IO 



THE STUDY OF INSECTS 



Representatives of thirty families of spielers are found in the United 

 States but only a few common forms can be discussed here, those which 

 best illustrate the habits of these most interesting animals. The spiders 

 will, however, well repay one for further study of them. With the excep- 

 tion of the hour-glass spider, common in the South and the tarantulas 

 found in the Southwest, spiders are harmless creatures and as safe to 

 observe and handle as beetles or ants. 



Family AViculariid^; 

 The Tarantulas and the Trap-door Spiders 



Those who live in the warmer parts of our country know well the 

 large spiders commonly called tarantulas. These are the giants among 

 spiders, some of them being the largest known; but some species of this 

 family are not very large. They arc dark-colored, hairy spiders, and can 

 be distinguished from the other families mentioned here by the fact that 

 the cheliceree work up and down instead of sidewise. 



The members of this family have various habits. Some live in the 

 cracks of trees or under stones or rubbish on the ground or sometimes 

 in a simple cell dug in the earth and lined with a slight web of silk. 

 Others dig definite tunnels in the ground, line them with silk and in 

 many cases close the opening with a door or lid. Others spin webs 

 resembling those of the grass-spiders known as the funnel-web weavers. 



One of the best 

 known of the tarantulas 

 is Eurypehna hentzi. This 

 species occurs in the 

 southern and southwest- 

 ern states, and is one of 

 the largest of our spiders 

 (Fig. 23). Several 

 closely allied species are 



Fig. 23. - A Tarantula, Eurypdma hentzi. found in California. 



But the members of this family that have attracted most attention 

 on account of their habits are the trap-door spiders. These dig a tube 

 in the ground, as do many other members of this family; but thi s tube is 

 lined with a denser layer of silk, and is provided 

 with a hinged lid, which fits the opening of the 

 tube with wonderful accuracy (Fig. 24). The 

 spider hides in this nest when not seeking its 

 prey. Some species take the precaution to build 

 a branch to their nest, and to provide this 

 branch with a door. As this door forms a part 

 of one side of the main tube, it is not likely to 

 be observed by any creature which may find 

 its way past the first door of the nest. 



Several species of trap-door spiders occur in 

 the southern and southwestern states. The hab- 

 its of many of these spiders are not yet known. 

 They should be studied much more. 



Fir.. 24. — Entrance to tunnel of 

 trap-dooT spider. (From the Spider 

 Book, Doubleday, Page and Co.) 



