ISELY: EUMENU)^ OF KANSAS. 303 



with caterpillars, which suggests that the egg could scarcely 

 have been suspended above them. Mr. Hartman's experiment 

 with the egg of 0. arrenftis showed that being among a number 

 of very lively caterpillars did not injure the egg or the young 

 wasp larvae, at least in that instance. 



The arrangement of caterpillars, as in the nest of 0. reni- 

 formis which Fabre described, so that the wasp larvje could 

 eat caterpillars in the order in which they were stored, can 

 scarcely apply to many species of Odynerus. In all of the 

 nests that I observed the caterpillars were not stored so that 

 the wasp larvae would be able to select them in the order in 

 which they were stored. With some wasps that stored their 

 cells within one or two hours, the order of storing could have 

 made little difference in the relative strength of the different 

 caterpillars. 



I collected some data on the observing ability of four eumin- 

 ids. This evidence is not sufficient to base any conclusions 

 upon, and a part of it is contradictory. 



O. papagoimn, O. arvensis and O. dorsalis all made locality 

 studies before beginning work on a burrow. This one locality 

 study before the beginning of work was the only one I ever 

 observed any of these wasps make, if undisturbed. They al- 

 ways flew directly to the burrow, because, I had supposed, they 

 had an accurate memory of their immediate surroundings. 

 0. amiulatus frequently made a short locality study before 

 alighting at her burrow. 



When I put sunflowers in the midst of a colony of O. papa- 

 gorum, mutilated a number of nests in another colony, and 

 disfigured the face of the cliff for several inches around the 

 colony, none of the owners of nests seemed to be disturbed, and 

 at first only one wasp seemed to even notice the change. They 

 flew as directly to their nests as before. If these wasps had 

 any observational ability at all, why were they not alarmed by 

 the depredations about their nests? How did they know that 

 those nests that they entered so confidently were their own? 

 Could they have been guided by a sense of direction and not 

 by memory of the surroundings of their nests? 



0. dorsalis usually noticed a few marks about her nest, but 

 only once did she seem to resent changes for any length of 

 time. In this instance I had cut away a part of the entrance 

 to her burrow, and she deserted it. The same was true of this 



6-Univ. Sci. Bull.. Vol. VIII. No. 7. 



