AN ISLAND SETTLEMENT 



to their attacks. Of the ten or twelve nests that we 

 opened only one was free from them, the others con- 

 taining from two to five lively maggots nearly as large 

 as the wasp larvae, which were sharing the food brought 

 in by the mother. Fabre, who has studied the question 

 thoroughly, has found as many as ten parasitic larvae in 

 one nest. He has also noticed that where the parasites 

 are most numerous the wasp-larva is proportionately 

 small and emaciated, reaching only one half or one third 

 of its normal size. When it attempts to spin its cocoon 

 it has not strength enough to do so, and thus perishes 

 miserably among the pupae of the interlopers, which have 

 the advantage of developing more rapidly. He has proved, 

 by experiments upon nests transported to his study, that 

 although the invaders preserve friendly relations with 

 the rightful owner of the nest so long as food is abun- 

 dant, they nevertheless, at the first suggestion of scarcity, 

 fall upon the wasp larva and ruthlessly devour it. This 

 'black action" he has seen with his own eyes. In view 

 of this base ingratitude, we are more than ever impressed 

 with the troubles of the poor Bembex mother, as she 

 tries to feed a dozen mouths where she has bargained for 

 only one. 



We several times saw a fly follow a wasp into her nest, 

 remaining within for half a minute, and it is probable 



133 



