1974] 
Haskins & Haskins — Myrmecia vindex 
259 
environment: substances which commonly evoke specific behavioral 
responses in higher ants? And if so are the responses elicited in 
Myrmecia essentially like those of higher ants? 
We have recently described one such set of reactions: the stimulus 
to attack behavior in Myrmecia gulosa elicited by formic acid, a 
normal exocrine defense product of its common prey-genus Campo- 
notus , but not, so far as can be determined, of M. gulosa itself 
(Haskins, Hewitt, and Haskins, 1973). The present investigation 
is concerned with the reactions of workers of a species of Myrmecia 
to substances which commonly stimulate necrophoric behavior in 
higher ants, such as oleic and related fatty acids. 
Wilson (1958) and Wilson, Durlach, and Roth (1958) demon- 
strated that when groups of workers of the Myrmicine ant Pogono- 
myrmex badius come into contact with formic acid, ethylamine, 
triethanolamine, phenol, n-butyric acid, n-valeric acid, n-caproic acid, 
or n-caprylic acid, absorbed on centimeter-square patches of filter 
paper, they exhibit weak to moderate alarm behavior, sometimes 
passing into digging behavior, concentrated about the squares. In 
the case of oleic acid — and of that substance alone — the ants 
transported the paper squares away from the nest to the kitchen 
middens. A fatty acid component — quite probably oleic acid — 
obtained from the decaying bodies of P. badius workers also elicited 
necrophoric behavior in Solenopsis saevissima. 
Blum, Doolittle, and Beroza (cf. Blum, 1970) fractionated dead 
workers of Solenopsis saevissima and determined that the releasers of 
necrophoric behavior were restricted to the rich free fatty acid 
fractions. Myristoleic, palmitoleic, oleic, and linoleic acids were 
present in these fractions, and all these acids possessed necrophoric 
activity in this species. 
Such a reaction to chemicals like oleic acid has obvious adaptive 
advantage for any ant, or indeed for any social insect inhabiting a 
closed nesting situation. Such chemicals can serve as sensitive “indi- 
cators” of objects in the nest — whether prey or remains of adult 
or immature members of the community — which are dangerously 
decomposed and should be removed. It seems plausible, therefore, 
that this behavior pattern may have been established very early in 
the social evolution of the Formicidae. Hence it seemed of particular 
interest to investigate it within the Myrmeciinae. 
Necrophoric Behavior in Myrmecia vindex 
The species Myrmecia vindex was chosen for several reasons. 
It is a common and wide-ranging form in western Australia, where 
