COCKROACHES AND THEIR CONTROL 3 



The oriental cockroach (Blatta orientalis L.) (fig. 3), or " black 

 beetle"', is entirely black, or deep brownish black, attains a length of 

 about 1 h 4 inches, is the most sluggish in its movements, and thrives 

 best in very damp places. The female is almost wingless and cannot fly. 



The German cockroach (Blattella germanica L.) (fig. 4), "croton 

 bug", or "water bug", never more than five-eighths of an inch long, is 

 one of our smallest roaches. It is light brown and is marked on the 

 back between the head and wings with two dark parallel stripes. 

 The wings are of a uniform light-brown color. 



Figure 4.— The German cockroach: a, First stage; b, second stage; c, third stage; d, fourth stage; e, adult; 

 /, female with egg case; g, egg case (enlarged); h, adult with wings spread. All natural size except g. 



The tropical cockroach (Supella supellectilium Serv.) (fig. 5), a more 

 recent pest of cities in the Gulf coast region, is slightly smaller than 

 the German cockroach, many females being only three-eighths of an 

 inch long, whereas the males are about one-half inch long. The 

 females have bodies much broader than the males and wings that are 

 reddish brown ; the wings of the males are much lighter. Both sexes 

 are distinguished from the German cockroach by two cross bands of 

 light yellow, one at the base of the wings and the other about one- 

 sixteenth of an inch farther back. 



/ A 



Figure 5.— A tropical cockroach, Supella supeUectilium: A, female; B, male. Three times natural size. 



How Cockroaches Develop 



Cockroaches lay their eggs in leathery capsules, which the mother 

 roach carries for some days partly extruded from her body. She often 

 glues these capsules finally to some object, but sometimes merely drops 



