234 Annals Entomological Society of America [Vol. IX, 



I watched for these old residents every day, but it was not 

 until a week later (the Hemiptera were by that time gone) that 

 one returned to the old home to spend the night, but if it had 

 been marked the paint had worn off. I did not want to frighten 

 it away by marking it. The next evening, July 28, I found 

 three wasps here, all unmarked, but they were more skeptical 

 than ever (as would be expected of first-nighters) . Every time 

 I approached them they flew away, but persistently returned. 

 I tried to find marks on them but could not; they may have 

 been my lost friends with their identification marks rubbed 

 away. I could not bring myself to annoy them with markings, 

 so I left them, hoping they would return with their friends the 

 following night, but they returned no more. 



Later in the season, October 7, I saw three wasps of this 

 species asleep out in the field. Here too they were in their 

 characteristic position, the body stretched out horizontally, the 

 mandibles encircling a twig and most of the legs hanging free 

 in the air while the others lightly rested, in a casual way, upon 

 the twigs beneath. Two were on sweet clover and one on 

 goldenrod. Others of both sexes were seen during the last half 

 of August, in the regular position upon erigeron or white snake- 

 root. One was found hanging vertically by the mandibles. 

 Their way of spreading out their legs in the air may be a form 

 of relaxation. 



Elis 5-cincta Fabr. [S. A. Rohwer]. 



These wasps are probably parasitic upon certain beetle 

 larvae; they build no nest, but sting their prey in its natural 

 habitat, deposit an egg thereon and leave it. 



On a hot day in July, 1912, we found at 4 p. m., hundreds of 

 Elis 5-cincta at rest on the partly submerged vegetation of a 

 temporary pond. When we neared them they all flew away but 

 eventually returned. The remarkable aspect of the affair was 

 that all of them were mal^s. We supposed that the excessive 

 heat of the day had driven the males to rest early, and that the 

 females would soon follow. No similar congregations were to 

 be found on the surrounding vegetation, although this field 

 abounded in both sexes of this species, and especially the females 

 were plentiful and at work on the white flowers of the melolotus 

 at the time that these males were at rest. 



