AN INVADER 299 



the mothers sow their eggs at random ; the young larvae 

 establish themselves some in beans that are so far intact, 

 some in beans which are perforated but not yet ex- 

 hausted ; and all through the summer the operations of 

 breeding are repeated once in every five weeks. The 

 last generation of the year — that of September or 

 October — sleeps in its cells until the warm weather 

 returns. 



If the haricot pest were ever to threaten us seriously 

 it would not be very difficult to wage a war of extermina- 

 tion against it. Its habits teach us what tactics we ought 

 to follow. It exploits the dried and gathered crop in the 

 granary or the storehouse. If it is difficult to attack it in 

 the open it would also be useless. The greater part of 

 its affairs are managed elsewhere, in our storehouses. 

 The enemy establishes itself under our roof and is ready 

 to our hand. By means of insecticides defence should 

 be relatively easy. 



