TARANTULAS (September 95)

by Michael Ellis

I witnessed a most remarkable sight last Sunday on the slopes of Mt. Diablo — the mass movement of tarantulas. I must have seen 25 of these giant arachnids walking around and I escorted a number of them safely across the road. Every fall the males leave the protection of their burrows and search for females. I had always heard of this phenomenon occurring in the inner coast ranges, in Southern California and in desert regions but I had never actually seen it. In fact until last weekend I had only seen tarantulas in South America. These spiders are big; I was impressed.

Technically the California spiders are not true tarantulas. The original Lycosa tarantula is found only in Europe and is a member of the wolf spider group. Tarantulas take their name from the small Italian town of Taranto, where they were once numerous. Here the people believed that the bite of the tarantula was fatal. Just preceding death the victim entered a state of melancholy called tarantism. In order to survive death you had to listen to music during this tarantism. Not just any music, but the right music, which varied according to the particular whims of the victim.

The doctor would lead the patient, who was dressed in flowing robes, into a room where an orchestra was assembled. The doctor would then take the musicians through a few numbers. The patient would be unmoved until the right tune was struck. With a wild look in the eye, he’d get up and begin an uncontrolled frenzy, leaping about, flailing his arms and shrieking (I have seen similar behavior at a Grateful Dead concert). Finally dripping with sweat he’d drop, totally exhausted, but completely cured. I can just imagine the scene at the emergency room at Kaiser….” I just got bit by a spider. Is the orchestra in and do they know anything by The Moody Blues?”

The patient would have recovered anyway. Tarantula bites are not fatal; in fact it’s pretty hard to get one to bite you. But it was probably a good opportunity to act out some fantasies.

There are 15 or so species of “tarantulas” in California, which belong to a family called the Mygalomorphs. These are considered relatively primitive spiders because they do not spin webs, their mouthparts operate in a vertical fashion and they have four lungs. More advanced spider groups spin webs, have mouthparts that pinch and have two lungs.

All the tarantulas I saw were males. They are easily identified by the presence of giant pedipalps. These are large leg-like appendages near the mouth. In the fall a male constructs a sperm web where he deposits some seminal fluid. He then takes up a little of that sperm into special reservoirs on the tips of his pedipalps. Now he is ready to roll. Normally these spiders are nocturnal but during the breeding season the males are out night and day cruising for females.

When he finds a female burrow he taps the entrance with his legs and entices her to emerge. This is a dangerous operation. Tarantulas have been known to kill and eat animals much larger than themselves including small rodents, lizards, a small rattlesnake and even other tarantulas. The female may charge him with her fangs exposed. He grabs her fangs with special spurs on the inside of his front legs. He then flips her on her back and rhythmically uses his pedipalps to brush past her sternum. (Are you beginning to breathe hard here?). He places his packet of sperm in her genital pore and makes a hasty retreat; he doesn’t want to get eaten. In humans mating occasionally follows dinner, in spiders dinner occasionally follows mating.

The male tarantula will soon die; his job is done. Females on the other hand have been known to live over 20 years! Soon she will plug her burrow and spend the winter safe and secure far underground. Deep in her lair the following spring she will spin a thick egg sac and deposit 500 to 1000 eggs in it. The spiderlings hatch in about a month; the mother tears a small hole in the sac for her babies to emerge. They hang out with her for awhile before leaving the burrow. And the cycle for another amazing animal begins anew.



Posted on

August 4, 2009