David Power, age 12, of Dallas, Tex., for his question:
Is it true that the tarantula is not an insect?
This fellow looks for all the world like a furry, long fingered glove belonging to some native of the frozen north. But he lives in our warm deserts, and his cousins live in still hotter regions south of the border. The scientific name of our most common tarantula is eurypelma californicum, and the furry fellow is classified as a spider.
A typical insect has a waist, six jointed legs and a neck. A typical spider has a waist, eight jointed legs and no neck. The insects outnumber all the other animals on Earth, and the spiders belong in the second largest group. So far scientists have identified about 29,000 members of this group, and some of them are tarantulas.
It was not easy to arrange the large army of spiders in their proper places. Experts are still unsure where some of them belong, and the classifications sometimes differ. But all experts agree that the tarantulas are spiders and that spiders are not insects.
The animal kingdom, of course, includes all the animals from the whopping whale down to the one ce11ed amoeba. The pedigree of the tarantula begins in the animal kingdom. This vast horde is subdivided into phyla, and the next step of classification places our big hairy spider in the phylum arthropoda, meaning the animals with jointed feet. Insects and spiders, crabs and crayfish, barnacles and some 700,000 other creatures are arthropods.
The great phylum is subdivided into a number of classes, and at this stage the Insects and spiders are separated. Insects belong in the class insecta. The spiders, the scorpions and a host of mites and ticks belong in the class arachnida. The Arachnids are divided into a number of orders, and at this stage of classification the Spiders are separated from all the other animals in the animal kingdom.
All the spiders and only the spiders are classified in the order Araneae. The order is subdivided into families, and each family is subdivided into genera, which is the plural of genus. A genus includes just a few closely related spiders, and each individual spider belongs to a species of spiders exactly like himself.
The tarantula cousins that enjoy life in our deserts, in central and south america belong in two different families and several genera. Eurypelma californicum,~the scientific name of our most common tarantula, gives first his genus, spelled with a capital letter, then his species, spelled with a small letter.
Tarantulas include the largest spiders in the world, and one of the south american cousins is eight inches wide. Another wears rich purple brown fur, and his jointed legs are banded with circles of red and yellow. The common tarantula of north america is clothed in rusty brown hair. His body is two inches long, and his width, from tip to tip of his hairy toes, is about five inches.