190 THE SOLITARY WASPS. 



not too heavy for her to caiTj nor too big to be pushed into her 

 cell. We have not a spider in our fauna that would not fall a 

 speedy victim to our Pelopaeus should she attack it. When ex- 

 perimenting on the mating habits of Attidae, some yeai-s ago, 

 we kept large numbers alive in our mating-boxes, and we found 

 the females of Phicldipus tripunctatus so vicious and powerful 

 that they had to be kept in solitary confinement to prevent their 

 killing the other spiders, and yet our slender mud-daubers used 

 these very females, even when they were full-grown. The 

 small and feeble spiders then, are not taken because they are 

 small and feeble but because they are so very abundant as to 

 make them a convenient source to draw from. All spider col- 

 lectors know that for each adult specimen taken in collecting 

 there are at least twenty that are immature. Among certain 

 species it is almost impossible to get an adult specimen at certain 

 parts of the season although the immature forms are found on 

 every bush. In the latter part of August or early in Septem- 

 ber the female of A. riparia lays from five hundred to two 

 thousand eggs. The young spiders remain in the nest through 

 the winter, and in the following May begin to spin their little 

 webs everywhere. Through June and July the mud-wasps on 

 their hunting expeditions meet them freqr.ently and use them 

 freely. As they grow larger and sciircer other crops of young 

 and common spiders take their place. Interpolated all through 

 the season, we find the larger and rarer kinds in just about the 

 proportion that they bear to the smaller ones in nature. 



Fabre's chapt-er on "Les Vivres du Pelopee" bears so strongly 

 upon our subject and is so interesting in itself that it seems well 

 to repeat some parts of it here. He says that so far as discover- 

 ing the method of attack in Pelopaeus is concerned his efforts 

 have not been crowned with any great measure of success. He 

 has seen the wasp swoop down upon a spider, clasp it, and carry 

 it away, almost without pausing in her flight. Other hunters 

 alight on the ground, make their fastidious preparations sedate- 

 ly, and distribute the strokes of the sting with the calm deliber- 

 ation which a delicate operation demands. This one darts 

 down, seizes her victim and departs, something after the manner 



