PSYCHE 
Vol. 71 March, 1964 No. 1 
CHEMICAL RELEASERS OF SOCIAL BEHAVIOR. 
II. SOURCE AND SPECIFICITY OF THE ODOR 
TRAIL SUBSTANCES IN FOUR ATTINE GENERA. 
(HYMENOPTERA: FORMICIDAE) P 
By Murray S. Blum * 2 , John C. Moser 3 , and A. D. Cordero 4 
The higher members of the tribe Attini characteristically lay per- 
sistent and extensive odor trails especially in many neotropical areas. 
Thus, in Acromyrmex and Atta, long columns of foraging workers 
are frequently present on the odor trails but in the less specialized 
attine genera, workers may forage either in files or singly. Weber 
(1958) has indicated that the workers in monomorphic genera forage 
singly, a behavioral characteristic which he offers as evidence for 
the primitive position of these attine genera. 
Species in the genus Trachymyrmex appear to be intermediate, 
since they forage either singly or in columns. This, Weber concludes, 
indicates a transition to the well developed odor trails of the higher 
attines. 
Since the Attini constitute a tribe of closely related genera which 
exhibit varying degrees of development of trail laying behavior, 
they are admirably suited for studies of odor trail laying. 
The role of odor trail laying in the social biology of ants has been 
demonstrated clearly by Wilson (1962) using an artificial trail tech- 
nique. Previous investigations had demonstrated that the trail sub- 
stances of the myrmicine Solenopsis saevissima (Fr. Smith) (Wilson, 
1959) and several Dolichoderinae (Wilson and Pavan, 1959) orig- 
inated as glandular secretions. Employing similar techniques, Moser 
and Blum (1963) demonstrated that the odor trail substance of one 
attine, Atta texana (Buckley), was a product of the poison glands. 
4 Based on research supported in part by U. S. National Science Foundation 
Grant No. G22074. 
department of Entomology, Louisiana State University, Baton Rouge. 
Louisiana. 
3 U. S. D. A. Forest Service, Forest Insect Laboratory, Alexandria, Louisiana. 
4 Departmento de Entomologia, Universidad de Costa Rica, San Jose, Costa 
Rica. 
Manuscript received by the editor May 14, 1963. 
