1964 ] 
Bluiiij Moser , Cordero — Chemical Releasers 
3 
Table i. Response of attine workers to artificial trails prepared from three abdominal glands. 
No. of Positive Responses 
(Total IV orkers Responding in Parentheses) 
Species 
No. of Tests 9 
Hind Gut 
Poison Gland 
(Plus Vesicle) 
Dufour’s Gland 
Cyphomyrmex rimosus 
8 
0 
8(69) 
0 
Trachymyrmex septentrionalis 
10 
i( 3 ) 
10(83) 
0 
A cromyrrnex octospinosus 
10 
0 
10(78) 
0 
Atta cephalotes 
10 
2(7) 
10(90) 
0 
end after crossing it during a three minute observation period. Al- 
though the major workers of Atta texana are too excitable to be 
employed in the artificial trail test (Moser and Blum, 1963), the 
medium workers of A cromyrrnex octospinosus and Atta cephalotes 
were found to be much more suitable than their minor workers for 
these tests. The results of these experiments are presented in table 1. 
The poison glands are clearly the source of the odor trail substances 
in all four attine species. Ants frequently followed the artificial odor 
trails during the entire course of the observation period. When 
workers had run the entire length of the trail they would invariably 
overshoot and, often after milling around, they would encounter the 
artificial trail again and resume trail following. 
SPECIES-SPECIFICITY OF THE ODOR TRAIL SUBSTANCES 
Cross-species tests with artificial odor trails were made with the 
four attine species principally employing the circular trail technique 
of Moser and Blum (1963). Poison glands (and vesicle) were dis- 
sected out of freshly-killed or frozen workers and after rinsing in 
saline were crushed in 0.5-1. o ml. of methylene chloride. Aliquots of 
0.1-0.2 ml. of the methylene chloride solution of the poison gland con- 
tents were then applied with a pipette to a circle 6" in diameter and 
the solvent was allowed to evaporate. Subsequently, 10 ants were 
introduced into the middle of the circle and the numbers of ants 
which, after encountering the circle, followed the circular trail for at 
least half its length were recorded. 
As the data in table 2 demonstrate, the odor trail substances in the 
attine genera are not generic or species-specific. Although the arti- 
ficial trails prepared from extracts of the poison glands of Atta and 
’Ten workers per replication. 
