The Buzz in Your Lawn

How many types of bees can you name?  Honeybees, bumblebees, carpenter bees… All correct but you are 498 short of naming all the native bees that live in NC.  (Honeybees aren’t technically native, but they have ancestors who were, thus the southern buzz).   Yep, over 500 species of bees call NC home and do the important task of pollinating in our landscapes.

It’s this time of year with nature in full bloom that our native bees are on parade.  And they live very different lives than their honeybee cousins.  Most natives are solitary bees who nest in the ground (about 80% are ground dwellers).  They are NOT the same as yellow jackets – who belong to the wasp family.  Here is the difference:

Yellow jackets = wasps = large colony in the ground = hit it with lawnmower = pain

Miners = bees = single bee in the ground = pollinate your plants = food/berries

      Wasp                     Ground Bee

440px-european_wasp_white_bg  vs.   dsc_1541

I realize it is a bit hard to tell in the heat of the moment.  But these little ‘miner’ bees are one of our hometown heroes of pollination.  They need your undisturbed natural areas & understanding to turn flowers into fruit for us and the local wildlife.

Ground bees are NOT fire ants (who clearly prove Hell is real and who have a great appetite for my ankles).  The tiny, individual miner bee mounds cannot compare to the heaps of earth moved by a colony of fire ants.  But the bee mounds can be found in clusters which can be confusing.  Let’s investigate…

Fire ants = ants = large colony in a mound = goes ballistic when disturbed = pain

Miners = bees = single bees forming mounds = busy working in your yard = food/berries

   Fire Ants (aka demons)    vs.          Ground Bees

mound_sidewalk_0031_drees             multi-digger-bee-nests-2

I’ll be writing more articles in the future on our other native bees (like the shiny carpenter bee who keeps hovering at eye level when you go out on the deck).  In the meantime, learn more about our local bee friends in this timely article from the NC Cooperative Extension on the differences and importance of this species of native bees.

Pest Alert: Ground Bees Active but Do Not Threaten People or Yards

— Written By N.C. Cooperative ExtensionFrom: Steve Frank, Extension Entomologist

As I write this my front yard is abuzz with small bees. Many are flying around just above the ground while others fly back and forth to redbuds and camellias gathering pollen.

Although these bees do not generally sting I watch as mothers nervously cross the street with strollers. Neighbors pass by and comment “Watch out for all those fire ants” referring to the small mounds that dot my sparsely vegetated lawn. Others offer suggestions on how to rid myself of these dangerous beasts that are “tearing up your lawn.”

Bee emerging from its mound

The bees I am watching are ground nesting bees in the family Andrenidae. All the species in this family are solitary and nest in the ground. Solitary means they do not maintain vast hives with hundreds of workers like honeybees or yellow jackets. A single female bee builds the nest by burrowing into the ground. She prepares larval cells where eggs will be laid. Mothers provision each brood cell with a mixture of pollen and nectar called bee bread that serves as food for young larvae. After laying an egg she closes the brood cell and starts another. After completing several brood cells the mother will seal the entrance and leave the nest to begin a new nest. After a few weeks she will die leaving the next generation safe in the ground. In spring bees complete development and emerge as adults that dig their way out of the ground and forage for pollen and nectar to provision their own nests. The visual spectacle of these bees is produced largely by males who swarm over nests trying to mate with newly emerged females. The other noticeable aspect of these bees is the small mounds of dirt excavated for each nest.

bee on finger

Hundreds of small mounds and swarms of bees often trigger calls to exterminators or landscape professionals. Homeowners fear that they will be attacked and stung as they bend over to pick up the paper and they believe that the bees are actively damaging their yard and want them gone. This is not the case.

An ovipositor is the organ female insects use to insert eggs into substrates such as leaves, wood, soil, other insects, or in our case brood cells. In social insects such as honeybees, most of the females are workers that do not mate or lay eggs and thus have no need for an ovipositor. However, they do need to protect the nest from invaders. Therefore, the ovipositor of these species has evolved into a stinger to ward off threats.

Bee on Finger

With this in mind it is easy to understand why the threat of being stung by the ground nesting bees in my yard is so small. First, the bees swarming around are mostly males. Males don’t lay eggs and thus do not have an ovipositor modified or otherwise. The female bees are responsible for all aspects of nest construction and provisioning and are busy digging and foraging. Since the ovipositor of ground nesting bees is necessary for laying eggs, it is not well developed as a stinger if at all. I won’t say that you will never be stung because this would encourage some fool to torment bees until they proved me wrong. However, I have handled these bees quite a bit and never been stung.

These bees prefer to nest in dry, sparsely vegetating areas. Therefore if you have bees nesting in your lawn it is because the grass is thin and soil dry. The bees don’t make it this way they just take advantage of the conditions. If anything the bees are providing a valuable service by aerating the lawn!

The behavior and habitat preference of these bees leads us to the most promising ways to reduce their abundance in a particular yard. First they like dry soil they can dig nests in. Therefore, irrigation over the 3-4 weeks bees are active will encourage them to find other nest sites and reduce their abundance the following year. In addition, they like thin lawns with plenty of bare spots. Thus, you can take measures to improve the density of your grass to make it less appealing to bees. Native bees are an important part of ecosystems and food production. We should take steps to protect these bees or at least use non-lethal means to encourage them to nest somewhere else.