Vol. 31, pp. 61-64 June 29, 1918 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



OCCURRENCE OF A EUROPEAN SOLITARY BEE (AN 



DRENA WILKELLA KIRBY) IN THE EASTERN 



UNITED STATES. 



BY J. R. MALLOCH. 



I have always been particularly careful in my publications on 

 North American insects to guard against the danger of recording 

 any European species as occurring here without actual compari- 

 son of specimens eminating from the different continents. I 

 can not help but believe that some of my fellow entomologists 

 consider my attitude towards certain records of Diptera pertain- 

 ing to species supposed to occur here and in Europe to be rather 

 one of natural perversity than of caution, but I certainly feel 

 that a conservative attitude should be maintained in the matter 

 of widening the published range of species because of the con- 

 fusion an error in identification may create in future references 

 to such species even after the error has been rectified in print. 



When insects feed upon particular plants it frequently occurs 

 that in the transportation of their host plant the associated 

 insect species are carried from one part of the country to another 

 or from one country or continent to another, and the natural 

 distribution of the insects is thus, by artificial means, very mate- 

 rially enlarged. Scavenging species in various orders find in the 

 commercial vessel plying between ports in different parts of the 

 world a ready means of distribution, and many such insects are 

 of world-wide occurrence. 



We have in the past had statements of the occurrence of sev- 

 eral European species of Andrena in North America, but these 

 records were subsequently suppressed, and attributed to errors 

 in identification. That some European species of this genus 



is— Proc. Biol. Soc. Wash., Vol. 31, 1918. (61) 



