well-drained soils and usually avoid damp environments. Solitary bees rarely sting, and there is no mass attack like that of honeybees or yellow jackets. You can continue mowing and other outdoor activities with little issue. However, if there are large populations, you might prefer to avoid the area for four to six weeks during their nesting period.

To discourage nesting, consider heavy watering or tilling the soil. Dense turf establishment is also effective. If your lawn isn’t healthy, you might opt for ground covers or heavy mulches.

Carpenter bees

Carpenter bees, another type of solitary bee, create nests by drilling holes in wood. The female chisels out a nest up to 18 inches deep, adds a pollen ball, lays an egg and seals each chamber with wood dust. She passes away after laying her eggs in late spring to early summer. The offspring emerge as adults in late summer, overwintering in the nest until spring.

Protecting your home from carpenter bees is challenging, as they will drill into any dead wood. Treating wood with paint or pesticides is often ineffective. Using composite materials for decking can help, though it may be costly. Alternatively, you can try to lure them away from your porch by creating a more attractive alternative. For example, you can build a wooden trellis some distance from your house and cover it with flowering plants. While there’s no guarantee this will work, you’ll at least end up with a nice trellis.

For more information about bees or horticultural topics, contact the Rowan County Extension Office at 704-216-8970 or go to http://rowan.ces.ncsu.edu.

Amy-Lynn Albertson is director of the Rowan County Extension.