Halloween gross-out: wasp v. spider smackdown

Tarantula, Round Valley.

In the 1979 film “Alien,” a monster in hatchling form lays a parasitic larva inside one of the good guys. The larva matures in a couple hours and – no respecter of immaculate walls and ceilings – bursts through the host’s chest as a small (soon to grow really really large) beast with little or no sense of humor.

One factor that keeps our eyes riveted to the screen is the consolatory concept “it’s just a movie.” Just fiction. But where do these makers of horror fiction get some of their best ideas? From the facts.

Of the creatures we run across in real life, the spider ranks high on the creep-out quotient. A life form grotesquely unlike us, it sports eight legs and way too many eyes for our taste. It wears its skeleton on its sleeve and its abdomen in its back pocket. And it dines with a gruesome gentility, paralyzing its prey with venom, wrapping the hapless victim in silk while its innards liquefy, and returning later to sip away with a straw.

One creature that suffers from not a twinge of arachnophobia is the tarantula hawk (we’ll shorthand it as “T. hawk”), a large wasp that preys on tarantulas. As in “Alien,” the T. hawk delivers an especially nasty package to its victim. But the horror inflicted on the character Kane in “Alien” is a spa holiday compared to the real-life tarantula’s ordeal. Shall we elaborate?

The male tarantula stops growing at about age 7 and sheds his exoskeleton for the last time. Normally a nocturnal creature, the mature male leaves the protection of his burrow in September and October and goes searching for a mate in broad daylight. That procreative impulse is good for the species but hazardous to the suitor’s health. Out in the open, the tarantula is a prime target for the T. hawk.

The T. hawk measures up to 2 inches in length, making it one of the largest wasps in the world. It hunts the tarantula on the ground, by scent, skittering around till it finds the female spider’s burrow or locates the male spider while he’s out cruising for chicks.

A tarantula hawk sips nectar at Los Vaqueros. The wasp uses the spider not as food, but as a larva nursery.

The T. hawk probes the spider with its antennae, formulates a plan of attack and strikes with its stinger, which delivers a paralytic blow to the tarantula’s nervous system from which the spider never recovers.

A tarantula expelled from its burrow and paralyzed will be dragged back to the burrow; a tarantula ambushed in the open will be dragged to a burrow excavated by the T. hawk. The female wasp lays an egg on the spider’s abdomen and seals the crypt.

It takes about a week for the larva to hatch. Keep in mind that the spider isn’t dead; merely paralyzed. The T. hawk grub burrows into the spider’s abdomen and feeds – and here’s the icky part – bypassing the spider’s vital organs in order to keep it alive. Clever little grub. When dessert time comes and the spider’s vitals are finally devoured, the grub begins the pupation process, which takes a few weeks. The cute little T. hawk grub morphs into an adult, then re-enacts the “Alien” scene in a climactic belly burst.

A public-service announcement: the T. hawk’s sting is hazardous not only to the tarantula’s health; it can put the human nervous system on pain overload. Although the T. hawk isn’t easily provoked, its sting ranks among the most painful of any insect. According to biochemist Justin O. Schmidt, the T. hawk sting delivers “immediate, excruciating pain that simply shuts down one’s ability to do anything, except, perhaps, scream. Mental discipline simply does not work in these situations.” Outside Magazine’s Katie Arnold describes the sting as “blinding, fierce, shockingly electric. A running hair drier has been dropped into your bubble bath.” The good news: the peak pain lasts only three minutes and isn’t lethal.

In Round Valley's Murphy Meadow, a male tarantula inspects a burrow in hopes of hitting on some long-legged, eight-legged brunette.

The male tarantula leads a hard life. He must fend off not only the T. hawk, but the female tarantula during mating. A famished female will kill (though seldom eat) the male if he fails to make a swift and smooth exit from the coital scene. As a defense, the male grows two tibial spurs (“stirrups”) with which he hooks and neutralizes the female’s fangs before mating.

After luring the female out of her burrow and impregnating her, the male tarantula never returns to his own burrow. He puts his nose to the reproductive grindstone and continues pounding the pavement for poontang until the lethal winds of November – or a T. hawk – permanently ends his quest.

Tarantula mating season is nearly done. If you’re lucky enough to cross paths with these remarkable creatures, admire, take your snapshots, but cut them some slack. Unlike those cardboard creepy-crawlies infesting our haunted houses, they’re probably minding their own besotted business.

And if you hear a buzzing noise and spot a large, orange-winged, black-bodied wasp, follow the the tarantula’s inspiring example. Duck for cover.