184 
Psyche 
[Vol. 91 
Discussion 
Can a comparison of behaviors within the Cephalotini contribute 
to an understanding of the phylogeny within the tribe or of the 
evolution of morphological worker castes? Including the behavioral 
data reported here, information is available for the three major 
genera of cephaiotines: Procrvpt ocerus, Cephalotes, and Zacrvp- 
tocerus. It is now possible to compare and integrate behavioral with 
morphological data in considering phylogenetic relationships among 
cephaiotines. 
Only behavioral characters that do not occur in all members of a 
group can be useful in constructing alternative paths of evolution. 
Six such characters known for three species of cephaiotines are 
listed in Table 3. First, 1 will use these characters to illustrate overall 
behavioral similarities between species. Then, the polarity (ancestral 
vs. derived state) of these characters will be surmised and used to 
construct behavioral cladograms (Fig. 2). Finally, the evolutionary 
relationships suggested by the cladogram can be used to re-examine 
our assumptions about the evolution within the cephaiotines and 
their diverse morphological worker castes. 
P. scahriusculus has been characterized as morphologically diver- 
gent (Kempf, 195 1 ), quite discrepant (Kempf, 1 973), and primitive 
(Corn, 3976; Wilson, 1976). In its behavior, however, it shares a 
remarkable number of traits with the advanced species, Z. varians 
(Table 3). Table 3 indicates that P. scahriusculus and Z. varians 
share four of the six discrete behavioral characters listed, two of 
Table 3. Comparison of behavioral characters among three cephalotine species, 
representing the three major genera. The six behaviors that are listed may have phylo- 
genetic significance. An asterisk (*) indicates which behavioral state is considered 
derived. Note that Procryptocerus scahriusculus and Zacryptocerus varians share 
four characters, while Z. varians and Cephalotes atratus share two. P. scahrius-culus 
and C. atratus share none of the six behavioral states. Abbreviations given are used 
in Figure 2. 
Cephalotes 
Zacryptocerus 
Procryptocerus 
Abdominal trophallaxis (at) 
no 
(yes* 
yes*) 
Adult transport (car) 
yes 
(no* 
no*) 
Inlrabuccal pellets 
no* 
(yes 
yes) 
Lay trophic eggs 
no* 
(yes 
yes) 
Stridulate (str) 
(no* 
no*) 
yes 
Abdominal self-groom (ag) 
(no* 
no*) 
yes 
