KANSAS UNIVERSITY SCIENCE BULLETIN. 



twenty-one inches. The great colony in the cliffs in Ness 

 county was made up of many small colonies of twenty to thirty 

 nests, while spaces between these colonies, which offered situ- 

 ations for nesting of essentially the same character, were 

 untenanted. 



I could not observe any advantage gained by this colonial 

 habit. However, the wasps must have been influenced by each 

 other, for there was a tendency in a colony for all to do the 

 same kind of work at the same time. When I saw one wasp 

 bring a caterpillar to her nest I knew that the rest of the 

 colony was probably also on a hunt. When I saw one wasp 

 back out of her tube with a pellet of earth I expected to see 

 others also, either excavating or otherwise engaged in nest- 

 building. 



The time of day also seemed to be a dividing factor in the 

 kind of work 0. papagorutn would do. Mornings were gener- 

 ally spent hunting and storing caterpillars. Afternoons were 

 generally given to nest-building. 



0. papagoriim began working between 7:30 and 8 a.m. 

 during my stay in Ness county. She began hunting at once in 

 earnest, in contrast to some other Odyneri who would work 

 only in a desultory way until the morning was half gone. Late 

 in the afternoon some of these wasps would quit working. 

 Others I noted were still busy just before sunset. The night 

 was spent in the nest. 



During the busy season these wasps must make many trips 

 a day for water. Their familiarity with water does not make 

 them incautious about approaching it. Sometimes they will 

 alight upon still water, in tanks, pools, or in tracks beside 

 streams, but I have never seen them alight upon running 

 water, or even float upon it. When taking water from streams 

 they alight at the water's edge. Often they will take water 

 from the wet sand at the edge of a stream. 



When O. papagoriim aliglits on water or on the side of a 

 cliff, or when hunting on a flower head, it always keeps it? 

 wings spread and held up obliquely from the thorax, thus con- 

 stantly keeping them in a position to take flight at any time. 

 This is characteristic of all the Odyneri that I have observed. 



On their homecomings these wasps always, if undisturbed, 

 flew directly to their tubes, paying no attention to the tubes 

 of others in the colony. Was this due to a sense of direction or 

 to a memory of the nest's surroundings? I had noted a wasp 



