AN INVADEB 293 



Next season I try again. I have at my disposal two 

 other beds, which I have sown with the late haricot, the 

 red haricot ; partly for the use of the household, but 

 principally for the benefit of the weevil. Arranged in 

 convenient rows, the two crops will be ready, one in 

 August and one in September or later. 



With the red haricot I repeat the experiment already 

 essayed with the black haricot. On several occasions, in 

 suitable weather, I release large numbers of weevils from 

 my glass jars, the general headquarters of the tribe. On 

 each occasion the result is plainly negative. All through 

 the season, until both crops are exhausted, I repeat my 

 search almost daily; but I can never discover a single 

 pod infested, nor even a single weevil perching on leaf or 

 flower. 



Certainly the inspection has not been at fault. The 

 household is warned to respect certain rows of beans 

 which I have reserved for myself. It is also requested to 

 keep a look-out for eggs on all the pods gathered. I 

 myself examine with a magnifying-glass all the haricots 

 coming from my own or from neighbouring gardens 

 before handing them over to the housewife to be shelled. 

 All my trouble is wasted : there is not an egg to be seen. 



To these experiments in the open air I add others 

 performed under glass. I place, in some tall, narrow 

 bottles, fresh haricot pods hanging from their stems ; 

 some green, others mottled with crimson, and containing 

 seeds not far from mature. Each bottle is finally given 

 a population of weevils. This time I obtain some eggs, 

 but I am no further advanced ; they are laid on the sides 

 of the bottles, but not on the pods. Nevertheless, they 

 hatch. For a few days I see the j^rubs wandering about, 



