Of Spiders and Hawks

By Eilene Lyon

Note: Just before Christmas 2024, I encountered a male tarantula roaming our neighborhood. In Southwestern Colorado, October is the month we usually see tarantulas crossing the road. Why? Read on…

Our local tarantula species (Aphonopelma vogelae), considered a “mini-tarantula,” is an unintimidating creature. They seem oblivious to the presence of humans and dogs. You must bluntly interfere with their ambling to get even a mild reaction. Stings or bites are unlikely. A tarantula can use its mandibles to procure food with a venomous bite. Or it can deflect potential threats with irritating hairs on the end of its abdomen. I’m neither food nor foe.

Females do not venture beyond the immediate vicinity of their burrows, from which they emerge at dusk to hunt. Unlike some spiders and insects, Ms. Tarantula is not inclined to eat her mate. Still, Mr. T makes his approach with caution. He strokes her and offers her sperm pouches to fertilize her eggs.

One researcher, observing mating behavior in captivity, remarked, “Frequently when the male has just touched the female with one of his front legs, and she does not show any visible response, he will slap her vigorously several times, which brings prompt action.” If I suitor tried this on me…well, let’s say there may be something to an arachnid’s cannibalistic post-coital behavior.

She waits until early summer to lay her eggs in a silk sack, stashing it in her burrow where the eggs gestate for 50–60 days. The young spiders do not venture far from the mother’s burrow before creating their own. It may take up to a decade for them to reach maturity (probably less for our local species, maybe eight years).

A. vogelae males, like all tarantula species, once they have completed their one-time mating mission, will weaken and typically die from cold weather or senescence, usually by late November. Some tarantulas in captivity have been known to extend their short span of maturity to the following summer, but this is not the norm. Females, on the other hand, may live another decade after maturing, producing offspring with a succession of doomed mates.

The male spider I encountered in late December was unusually long-lived. A retired biology professor told me, after I reported my find, “I think seeing tarantulas means good luck.” Lucky for him, perhaps, on this snowless winter day.

He is fortunate in a number of respects. He’s reached maturity without being eaten by a bird or lizard, or worse (I’ll get to that). He’s outlived his peers, has the chance to enjoy our relatively balmy winter, and probably passed on his genetic code. Maybe those genes will allow his male offspring to survive past their usual best-by date, making these spiders winners in a climate-changing world.

His most dreadful enemy—the tarantula hawk—is nowhere to be found this time of year. The tarantula hawk (Pepsis or Hemipepsis spp.) is no bird. It is actually a wasp in the Pompilidae family, up to two inches long, gun-metal blue with bright orange wings. We see them flying around in the summer months, conspicuous by their size and coloration. The adult wasps are nectivorous, but the females are seeking more than just a sweet sip.

A major reason that tarantulas remain in burrows during the day is to avoid these wasps. Much as the prairie dog fears the red-tailed hawk, the spider fears the spider hawk. The arachnids wish to avert a fate worse than being eaten by a bird or lizard or fox. The tarantula hawk is seeking hosts for her larvae.

If she lucks into finding a spider outside its burrow, she will paralyze it with her powerful venom, then lay an egg on her victim, depositing it back in its burrow. After hatching, the larva will devour the still-living tarantula. Yes, just like the creatures in the movie “Alien.” The spider will defend itself, but invariably in vain. Where is Ripley when you need her?

An unfortunate human or other mammal may discover that these wasps have a wicked sting—the most painful of any insect—something I hope never to experience. Fortunately, it lasts little more than a few minutes, whereas the similarly excruciating bullet ant sting can last 12 hours or more. Not surprisingly, the people most likely to be stung are those who research these beastly critters. Capturing them for study is not for the faint-of-heart.

One such scientist, the late Justin O. Schmidt, stated that a hawk wasp sting “typically resulted in the stung person uttering an expletive, tossing the net into the air and screaming—such was the immediate pain. To [me], the pain was instantaneous, electrifying, excruciating, and totally debilitating.” He recommends collapsing on the ground and screaming loudly with full abandon. Attempts to do otherwise would likely result in causing more accidental harm to oneself.

I can think of many situations where this advice might be useful: your dog dies, you get fired from your dream job, your best friend gives you the brush off, you perform a spectacular endo from your new mountain bike. The cathartic rolling around and wailing results in “leaving the person emotionally and physically drained,” per Schmidt’s account. Sounds like a great way to hit the reset button.

Though tarantula hawk venom causes no lasting harm to vertebrates, the pain it inflicts has effectively eliminated predation. These wasps have no fear of being eaten or attacked themselves. As a result, they live long and their offspring prosper. Their distinct coloration provides protection to other insects that benefit from mimicry.

When we think of predators and top-of-the-food-chain animals (aside from humans), what comes to mind are lions, grizzlies, and white sharks. But even these magnificent and fearsome fauna can’t hold a candle to the successful life of the spider hawk wasp.

Feature image: A typical October scene, when the male tarantulas are out “looking for love.”

Sources:

Baerg, W. J. “The Life Cycle and Mating Habits of the Male Tarantula.” The Quarterly Review of Biology 3, no. 1 (1928): 109–16. http://www.jstor.org/stable/2808188 .

Schmidt, Justin O. “Venom and the Good Life in Tarantula Hawks (Hymenoptera: Pompilidae): How to Eat, Not Be Eaten, and Live Long.” Journal of the Kansas Entomological Society 77, no. 4 (2004): 402–13. http://www.jstor.org/stable/25086231