Natural History Notes of Southern Arizona. 7 



The large species calk-tl Toad Orasshopper (Phyrnotetix 

 Magna) were common. July 14, many pairs taken in couple. 

 They varied much in color, and closely resembled the color 

 of the ground where they lived. Some specimens taken 

 among fragments of disintegrated, rust-colored rock were 

 colored just like the rock, so much so that it was impossible 

 to see them unless they moved. The female is huge in 

 size, the males much smaller. They can not fly, having the 

 wings aborted. This mimicry of color is doubtless a pro- 

 tection from the keen eyes of numerous mocking birds who 

 feed largely on grasshoppers. During July, many of the 

 Lociistidae and Acrididae are mature, though some species 

 are not until later. A few species were of very bright colors, 

 one kind found higher up in the canyons had beautiful blue 

 hind wings. A huge, long-winged grasshopper was powerful 

 in flight and difficult to catch. It is called Schistocera vaga. 

 Some of the round holes in the ground were occupied by 

 giant Tarantulas. One monster we dug out at a depth of 

 ten inches made a savage bite at the net handle, but, after 

 that gave up and died quickly in the cyanide jar. The 

 deadly foe of these huge spiders is a wasp called Tarantula 

 Hawk, belonging to the genus Pepsis. Some specimens 

 taken were two inches long, with a wing spread of three and 

 one-half inches. Their sting is most formidable, and des- 

 perate battles take place between them and these huge 

 spiders, and the wasp generally wins, though not always. 

 The object the wasp has in attacking the spider is to deposit 

 her egg on the body of the paralyzed spider, which serves 

 as food for her young. The spider evidently knows that 

 one thrust of the sting will be fatal, and makes a desperate 

 effort to escape. The peculiar jKiralyzing and preserving 

 effect of the virus of the wasp's sting is one of nature's 

 marvels, for if the sting killed the spider outright, its body 

 would decompose before the young wasp larva reached 

 maturity. Pouring water into the Tarantula's hole generally 

 brings them to the surface. In turning over logs, some 

 monster centipedes were uncovered. They are very striking 



