“What’s the largest underground-dwelling invertebrate in the Bay Area? How does it live?” Paul, Berkeley


Well Paul that has to be the tarantula. There are 15 or so species of “tarantulas” in California are in the genus Aphonopelma in a family called the Mygalomorphs. But our spiders are not true tarantulas. The original Lycosa tarantula is found only in Europe and is a member of the wolf spider group.

Every fall the male tarantulas leave the protection of their burrows and search for females. Males are easily identified by the presence of giant pedipalps – large leg-like appendages near the mouth. The 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, 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 some 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 a while before leaving the burrow. And the cycle for another amazing animal begins anew.

Tarantulas take their name from the small Italian town of Taranto, where they were once numerous. Here tpeople 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 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 used to see similar behavior at a Grateful Dead concert). Finally dripping with sweat he’d drop, totally exhausted, but completely cured. 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.

The best location to view this autumn phenomenon is the inner coast range mountains like Diablo and Hamilton. There is even a tarantula festival in Henry Coe State Park Coe Park on October 6. http://coepark.net/pineridgeassociation/component/eventlist/details/7-tarantula-barbeque
I am not sure which band is playing there however.



Posted on

January 4, 2013