1927] The Slave Raids of Harpagoxenus americanus 
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been taken in Finland (Nylander), Denmark (Meinert), Sweden 
(Stolpe and Adlerz), Saxony, West Prussia, Bohemia (Viehmeyer) 
Karnten, Austria (Wolf), and the Swiss Engadine (Emelius). 
In this last location it occurs at an altitude of 1600-1700 meters. 
The pioneer observer of sublcevis was Adlerz, who in 1896 con- 
ducted numerous experiments on these insects in artificial nests, 
supplemented by observations in the field. He found that in 
the mixed colonies the slave ant was usually L. acervorum, oc- 
casionally L. muscorum and rarely L. tuber urn. Normal deflated 
Harpagoxenus queens were never present, their place in the 
colony being taken by the ergatoid female, a wingless worker- 
like insect possessing ocelli and a receptaculum seminis. Alderz 
further showed that the sublcevis workers, if forced to do so 
through the absence of slaves, are able to feed themselves but 
do not care for the brood. This is normally tended by the slaves 
who feed the larvae with regurgitated material and fragments 
of insects. This last observation was later confirmed by Vieh- 
meyer, who amplified the work of Adlerz by discovering, near 
Dresden in 1906, the true winged queens of sublcevis which 
Adlerz had supposed did not exist. Viehmeyer’s observations 
‘08) show that the actions of a sublcevis female in founding a 
colony closely parallel those of sanguinea queens. After the 
entrance of the parasitic female into the Leptothorax nest the 
workers attack her, but are eventually killed or driven away by 
the larger insect who then takes possession of the nest and 
brood. Adlerz had previously observed similar actions of the 
ergatoid females and had concluded that sublcevis customarily 
obtains its slaves in this manner. Such dispossession was 
thought to be fundamentally different from the raids of the 
amazons and sanguinary ants, who, after the pillage of the 
strange nest, return to their own with the plundered brood. 
Both Adlerz and Viehmeyer saw the “raids” of Harpagoxenus, 
if by this term we may translate the erofringstag of the former 
writer and the Raubzug of the latter. Unfortunately both these 
investigators interrupted the proceedings by disturbing the nests, 
with the result that it is impossible to tell from their observations 
whether they witnessed a true raid or the dispossession of Lep- 
tothorax nests by the Harpagoxenus. Indeed, Adlerz considered 
