1987] Topoff, Bodini, Sherman, & Goodloe — Polyergus 267 
its home nest on the same bearing. But Harkness and Maroudas 
(1985) show that the sideways search pattern decreases the time for 
the return trip, and the same argument could easily hold for Polyer- 
gus. In addition, the linear phase of the scout’s route ensures min- 
imum overlap among the sectors searched by all of the scouts on any 
given day. 
Polyergus is also similar to Cataglyphis (and other formicine 
ants) in its ability to orient to polarized light, and we recently dem- 
onstrated that scouts use visual (and not chemical) orientation dur- 
ing their outbound and return run, and when leading the raid swarm 
back to the target nest (Topoff et al. 1984). Further support for this 
hypothesis stems from our map of the complete route taken by a 
scout on July 13 (Fig. 2), in which a different path was taken for 
each of the scout’s three runs. A model based upon chemical cues 
would predict a single path for the outbound run, return trip, and 
slave raid respectively. However, because a chemical trail is depos- 
ited during the slave raid, we have not ruled out the possibility that 
scouts might follow trails deposited on previous days. 
The initiation of slave-making raids by scouts has so far been 
reported for the myrmicine genera Strongylognathus, Harpagoxe- 
nus, Leptothorax, Epimyrma, and Chalepoxenus, and in the formi- 
cine genera Formica, Polyergus, and Rossomyrmex (see review by 
Buschinger et al. 1980). In both subfamilies, details of scouting show 
several striking similarities. For example, scouts of the myrmicine 
ant Harpagoxenus sublaevis tend to be experienced workers which 
are at least one year old (Buschinger 1968; Buschinger and Winter 
1977). This is almost identical to the findings of Kwait and Topoff 
(1984) for the formicine Polyergus lucidus, in which ants functioned 
as scouts only during their second season after eclosing. 
A second convergence between the two subfamilies concerns the 
role of scouting as a prerequisite for raiding. In a laboratory study 
of the myrmicine species Harpagoxenus americanus and Lepto- 
thorax duloticus, Alio way (1979) recorded a total of 23 slave raids. 
For both genera, scouting preceded all of the slave raids, and scout- 
ing never took place when raids did not occur. In a similar study 
with P. lucidus, Kwait and Topoff (1984) removed scouts from 
laboratory nests on each of 7 days, during which time no slave raids 
occurred. Furthermore, observations showed that 25 out of 27 raids 
were directed towards Formica schaufussi nests that were scouted 
on the same day. The remaining two raids were directed at target 
