COCKROACHES. 25 



are like the parent, but without wings, and are 

 white and limp. The outer skin hardens, and the 

 brown colour appears. In from nine to twelve 

 months the cockroach is grown up. During that 

 period it has moulted seven times, the increase in 

 size taking place at each moult. After the third 

 or fourth moult, the wings begin to show as tiny 

 pads, and at the seventh moult they are fully de- 

 veloped. 



Sometimes a much longer period than twelve 

 months elapses before the perfect state is reached, 

 but this depends much on the weather, and on the 

 food supply. The food of the cockroaches consists 

 of decayed animal and vegetable matter, paper, 

 paste, etc. In fact, they will eat almost anything, 

 and may be looked upon as scavengers. 



We sometimes become conscious that these crea- 

 tures have passed over food by the odour left be- 

 hind. This odour is due partly to a fluid coming 

 from the mouth, and partly from scent glands situ- 

 ated between the segments of the abdomen. 



Nature frequently provides her own remedies for 

 insect pests, and in this family the wasps are the 

 most to be feared. One wasp (Evania) is found 

 laying its eggs in the egg case of the Cockroach. 

 Man, however, has to resort to methods where re- 

 sults are more quickly seen. Borax sprinkled freely 

 in infested parts proves most effective. An in- 

 stance came under our notice in which an old stone 

 building with a stone floor was over-run with our 

 own smaller cockroach. Several pounds of borax were 

 used, being sprinkled freely in the cracks of the floor, 



