32 INSECT BEHAVIOR 



contains twenty spiders separated into three little groups by half 

 partitions of clay. Upon the abdomen of a large spider in each 

 group she has deposited an egg. Now I close the box and await her 

 return. She arrives laden with a tiny ball of clay in her mandibles, 

 enters the nest for a moment and then flies off minus her burden. 



At the end of an hour the operation has been repeated twenty 

 times. Now she commences to close the entrance with the same 

 material. The job requires ten more loads of mortar, but it is 

 completed rapidly. By evening she has left the nest, I presume 

 for good and all, and for the last time I pry into her secrets. 



It is all very clear. In a single day she has accumulated the 

 entire amount of provisions necessary to provide her three off- 

 spring, and separated them into distinct groups. Further she has 

 constructed half partitions that keep the stores separate, but still 

 permit her to pass from one end of the nest to the other. Thus she is 

 enabled to deposit her three eggs in different departments of the 

 nest, all on the same day. The laying over, she has only to finish 

 the half partitions with a few loads of clay, plug the entrance and 

 her work is completed. 



She deposited all her eggs within an hour and they are safe in 

 isolated cells. The three will pass through their metamorphosis or 

 life history, as one. They will eat and grow and pupate together, 

 and issue into the world almost at the same moment. Thus the black 

 reed-wasp solves the problem very simply. She brings her offspring 

 into the world as triplets! 



