306 THE WASPS. 



Markel, almost word for word. The caterpillar put in was 

 three times as large as the insect. The latter first pulled 

 away a little ball of earth with which it had covered the 

 opening of the hole, visited the interior, and then pulled in 

 the caterpillar. The hole was then filled up with little 

 stones and sand, and the earth smoothed over. At last the 

 insect put two small pointed leaves on the spot where the 

 opening had been, apparently, as the observer thought, so 

 as to recognise the place again!* The North American blue 

 sand wasp (Sphex or Ammophila c>/anea, Ichneumon ccerulea), 

 described by Bates, acts just in the same way as is related 

 by this writer of the Pelopceus fistularis. It builds cylin- 

 drical clay cells or clay tubes with divisions for its eggs, 

 and fills them with captured insects, such as spiders, as food 

 for the young when hatched. During building it emits a 

 peculiar singing note, which can be heard at ten yards 

 distance, and which seems to lighten its toil. It carries off 

 spiders as large as itself, and, when they are too heavy to 

 fly with, pulls them along the ground. Mr. jCatesby 

 weighed a wasp and a spider carried by it into the nest, 

 and found the weight of the latter to be eight times as 

 great as that of the former. 



The grasshoppers, which the Pennsylvanian sand wasp 

 (Ammophila or Sphex Pennsylvania) carries into its holes as 

 food for its young, are, as a rule, stronger and larger than 

 the robber, which falls upon them suddenly from behind 

 and disables them with its sting, so that they can make no 

 resistance. As already mentioned, all the butcher wasps treat 

 their prey in this fashion, and with the well-conceived 

 design of making them defenceless but of not killing them, 

 as they would otherwise soon decay in the nests and so be 

 useless for the proposed object. There are also some digging 

 wasps which, like Bembex, bring daily fresh nourishment to 

 their young. 



According to Taschenberg (in Brehm, loc. cit., ix., p. 277), 

 Gueinzius saw a butcher wasp (Pompilus Natalensis) which 

 followed a large female spider through the open door into 



* According to Taschenberg (Brehm, loc. cit., ix., p. 283,) the sand 

 wasp shuts off the entrance of its nest in a similar way, in order to 

 make it impossible for parasitic insects flying about to lay their eggs 

 therein. 



