62 



ENTOMOLOGY. 



got of the flesh-fly, infest them, and thus thousands of them 

 are swept away. All this is of use, however, for were it 

 not for the kindly aid thus rendered, the earth would be 

 each year overrun with locusts. 



The males of many Orthoptera, as the crickets, green 

 grasshoppers, katydids, etc., and locusts, produce loud, 

 shrill sounds, by which they attract the females; but in the 

 European Ephippigera, one of the Locustidae, the female 

 is provided with well-developed vocal organs. They stridu- 

 late in three ways i.e., first, by rubbing the base of one 

 wing-cover on the other (crickets and green grasshoppers); 

 second, by rubbing the inner surface of the hind legs 

 against the outer surface of the front wings (some locusts); 

 third, by rubbing together the upper surface of the front 

 edge of the hind wings and the under surface of the wing- 

 covers during flight (some locusts). 



Family Blattariae. Body flattened, 

 oval, with a broad pronotum; fore 

 wings broad oval; antennae long and 

 filiform. Blatla orieutalis Linn., and 

 Periplaneta americana (Linn.). While 

 troublesome from eating clothing, 

 etc., and mischievous in bakeries and 

 storehouses, they are serviceable in 

 clearing houses and ships of bed- 

 bugs. The eggs are laid in a bean- 

 shaped capsule (ootheca), which is 

 divided into two compartments, each 

 * containing about thirty eggs. Our 



FIG. 46. Croton bug, Ectobia ger- native species, Plata-modes pensyl- 

 mnnica. Natural size. vanic-a (De Geer), lives under stones. 



All are nocturnal in their habits. The metamorphosis of B. orientals 

 is said to require four years. 



Family Mantidae. Fore legs adapted for seizing their prey, which 



FIG. 47. Mantis Carolina, soothsayer. Natural size, 

 consists of other insects. Eggs laid in large bunches on various plants. 



