134 HOUSEHOLD INSECTS 



It is evident, then, that in the cases which have been 

 actually observed, the cockroach completed its growth in 

 much less time than has commonly been reported. Un- 

 doubtedly the time consumed in the development of young 

 cockroaches depends upon the temperature, amount of 

 food available, and other surrounding conditions. Perhaps 

 a scarcity of food, low temperature, and other unfavorable 

 conditions might combine to retard the development of 

 the nymphs and prolong it for years. 



DOMESTIC SPECIES OF COCKROACHES 



There are four principal species of cockroaches that 

 frequent dwellings, other buildings, and ships, and cause 

 the trouble that we have described in the foregoing pages. 



Probably the best known and most disliked of the four is 

 the German cockroach, or croton-bug, Ectobia germanica, 

 as it is known in this country (Plate II). This species, 

 so abundant in Germany and adjoining countries, is 

 now widely distributed all over the eastern and south- 

 ern parts of the United States and when it once enters 

 a house it increases so steadily that it becomes exceedingly 

 numerous. In a single fumigation of a small pantry and 

 kitchen, the writer has killed over a gallon of these 

 roaches by actual measure. Yet during the daytime they 

 were not in special evidence, but their trails, odor, and 

 general filth were everywhere and in everything. 



It is the smallest one of the domestic species and the 

 most difficult to get rid of or control. Moreover, it in- 

 creases faster than the others because it lays more eggs at 

 a time and the young complete their growth sooner than 

 those of the other species. It is light brown in color 



