124 OUTLINES OF ENTOMOLOGY. 



insects revert more or less to this color, though soon becoming of the 

 shade of brown which characterizes them. 



Our native species seldom give us much annoyance. The males 

 occasionally fly into lighted rooms at night, but the females are usually 

 found around rotten stumps and under bark of dead trees. The Light 

 brown cockroach fPlatamodes Pennsylvania} is the largest species. It 

 measures about an inch in length, has very delicate wings, and is of a 

 light brown color. A smaller species of a very dark brown or black 

 color, but with lighter margins, is also quite common. This is Ectobia fla- 

 vocincta. The most destructive and annoying cockroaches are found 

 among the introduced species. These are especially, the large, very 

 dark brown or black Oriental cockroach (Periplancta orientalis, Linn.), a 

 species which is supposed to be native in eastern Asia, but which now 

 occurs in all parts of the civilized world. It is about one inch long and 

 one-third of an inch wide, very flat, so that it is able to creep into the 

 smallest crack. The wing covers in the male extend over little more than 

 one-half of the abdomen, and in the female are still more rudimentary 

 These insects are very long-lived, and it is said require several years 

 to complete their transformations. The smaller, German cockroach, 

 also called the "Croton bug" (Eotobia germanicaj, has become very 

 troublesome in the eastern cities, and from its fondness for wheat bread 

 and dough, is the especial pest of bakeries and bread boxes. This 

 species has fully developed wings, and is of a light brown color, with 

 two dark stripes on the pro-thorax. 



The free use of pyrethrum powder will preserve cloth-bound books 

 and similar property from the attacks of these insects, and if used 

 freely in kitchens and other places which they frequent, will render 

 them helpless, so that they may be easily swept up and^burned. Pow- 

 dered borax mixed with sugar will also kill them. 



