OBSERVATIONS ON THE BALL-ROLLING BEHAVIOR 
OF CANTHON PILULARIUS (L.) 
(COLEOPTERA, SCARABAEIDAE ) 
By Eric G. Matthews 1 
Department of Biology, University of Puerto Rico, Rio Piedras 
The present paper describes some aspects of the normal behavior 
of Canthon pilularius (L.) (C. laevis [Drury]) in the field and is 
the result of direct observations totalling about 57 hours, carried out 
in four field locations in Florida and Georgia in 1957 and 1961. 
The approach of this study is neither ethological nor ecological, but 
taxonomic. That is to say, certain aspects of the normal behavior of 
the scarab were investigated and quantified with a view to using 
them as taxonomic characters in comparison with other related species 
and genera. My data on other species of the genus Canthon are not 
yet complete enough to present an interspecific analysis of the behavior 
of this genus, but are adequate for an intergeneric comparison with 
European representatives of the ball-rolling genera Scarabaeus, Gym- 
nopleurus , and Sisyphus, which have been studied in detail by Ger- 
man investigators. Such a comparison is now in preparation by the 
author and will be published subsequently. 
Previous literature gives the outlines of the life history of C. 
pilularius (Lindquist, 1935; Cooper, 1938; Ritcher, 1945; Miller, 
1954), but there are no published observations describing the behavior 
sequences seen.. Brief notes on the biology of about 25 other species 
of Canthon, sensu stricto, have been recorded in the literature (see 
von Lengerken, 1954, Pereira and Martinez, 1956, and Halffter, 
1959, for discussions). 
This species is commonly known in the United States literature as 
Canthon laevis (Drury). However, it has been known for some time 
that this is not the correct name. In a recent revision of the genus 
(Halffter, 1961) there is a review of the reasons showing why the 
name pilularius Linnaeus, 1758, is most probably correctly attributed 
to this species. Furthermore, Lane (1950) shows that even the name 
hudsonias Forster, 1771, has precedence over laevis Drury, 1773. 
The present investigation was supported in part by Postdoctoral Research 
Fellowship No. 12,061 of the National Institute of Mental Health, N.I.H., 
U. S. Public Health Service, while the author was at the Biological Labora- 
tories, Harvard University. Publication of this work was aided by a grant 
from The Society of the Sigma Xi and RESA Research Fund. 
Manuscript received by the editor September 12, 1962. 
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