Cockroaches, Locusts, Grasshoppers, and Crickets i 27 



and humid and the roach's table is well set with good things. Almost any 

 sort of dry organic matter suits their taste; bread, crackers, miscellaneous 

 cold-lunch delicacies, the paste of bookbindings and wall-paper, leather, 

 woolens, and even their own egg-cases and cast skins making up the dietary. 

 The fo'k'sel and galley of ships are the roaches' special joy; the hotels and 

 restaurants of tropic and subtropic lands house swarms of these bill-evading 

 guests. From Mazatlan, Mexico, a naturalist sent me quarts of large native 

 .\merican roaches {Periplaneta atnericana), which he readily scooped up 

 from his bedroom floor. Ships come into San Francisco from their long 

 half-year voyages around the Horn with the sailors wearing gloves on their 

 hands when asleep in their bunks in a desperate effort to save their finger- 

 nails from being gnawed off by the hordes of roaches which infest the 

 whole ship. A few of our species still live outside under stones and old 

 logs, but most of them have learned that an easier life awaits them in the 

 kitchen. 



The roaches compose the Orthopterous family Blattids, and are an 

 ancient and persistent insect group. In Carboniferous times, before flies, 

 butterflies, bees, and wasps had come into e.xistence, cockroaches were 

 the dominant insects. The body in all is flattened and slippery with the 

 legs adapted for quick running, so that the insects are well fitted to escape 

 safely into narrow cracks and crevices. The head is concealed from above 

 by the expanded shield-shaped dorsal wall of the prothorax (pronotum). 

 Wings are present in most species, the front pair 

 leathery and serving, when the wings are folded, to 

 cover and protect the larger, thin, membranous 

 hind pair. In some forms the females are wingless, 

 and the indoor habit may be held responsible for 



the lessened usefulness and resultant loss of the ^'C- i,S7- — Egg-case of 

 ~, ^, . c.. J r , ... 1 J cockroach. (Three times 



wmgs. The mouth-parts are fitted for bitmg hard natural size.) 



dry substances, the jaws being strong and toothed. 



The eggs are laid in small purse-like, horny, brown cases (Fig. 157), which 



are usually carried about by the female until the young are ready to issue. 



The young grow slowly, requiring probably about a )'ear, in most species, 



to become fully developed. From the beginning, the young can run about 



and take care of themselves, eating the same kind of food as the adults. 



They moult several times during growth, and at each moult the wing-pads 



are a little larger. 



There are four common species of cockroaches found in dwellings in this 



country, only one of which is native. This is the large American roach, 



Periplaneta americana, about i\ inches long (to tip of folded wings), light 



brown in color, and with the wings expanding nearly 3 inches. This species 



is abundant in the middle and western states, having gradually extended 



