CHAPTER XXVIII 



THE WHITE-FOOTED WASP 



Tryppxylon lencotrichium Rohmer 



An alert business-like insect, deep steel blue with a 

 white band encircling each of her hind tarsi, the white- footed 

 wasp is readily recognized. She inhabits the hot open trails 

 where bamboo grass has been slashed in clearing, leaving 

 here and there a severed hollow stem hanging in mid-air and 

 supported by the plant's shriveled leaves which catch among 

 other foliage. These hollow tubes supply the insect's favor- 

 ite nesting sites, unapproachable from below except by 

 winged enemies. 



The reed which the wasp had chosen had been severed 

 by a knife slash so that its end was sliced off at a gentle angle. 

 It hung four feet above the ground in a heavy patch of bam- 

 boo grass with its open end pointing toward the earth. Sev- 

 eral other open reeds of the same character surrounded it, 

 appearing to me very much the same. Not so to the wasp, 

 however, she differentiated at once and upon returning from 

 her journeys, flew directly to the reed of her choice. There 

 was no uncertainty in her approach, no repeated trials to 

 find the proper entrance. A straight, single flight from the 

 outer world to her tube marked her arrival. What a con- 

 trast to the clumsy one-banded dauber who wastes her pre- 

 cious time! 



I first found the white- footed wasp gathering a ball of 

 soggy clay in a pitfall trap in the trail leading to the forest. 

 Several of these holes had been excavated and for their in- 

 tended purpose of catching frogs, toads and the smaller ro- 

 dents they were perhaps less productive than they were of 

 wasps. The pits, after a rainfall, often contained several 



