1 903 Fossorial Hymenoptera 3 1 



beetles, flies, and other insects, which I feel convinced had 

 died of heat apoplexy. Indeed I very frequently kill my 

 specimens for collections by placing them in the sun for 

 a few seconds in small glass tubes tightly corked. 



On the commons in south-west Surrey occurs another 

 Pompilid, P. viaticus, a very handsome black-and-red insect 

 about Y\ inch long. This species provisions its nest with a 

 large brown spider, Lycosa terricola, which weighs about four 

 times as much as its persecutor, and is of proportionately 

 greater width. P. viaticus, working in firmer soil than 

 P. plutnbens, quickly excavates a burrow with her strong 

 jaws and legs, and uses the large coxal joints of the legs as 

 shovels to pass the loosened earth backward, or frequently to 

 drag it out as she herself backs out of the burrow in the 

 course of its formation. I strongly suspect this to be the 

 use of the enlarged coxae of all the Pompilids, but have only 

 actually observed that it is so in P. viaticus. The captured 

 spider is not dragged along over the ground, but is carried 

 along in the heather, and left suspended on a heather twig 

 during the frequent and often prolonged rests. Eventually, 

 of course, it must be carried over the ground ; but as the 

 burrows are generally made in small patches of sand, not 

 more than a foot or so in diameter, among the heather, the 

 distance so traversed is never great. I believe the reason 

 of this to be that the ground is generally teeming with ants 

 of various species, who soon would, and often do, make 

 short work of any helpless spider that they may find left 

 about. The burrow is made of such a width as to just 

 admit the fat body of the spider, which fits it like a plug. 

 When all is over the Pompilid most carefully fills in the 

 burrow and smooths down the disturbed soil, and in one 

 case that I observed actually went to the length of gathering 

 dead heather-bells and strewing them in a neglige sort of 

 way over the surface, thereby most completely effacing 

 all traces of the deed that had been done. 



All Pompilids do not confine their attentions to a single 

 species of spider — it is possible that in other localities the 

 species above mentioned may be found stocking their larders 

 with spiders other than those named here. I have myself 

 found a small Pompilid of another genus, Salius parvulus, 



