Giant Hornets of Death: Cicada Killer Wasps

For some reason in my Entomology class, my professor really liked to talk about giant ground hornets and how territorial and mad they were.  He told us they would be a trophy to add to our insect collections, but that they were dangerous to catch because their sting was so painful.   Unfortunately, I was afraid of them for years until the owner of the farm on which I work told me that the insect I knew as a giant ground hornet was the same as the cicada killer wasp, which her 9-year-old son loves to follow because of their unique behaviors.

Cicada Killer Wasp, picture source

Well, I had to do some research, and she is absolutely right - they are the same, and cicada killer wasps are generally docile and always awesome.  I actually got to know cicada killer wasps a few years ago because there were dozens of them living in an ivy patch outside the school where I used to work.  We science teachers had to research them to see if they were a danger to the students, and we decided that they were so easy-going that we'd just keep kids from walking through the ivy and that the third graders would study them as part of their Biology unit.  They loved it and no one got stung.  I wish I had connected the dots at that time between cicada killers and giant ground hornets, because I had a close encounter with a giant ground hornet on the farm last week and had a very unnecessary scare.  It would be less confusing if we all just used the scientific name, Sphecius speciosus.

Cicada killer wasps/giant ground hornets are gigantic, up to two inches long.  They are yellow/orangeish and black and variously patterned with usually black abdomens.  They are charismatic animals, and they live large on the landscape.  When they are present, you will see them, but don't be afraid.  The females are technically capable of stinging, but they won't unless they are actually handled.  I'm assuming the ones in the picture below are deceased, either that or they are in the process of stinging.

They're gigantic!  Source

Cicada killer wasps emerge from the ground in early summer.  They feed on flower nectar and search for mates.  After they mate, the females dig a burrow 1-4 feet into the ground, piling up dirt at the entrance to the ground.  The burrows are quite visible in lawns, and many lawn-farmers usually don't appreciate the mini-mole-hills.  They wasps actually prefer bare soil, since it's easier to dig through.  Males cruise around the entrance to the burrow, protecting the burrow from enemies and other males.  Their buzz is definitely bigger than their bite because males can't sting.  Still, they can and do fight fiercely in mid-air, careening around in wrestling-holds with their competitors.

After digging a burrow, the females go on the hunt.  They search for cicadas - but not to eat.  When a female finds a cicada, she stings her prey, paralyzing it but not killing it.  Then the female begins the gargantuan task of hauling the cicada, which can be three times her weight, back into her burrow where she will lay an egg on it and seal it into a chamber.  The egg hatches into a larva which then slowly eats the cicada until the cicada is a shrunken shell and the larva is huge.  Females will make several chambers in each burrow - each of her children gets its own room.  The kiddies overwinter as larvae to emerge next year.

The Wasp Finds a Victim, Source

It seems the female can tell the sex of the eggs she lays.  Her female offspring get two or three cicadas to eat, and her male offspring get just one.  Females grow much larger than males, so they need more food.

Cicada killer wasps have their own parasites that lay their eggs on the cicada killer larvae.  Velvet ants, which are wingless wasps, are parasites on parasites.  If you must fear an insect, you could choose velvet ants (also know as cow-killer ants, though they don't actually kill cows).  Velvet ants have a MAJOR sting, which I can attest to from personal experience.  If you see one, don't bother it!

Velvet Ant Source