Varieties of a Rose Gall Wasp (Cynipids, 

 Hymenoptera)' 



By Alfred C. Kinsey and Kenneth D. Ayres 



The following is a study of the varieties of Diplolepis 

 tuberculatrix (Cockerell), based largely on material collected 

 by the senior author during the spring of 1920, while he was 

 a Sheldon Travelling Fellow of Harvard University. We have 

 almost exactly four thousand insects of tiihercukitrix, and 

 some thousands of galls. In spite of which there remains 

 much work to be done, for we do not yet have material from 

 the majority of the more or less distinct faunal areas of the 

 parts of western United States probably covered by the 

 species. Many additional varieties should be disclosed. 



The merits of our conception of a single species with many 

 varieties are emphasized by the serious confusion in the 

 bibliographic synonomies of previously described forms. It 

 has never been possible to separate material by means of the 

 scanty descriptions available; always the descriptions ignored 

 the distinctive characters concerned. Considering that dis- 

 tinct species alone were the only concerns, some synonomy 

 was introduced for very similar material, making the utiliza- 

 tion of existing data more difficult. 



Each variety as far as known is confined to a faunal area 

 stamped as distinct by parallel distributions of other Cyni- 

 pidse, of other insects, and of plants to some degree. Within 

 each area individuals vary as do all individual objects, but 

 nevertheless are most remarkably uniform. The limits of the 

 range of each variety are not often crossed by other varieties ; 

 at the meeting points of two forms, the two remain distinct, 

 without the occurrence of the traditional intermediates. Wit- 

 ness xerophikt and wasatchensis. Geographic isolation is an 

 accom.paniment of the occurrence of distinct varieties in this 

 species, whether or not we care to consider it the cause. 



There can be no doubt of the specific unity of this group. 

 The females are separated on relatively few characters, the 

 males are still more difficult to distinguish, if indeed it can 



^Contributions from the Zoological Laboratories of Indiana University No. 194 (Entomological 

 No. 3). 



(142) 



