UNAWARE OF SCIENCE: TARANTULAS VERSUS CHUPAHUESOS

By Juan Montoya

Rainy days sometimes take me back to when I was a boy attending Cromack Elementary in the Southmost barrio.

We used to live literally on the other side of the railroad tracks (now gone) north of the old Lopez Supermarket where the new Melrose shopping center is now. 

Today, there's a police substation across from Southmost Road from the spot I'm remembering.

In those days (1964?), there was no Lopez, no police substation. Nor was there the water tower that was torn down to make room for the satellite Cameron County Tax Assessor-Collector office. In fact, there was only the old Ruenes Drive-In across 30th Street from Cromack, and an overgrown empty lot across Southmost that stretched out to the railroad (now abandoned), where the numbered streets (28th, 29th, 30th) continued after the interruption by the empty lot and railway grade.

We used to walk from our house on the north side of the railroad, through paths across the large empty lot, cross Southmost, and to Cromack. The subdivision where we lived was noteworthy because all the roofing was blue, so they were called las casas azules.

Joe Hinojosa (hey, coach!) used to live there as did the Walkers (Zambranos) , the Zamarripas (Betin), Raul Salinas (ROTC), and Tony Rocha (La Peca's son). When it rained, we would sometimes come across large tarantulas that crawled out of their flooded holes and onto the path. They were terrifying, some black, huge, usually with their front legs poised for attack, some with orange tints, others almost yellow. We would, of course, throw stones or dirt clods at them to kill them or scare them away.

But soon, we noticed that large bluish, almost black wasps with opaque, rust colored wings would sometimes tangle with the tarantulas and were marveled that such a small wasp could take on and dominate the large scary spiders. We called them chupahuesos to indicate their lethal power.

Soon, as kids are wont to do, we developed a game to make them fight.

One of us (I don't remember who) got a clear glass container with a lid and used a branch to knock down one of the fearsome wasps and trapped it in the jar. 

Then we looked for a tarantula hole, opened the jar and turned it upside down to let the wasp crawl out and go into the hole. It didn't take long for the confrontation inside the hole to occur. Within minutes, the wasp would emerge dragging the comatose tarantula with it. We, of course, were thrilled and did it over and over until we grew tired of the game and went on to other things.

What we didn't know at the time was that the wasp going after the spider in the hole was as natural as mosquitoes biting you in the South Texas evenings. Much, much later, while browsing through some book I got from a thrift store, I came upon an article that described the relationship between the wasp (called a tarantula hawk wasp, not a chupahuesos) and tarantulas.

Alexander Petrunkevitch wrote in 1952 in an article called "The Spider and the Wasp" exactly why it was that these particular wasps hunted these particular tarantulas. Petrunkevitch in his article describes the natural relationship between these two insects. The digger wasp that Petrunkevitch was talking about seeks only a particular species of tarantula (not all wasps seek the same species of tarantula) when it is time for her to lay her eggs (it is only female wasps that do this).

According to the author, the wasps he described seek the specific tarantula, go into its hole and after inspecting it thoroughly make sure it's the right kind of spider, digs a hole (grave) while the spider stands nearby watching, and then seeks the soft spot where her leg joins her abdomen to pierce it with its stinger. Once it succeeds and the poison renders it immobile, the digger wasp drags it to the grave hole, lays one of her eggs and attaches it to the spider with a sticky secretion and then covers it up and tramples the ground to keep out prowlers. Other species – like our tarantula hawk wasps – only seek the spiders to eat them.

The digger wasp's eggs hatch, the larvae live off the spider (which is not dead, but immobile) until all that remains is the skeletal remains, and the wasp's descendant gets safely started in life.

As kids, we had no idea of the natural relationship between the chupahuesos and tarantulas or what tarantula species they were. We though it was great sport to watch the little wasp go against the big spider. In our ignorance, we made them fight, unaware that we were merely mimicking a relationship going back into the mists of millenia.

(Ed.'s Note: After this story first appeared, we were told by people who know that "The gorgeous wasp on the picture is not a "digger wasp", it is a "tarantula hawk wasp", the difference being is that Diggers are yellow and black, wings transparent and stout legs (for an insect) while Tarantula Hawks are amber winged, black/blue and strong spindly legs that can pull the bigger tarantulas alive into their grave." Thanks for the lesson, guys.)