394 ENTOMOLOGICAL NEWS [Nov., '13 



minutely. Then she stood stock still at the entrance of the 

 cell for nearly a minute before she would again enter it ; then 

 after examining the interior and the opening for five minutes 

 more she flew away. 



Since this mother Pelopoeus was so keen in recognizing 

 spiders not of her own capture, an effort was made to de- 

 termine whether she would recognize and remove an intruding 

 larva of her own species if it were placed in her cell. Forth- 

 with a five-day-old larva from another nest was placed in the 

 cell, very near to the entrance. Now the wasps of this species 

 never see any more than the egg of their young, since the 

 egg does not hatch until after the nest is sealed. There is a 

 vast difference between the egg of this wasp and a five-day 

 larva, — such a difference that one would expect it to be taken 

 for an enemy and removed at once. 



The wasp returned, deposited the spider which she carried 

 and flew away in the usual manner, paying no attention to the 

 larva, even though she had to walk over it to deposit her 

 load. 



Shades of Moses ! Good, healthy spiders that would have 

 served as food for her young she removed just because she 

 had no voice in the matter of their selection, and now she 

 goes on supplying food for another mother's child, while her 

 own will inevitably be starved, if not devoured, by this im- 

 postor ! 



I left the nest at 5 o'clock, and at 6 the next morning found 

 that this cell had been sealed. I opened it and found that it 

 contained 14 spiders. To the abdomen of one of these ad- 

 hered her own larva, now 5 mm. in length. In addition to 

 these, there was the large larva which we had placed there 

 the day before, now almost a half inch in length and very 

 fat. The wasp had the fourth cell half done when this, the 

 third, was broken into during her absence, but she made no 

 attempt to repair the broken cell. It seems that after a cell 

 has once been sealed the interest therein is lost. 



We remember the attitude of this insect toward the spiders 

 taken from another wasp's nest and placed in her own. Now 



