Solitary Ground Nesting Bees & Wasps: Sometimes Scary But Not Dangerous

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There are several species of solitary ground nesting bees and wasps that are active during the spring and summer months.  While they may look quite different from one another, they all share a similar lifestyle.  Kind of like people, we are all different but we live and work in the same areas (or neighborhoods).  During the warm early spring days the adults begin to emerge from their underground chambers where they have been resting over the winter.  Typically, males emerge first and begin hovering over the ground anxiously waiting for the females to emerge.  There may be several individual males flying about a certain area chasing off other males and other flying insects in their perceived territory.  They will even dive bomb and act aggressive towards people and pets as they walk through the area but this is all for show.  Their bark is much worse than their bite!  The male bees and wasps are harmless and incapable of stinging.  Only female insects can sting because the stinger is a modified egg-laying device, or ovipositor.  Without knowing this, it can be a bit unnerving to have bees or wasps flying erratically around you.  This is especially true with the large cicada killer wasps, one of the largest wasp species in the U.S.  When there are several individuals flying around the same area it may seem as if you have just wandered into a nest of giant angry hornets, but in reality you are not in any danger.  Soon, the females begin to emerge from the soil and the males jump on them like a tornado in a trailer park.  Sometimes the poor females can’t even get completely out of the ground before two or three males are all on top of her trying to mate.  Some females even get torn apart by the sexually crazed males.  Once this mating frenzy ends, the males soon die and the females get to work.  They begin by digging a hole in the ground, usually in a bare patch of soil, where she will eventually lay an egg.  Before laying the egg, she will find food for the larva to feed on once it hatches.  Bees will collect pollen and nectar to create “bee bread” that they provision the larva with.  Wasps will find other insects or spiders to paralyze by their sting and provide as a food source.

Cicada killer wasps find a cicada to sting and paralyze to stuff into the hole before laying their eggs.  Spider wasps find spiders to do this with.  They do not want to kill the prey so that it doesn’t rot before the larva has a chance to consume it.  The larva feeds on the paralyzed prey, leaving the vital organs for last so that it doesn’t die too soon.  This would not be a pleasant way to die!  The females will do this several times throughout the season.  Many times, a second generation will emerge during the late summer to early fall months and begin the process over again.  This second generation of larvae will pupate (turn into a cocoon) and stay in that stage until the following spring and emerge as adults.

The female bees and wasps are capable of stinging, but they are not aggressive.  Bees and wasps that live in colonies (like yellow jackets, hornets, paper wasps, and honey bees) are way more aggressive and more likely to sting because they are protecting their colony.  The solitary bees and wasp species are too busy digging holes, looking for food, and laying eggs to pay attention to much else.  Most people who get stung by them are those that accidentally step on one bare-footed or were trying to kill or harass the bee or wasp and it stung out of self defense.  Since they are not aggressive and do not cause damage you can just leave them alone to do their thing.  If they are active in an area that you do not want them in, there are ways to discourage them.

As mentioned, they typically prefer to nest in bare patches of soil and once an area becomes attractive to them future generations will continue to use that area.  To prevent this, alter the area by planting grass or other vegetation and eliminate the bare patches of soil.  Insecticides can be applied to those areas to kill or repel the bees or wasps, but this will only be a short term solution.  Once the insecticide wears off, the bees and wasps will return.  But, if they are not hurting anything and are in an area that is not conspicuous just let them… bee.