22 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loe 



In the course of tliis study, the types of nine species {Rivellia 

 melliginis, R. brevifascmta, R. cognata, R. micans, R. floridana, R. 

 variabilis, R. 'pallida, R. flavimana, and R. severini) and a total of 

 approximately 3,500 specimens were examined. I am unable to 

 recognize R. atriventris Hendel.^ 



Very little is known of the biology of this genus. Fitch (1885) 

 recorded his observations of the activities of the adults of R. melliginis 

 on apple trees. Piersol's (1907) paper is the only other published 

 biological note that has appeared. Herein are recorded biological notes 

 on six species: Rivellia favimana, R. metallica, R. melliginis, R. 

 coguilletti, R. pallida, and R. ■urinifredae. These notes will be found in 

 the discussions of the respective species. 



The readily discernible differences between the male aedeagi of 

 most of the species offer good characters for the identification of 

 species in this group. In most specimens the aedeagus is retracted 

 and thus concealed within the abdomen. To expose the aedeagus, 

 which is located terminally on the long phallotheca, it is first necessary 

 to relax a dried specimen for a day. The phallotheca is usually looped 

 beneath the fifth tergite on the right side of the abdomen. By using a 

 No. 00 insect pin, which is hooked at the tip, the phallotheca can be 

 pulled out from beneath the tergite. Further pulling of the phallotheca 

 will expose the aedeagus. Sometimes the phallotheca will break before 

 the aedeagus is exposed, in which case the tip of the abdomen is cut 

 off at about the middle of the fourth segment with a pah' of fine scissors. 

 The severed part is then boiled or soaked in 10 percent KOH to get 

 rid of noncuticular material which obscures the aedeagus. In fresh 

 material the aedeagus should be exserted before flexibility is lost. 



I am deeply indebted to Dr. C. E. Mickel and Dr. E. F. Cook of 

 the Department of Entomology and Economic Zoology at the Uni- 

 versity of Minnesota for advice throughout this work. For the gen- 

 erous loan of material I wish to thank Dr. E. A. Chapin, who was 

 curator of insects at the U. S. National Museum at the time this 

 study was made, Mr. C. F. W. Muesebeck of the Section of Insect 

 Identification and Parasite Introduction, Entomology Research 

 Branch, U. S. Department of Agriculture, Mr. J. A. G. Rehn of the 

 Academy of Natural Sciences of Philadelphia, Dr. C. H. Curran of 

 the American Museum of Natural History, Mr. G. E. Shewell of the 

 Canadian National Collection, Prof. H. J. Reinhard of the Agricultm-al 

 and Mechanical College of Texas, Dr. J. L. Laffoon of Iowa State 

 College, Dr. D. L. Wray of the North Carolina Department of Agri- 

 culture, Dr. H. Dietrich of Cornell University, Dr. G. F. Knowlton 



> The combination of "rotgelbe" thorax, "Derobere Hinterkopf ist seitllch etwas blau," "Der Hlnterlelb ist 

 ganz unci gar metalllsch blauschwarz, glftnzend," and "die Kostalzelle hyalln" Is not present In any of the 

 species available. 



