Proceedings of 

 the United States 

 National Museum 



SMITHSONIAN INSTITUTION • WASHINGTON, D.C. 



Number 3430 I960 Volume 111, Pages 337-680 



CYDNIDAE OF THE WESTERN HEMISPHERE 



By Richard C. Froeschner ' 



Introduction 



The group of hemipterous insects treated here as a full family, the 

 Cydnidae, exhibits definite pentatomoid aflSnities, even though a few 

 of the genera possess only four segments in their antennae. This 

 relationship has long been recognized and acknowledged, but the 

 features separating the cydnids from the other pentatomoids have been 

 accorded varying importance by different authors. Some workers 

 contend that the pentatomoids comprise a single family with many 

 subfamilies, thus according the cydnids subfamily rank under the 

 Pentatomidae; others express the belief that the present group and 

 the corimelaenid bugs deserve to be united into a single family, the 

 Cydnidae or Corimelaenidae according to the authority accepted, 

 while still others contend that even this arrangement is unsatisfactory 

 and that each of these two groups are properly given full family 

 status. 



A clear-cut definition of the Cydnidae in the restricted sense, as now 

 generally accepted and used here, is not easy to formulate. McAtee 

 and Malloch (1931, p. 194) listed several features which they con- 



1 Department of Zoology and Entomology, Montana State College, Bozeman, Mont. 



337 



