A few homeowners have called this past week complaining about hundreds of bees hovering over their lawns. Many are concerned about this unusual phenomenon, especially this early into the spring.
One homeowner reported that literally hundreds of small black bees were swarming low to the ground in a barren area, digging holes and making red clay mounds of soil. The primary concern was that the bees were going to kill the grass and whether these bees would sting since the residents were allergic to bee stings.
As it turns out, the bees hovering around the clay soil are a type of solitary digger bee. These bees tunnel into the clay soil to lay eggs. They look very similar to honey bees, ranging from 1/2 to 3/4 inches long and may be a variety of colors such as blue, black, copper colored or metallic brown.
Other solitary bees are mason and sweat bees.
Solitary bees are primitive without the social order of honey bees, yellow jackets or hornets. They have no caste system, such as honey bees with a queen and worker bees. They live by themselves, boring holes into the soil to lay eggs in individual tunnels.The bees often line the burrow with a water proofing secretion to protect the eggs from moisture. Ground-nesting bees generally prefer nesting in areas with morning sun exposure and well-drained soils containing little organic matter. Burrows are excavated in areas of bare ground or sparse vegetation. These bees usually avoid damp soils.A huge congregation of solitary bees boring into the ground is quite a curiosity. Large areas of soil are mounded into multiple rows of 6-inch deep holes. Borrowing bees do not kill well established lawns.
Female bees collect pollen and nectar, making a round ball about 1/4 long on the side of the cell wall. Even though the bee collects both honey and pollen, it does not make honey like its cousin the honey bee. An egg is placed on the pollen and nectar ball, providing food for the newly hatching larvae.
Solitary bees are excellent pollinators. These bees play a vital role in pollinating crops and wild plants. With all the problems domesticated bees are having with mites and other diseases, man can use all the help he can get from these docile insects.
These bees are not aggressive and they rarely sting. Avoid the nesting area for four to six weeks if possible. Once the nesting is complete, the insects leave and continue pollinating.
Bees usually bore in areas that are weak or thin. Heal-thy vigorous growth is a natural method of controlling the insect.
Cultural control methods include heavy watering or irrigation with a lawn sprinkler now during the nest-building period to discourage nesting. If the soil or location is not conducive to a healthy lawn, using ground covers or heavy mulches may be an alternative solution. Mulches may be used on bare patches caused by heavy traffic where grass will not grow.
If all else fails, Sevin dust or the liquid formulation easily kills the insect.
Darrell Blackwelder is an Extension agent in horticulture; call 704-216-8970.