MINERS 29 



One of these spider-hunters is Calicurgus, but 

 although it belongs to the group of burrowing 

 Hymenoptera it mostly seeks for a ready-made hole 

 in which to deposit its prey and its eggs. The 

 Spider-wasp (Poinpilus) is a true miner, but it 

 reverses the order of operations followed by the 

 solitary bees we have mentioned. Instead of first 

 sinking a shaft and forming cells, and then seeking 

 for provisions for the future grub, Pomfilus first 

 captures its spider and then excavates a hole in 

 which to accommodate it. It is probable that this 

 plan may frequently lead to the nest being ready 

 first, owing to the first secured prey being carried 

 off by another wasp whilst the mining operations 

 are in progress. 



Fabre gives a detailed account of some experiments 

 he made in order to test Pu7nfilus'^ sense of locality, 

 and to ascertain how she would behave under certain 

 conditions. A Pompilus that he had watched catch 

 and sting a spider to render it helpless left her prey 

 on a tuft of vegetation whilst she proceeded to 

 make a burrow. She does not wait until the burrow 

 is finished before looking for the spider, but leaves 

 off work at intervals in order to visit the spider, 

 to touch it and so assure herself that it is her spider, 

 and that it is quite safe. In this case, as soon 

 as the wasp had set to work on her mining operations, 

 Fabre removed the spider to a distance of about 

 eighteen inches. When Poinpilus had worked for 

 a spell she left off and flew straight to the spot 

 where she had left her treasure, and exhibited grave 



