SARRACENIA VARIOLARIS. 199 



wasp building its nest within the fresh young leaves, 

 usually before the leaf has caught a single insect. The 

 nest is made of dry, fibrous material — probably stripped 

 from some dead herbaceous plant — and dry grass. This 

 material is crowded as low down in the tube as the 

 wasp can go, and it extends upward an inch or more. 

 On this bed is laid the food for the young wasp. The 

 food consists of five or six young grasshoppers, which 

 the parent wasp has stung and paralyzed in such a 

 manner that they are kept alive for the young wasp to 

 devour. The grasshoppers are covered with the same 

 material as that found in the bottom of the nest, to the 

 depth of about an inch, the material being wadded in 

 close and tight. I have also found the nest of a leaf- 

 cutter bee in the tube of Sarracenia. These nests I sent 

 to Professor C. V. Riley for identification. 



I give here Professor Riley's account of the nests, 

 and I also take this opportunity to acknowledge his 

 kindness in aiding me in various ways in my researches, 

 and especially in his excellent and very accurate draw- 

 ings of the chironomus and mosquito larvae on pages 

 142 and 143 : 



"The nest made of leaves belongs to a leaf -cutter 

 bee, genus Megachile. The species cannot, of course, 

 be determined except by breeding. These insects nor- 

 mally build their nests in burrows which they make in 

 the stems of soft pithy plants, like elder, and the appro- 

 priation of the Sarracenia .tube is very interesting. It 

 is very likely that this bee aids pollination of the flower, 



