Isely: Nesting of Polistes. 343 



of appearance of the first sexually mature females was not noted. 

 The males did not go afield with the regularity of the females, but 

 spent most of their time on the nest, so that they made up the 

 greater proportion of wasps on the nest during the day. These 

 males were apparently waiting on the nest for the emergence of 

 sexually developed females. What was probably a preliminary to 

 mating was observed twice. As a female wasp was emerging from 

 her cell she was pounced on by a male and then by all the males on 

 the nest. This mass of wasps fell in a ball to the ground. When 

 disturbed by the writer, they separated. Mating was not observed. 

 A similar performance was noted at another nest later in the month. 



Observations were not made regularly after this time, the writer 

 having left Bentonville, but by the middle of October all males had 

 left the nest. A large number of females still collected there, but all 

 the brood had emerged and all activity had ceased. 



Considerable opportunity was offered to observe the workings of 

 the sense of direction, or rather the apparent lack of any such sense. 

 When the colony consisted of only a few individuals all of the wasps 

 apparently depended on local observations for finding their way to 

 their nest. Any change in the insectary shutters was confusing to 

 them. The oldest of the workers, when returning from the field, was 

 observed to alight on the shutter about a foot below and two feet to 

 the north of the nest. She would run on a horizontal line below the 

 nest and continue until she was about six inches past it, when she 

 would turn at a sharp angle and go directly to the nest. This path 

 was always followed unless the shutter was tampered with, when 

 the wasp could scarcely find the nest at all. None of the other 

 wasps followed this same path, but each apparently had its own 

 system. 



The overwintering queens of Polistes are sometimes gregarious, a 

 number of them starting a colony together in the spring. I have 

 never observed them working together in building an absolutely 

 new nest, but on several occasions I have seen a small number — 

 never more than seven — of overwintering queens renovate a large 

 nest left from the season before and start a colony together. This 

 probably accounts for the very large nests of several hundred cells 

 that frequently are found. These exceedingly' numerous colonies 

 were much more pugnacious than the small colonies. In fact, colo- 

 nies of but a few wasps are inclined to be shy rather than pugna- 

 cious. 



