NZ Wasp Gets Evicted

    Spring has sprung in southern Oregon and the wasps are dancing under the eaves. While I had planned to discuss the possibility of insects sustaining the ever-growing human population, I recently remembered a wasp story from my travels in New Zealand. I may post about bugs as food later on, but in the meantime, you can check out Megan Miller’s TED Talk about insects as a food source here.

    This is from a weekly email I sent to family and friends while traveling. I was living and working on a pear orchard in Motueka at the time, located in the northern coastal region of the South Island:

A few out-of-the-ordinary events have occurred, one of which I have to share because it is probably the freakiest phenomenon I have ever discovered in the natural world. For a few days I had heard a whining buzz near the sink in the kitchen and eventually discovered the source: a black bee-like insect hanging out on the over-sink water heater. There is a transparent gauge running up the front of the tank displaying the amount of water inside, which showed it was about half-full. Upon closer examination, the bee seemed to be covering a small, square opening near the top of the gauge with yellowish mud-like "stuff." I was a bit weirded out by this invasion, so I grabbed the noisy bee with an oven mitt and put her outside. 

I then studied the yellowish square and thought that maybe the bee was making a home there. I didn't know what I might find inside, but some dark curiosity overcame me and I began to unblock the hole to take a peek... until I unearthed a black, hairy leg poking out of a corner. I backed away, though I wasn't sure if I had imagined this or not. I didn't really want to surprise a bee and get stung (I am one of those people who reacts badly, puffing up like a blowfish). 

Still, I wasn't done experimenting, so I decided to implement a more indirect course of action. When the water heater is filled, the gauge directly fills with it; my plan was to unblock the yellow seal on top of the gauge by slowly filling the tank, thereby avoiding direct contact with whatever was inside. I turned on the water and watched as it began to creep up the gauge (I proceeded cautiously so there wouldn’t be an explosion out of the hole in the top). 

Despite my care, this still happened. The water flow stopped briefly before all the contents of the nest came spewing out at once. Some of it went into my hair, which is horrible, considering what was inside.

Spiders. Intact, adult orb web spiders (Eriophora pustulosa). 

 

I expected maybe some more bees or pupae, but not this. They were not enclosed in any casing or nibbled on... they all appeared freshly-dead. Many of them were a green, shimmering color with long back legs. I learned I had disturbed the nest of a mason wasp (of the family Eumeninae), a species native to New Zealand. They make a whining sound as they process the nesting material (mud) and are sort of black in color. 

 

Why all the dead spiders? Well first of all, they weren't dead. 

Yeah. 

They were alive, but unable to move having been paralyzed by the mama wasp. It gets better: she places the immobile spiders in various compartments of her nest, each housing an egg (often placed under the skin or directly on the spider(s)). When her eggs hatch, the larvae begin to eat the spiders, starting with the non-vital bits in order to keep them alive and fresh for as long as possible. This behavior of stockpiling food is known as mass provisioning.



 Had I experienced this story without any knowledge of science or understanding of the natural world, I might think that this wasp was pure evil, possessed by some kind of sick demon. From a human perspective, it seems pretty messed up for a living creature to be eaten alive while paralyzed. 

But if this process isn't amazing, I don't know what is. This creature has evolved to survive in this unique way on a planet where food is uncertain. I'm fortunate to live in an age where information is so readily available that I can actually look up this phenomenon and figure out what is going on.

We can all explore the world right in front of our eyes between the tools of science and a willingness to understand that everything in nature has a niche. For an observation to be written off as "too wondrous for mortal understanding" would do this planet a great disservice, as lack of understanding leads to uninformed decisions that harm life, human or otherwise. At the same time, to assume that something that seems "evil” to humans--like being paralyzed and eaten alive--is also “evil” by nature, would also be misled.  

May we all reflect on our own niche: the part we play in the environment in which we live, with the resources we have, and appreciate the wonder that is all around us without rash judgement.