106 HYMENOPTERA 



CHAP. 



It has been stated that this wasp does not paralyse its prey 

 by stinging, but substitutes a process of biting to prevent the 

 spider from hurting the larva that is to feed on it ; and Verhoeff 's 

 observations seem to show that the legs of the spider are broken 

 by some proceeding of the kind. The Agenia larva is of peculiar 

 shape, the head not being innexed, while the pleurae of each 

 segment, from the second onwards, are prominent, so as to give 

 the outline of the body a scalloped appearance. This larva is 

 much infested by an Ichneumon that devours, it appears, not 

 only the larva itself, but also the spider that was destined to be 

 food for the larva. Verhoeff seems to have found some evidence 

 that Pompilus sericeus may also be a parasite on the Agenia. 



The construction of earthenware cells, instead of the burrows 

 usual in Pompilidae, by the species of this genus is one of the 

 cases alluded to in our introductory remarks as to allied Fossores 

 exhibiting different habits. Mr. Pride has recently sent us from 

 Brazil similar earthen vessels constructed by some Pompilid. 



The habits of Pompilids of the genus Ceropales are analogous to 

 those of the parasitic bees. Perez has recently given us information 

 as to a very curious form of parasitism in this genus ; he says that 

 when a Pompilus has obtained a spider as provision for its young, 

 it is pursued by a Ceropales, which lays an egg un the spider, thus 

 as it were substituting in advance its own young for that of the 

 Pompilus. Information as to the subsequent course of events in 

 this case is not at present forthcoming. In another case a 

 Ceropales was observed to oviposit on the spider, not while this 

 is being carried in, but subsequently by entering the nest for the 

 purpose ; a habit quite similar to that of some parasitic bees. 

 Ferton has recently made the unexpected discovery that some 

 Pompilus act as robbers ; one individual taking away by force the 

 spider that another has captured and is carrying off. 



Lichtenstein described a Pompilid larva, that he afterwards 

 ascertained to be Calicurgus lii/nli nutus, as possessing the extra- 

 ordinary habit of feeding as an external parasite fixed to the 

 dorsal surface of a spider ; thus repeating, it would appear, the 

 liabits of some of the Ichnemonidae, though the perfect Insect 

 (Fig. 143) does not differ in structure from its congeners. 

 Emery has given an account of some Pompilids that do not 

 bury their prey, but after stinging it and depositing an egg, 

 simply leave the spider on the spot, 



