Sunday, July 30, 2017

Sphecius speciosus

It's a good week if you learn something new. It's an even better week if you lean lots of new things. I took this past week off to spend with my daughter which in itself was pure delight. On Monday we took our trip to the points of historical interest along the Stevenson Expressway. You can probably guess that was my idea. Tuesday was our day with Grandma. Then on Wednesday and Thursday at my daughter's request, we went to the Museum of Science and Industry and the Field Museum. There's always plenty to learn at both institutions. At the MSI with the help of two examples, I taught my daughter the concept of the Foucault Pendulum, the remarkably elegant 19th century experiment that proved once and for all the earth does indeed rotate about its axis. We learned about how cow poop can be used to provide electricity on a farm and how much poop it would take to power a laptop, two wheelbarrows full in case you're wondering. I didn't know that. We saw New York Central steam locomotive number 999, the first machine to break the 100 mile per hour speed barrier, and saw a working replica of the Wright Brothers plane they flew at Kitty Hawk. After our visit to the museum, we walked through the future site of the Barack Obama Presidential Library and saw all the beautiful trees that will be sacrificed for the project. It broke both our hearts.

At the Field Museum of Natural History we visited their terrific exhibit on the history of life on planet earth. Apparently they haven't yet read the directive from Anthony Scaramucci claiming the earth is only 6000 years old. At the Field where they still believe in science, they seem to think the number is closer to 4.5 billion. We learned all about natural selection's role in evolution, more fake news apparently, at least according to the current administration, and a little about dinosaur identification. We bypassed our old standbys the classic dioramas, in favor of a special paid exhibit the nice cashier threw in for free called "Underground Adventure." I have to admit I would have been disappointed if I had to pay extra for the exhibit which tries to simulate the experience of finding yourself below ground. On view were gigantic animatronic earth worms, mites, slugs and other creepy crawly things you'd encounter beneath the soil if you were 100 times smaller than you are now. Unfortunately the exhibit couldn't decide if it wanted to be a theatrical show intended to scare your socks off, or an educational exhibit. Frankly it didn't do either very well, but I did bring one useful tidbit of information home with me from the exhibit.

It was related to something I had learned a few days earlier, but tucked away deep in my memory banks. It had to do with an infestation of wasps in the front courtyard of our building. Talking to our building engineer, I asked him in passing if there was anything that could be done about all the stinging insects. He said "Nah, they won't hurt anything, they're not interested in you, they're just interested in the cicadas." "Excuse me?" I said. He told me that he saw these wasps digging up cicadas, about twice the size of the wasps, and fly away with them. Now I've had a lifetime respect for wasps and their potential to inflict pain, but never realized their super-human, check that, their super-vespian strength, so I attributed the story to booze. But he assured me he was stone cold sober and telling the truth.

I promptly forgot the improbable story until visiting the Underground Adventure show where they had an exhibit on animals that live part time above ground and part time below. Low and behold, featured in the exhibit were wasps of the species Sphecius speciosus that exclusively go after cicadas. The common name for the species is get this, Cicada killer.

Somehow I managed to get through nearly sixty years of life without knowing this.

It turns out the name Cicada killer is a bit of a misnomer because the wasp doesn't actually kill the cicada, at least not immediately. Instead, venom from its sting paralyzes its victim which it then carries to its burrow. I should point out here that only the female of the species has a stinger so if  you see a male cicada killer wasp it is perfectly harmless. How can you tell the difference? Males are apparently half the size of the females, and they are far more aggressive, making a show trying to defend their territory. But like a Chihuahua, their bark is worse than their bite.

Anyway the female wasp does all the cicada "killing" for the purpose of laying its egg, one at a time, on its hapless victim. Once hatched, the wasp larva starts to consume the still living cicada, making sure its food source stays alive, that is until the larva becomes fully developed, which takes about two weeks. At that point it spins its cocoon from within which it will spend the winter. Pupation occurs in spring and the adult wasps emerge in early summer to continue the cycle.

Here are some other fascinating things I leaned about species Sphecius speciosus from the website, 10 facts about cicada killer wasps:
  • The female wasps are able to pre-determine the sex of their offspring. This is important because far more females are necessary to keep the species going than males. 
  • The female will provide two cicadas for every female egg and only one for each male, as the females literally do all the heavy lifting, while the males spend their time keeping the home fires burning, fighting with other stinger-less male wasps to protect their territory, and having a little fun on the side. Hey somebody has to fertilize those eggs. 
  • Some wasps have a preference for male cicadas while others have a preference for females, no one is quite sure why.
  • Sphecius speciosus is one of five species of the genus Sphecius found in the Americas. 
  • Not all wasps of the genus Sphecius are cicada killers, but all New World wasps of that genus are.
  • The word Sphecius is the Greek word for wasp. However the Cicada killer is often mistaken for, the more aggressive Vespa crabro or European wasp, the ones that would always scare the bejesus out of my classmates and me whenever they found their way into our classroom. That wasp is of a different genus altogether. Vespa you may have guessed, is the Latin word for wasp.
  • My friend the building engineer is absolutely right, the Cicada killer wasp is not the least bit interested in human beings. A female will sting you if you step on her or squeeze her in your hand, but it is not otherwise threatened by you in the least. 
Today, inspired by the beautiful light, and a plethora of wasps in our garden feasting upon the nectar of our hydrangeas, I was inspired to go out and take some pictures of our friendly neighborhood Cicada killers:

Alas I didn't see any wasps catching cicadas today. August, the big cicada season around these parts, is almost here, when the winged bugs emerge from their own underground lairs to find a mate and reproduce, hopefully for them, before they encounter a cicada killer wasp, I've just begun to hear the classic song of summer where male cicadas serenade potential partners in a sometimes deafening fashion. Given the bumper crop of wasps this year, the buggers are in for a big surprise.

When that happens, I'll be sure to be there with my camera.

Stay tuned.

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