208 
Psyche 
[Vol. 89 
With respect to systematic relationships, the new species clearly 
supports “Emery’s rule,” under which socially parasitic ants are 
always closely related to their respective host species group. No 
characters linking L. faberi with European Doronomyrmex pads 
or Leptothorax kutteri could be found. The new species shares a 
characteristic structure in the petiole with the host species and with 
Doronomyrmex pocahontas. The Canadian species have two dis- 
tinct small teeth at the base of the anterior face of the petiole just 
above its articulation with the epinotum (fig. 1). These teeth are 
lacking in their European relatives. 
The holotype female, 2 allotype males and 1 worker, and voucher 
specimens of the host species are deposited in the Museum of Com- 
parative Zoology, Harvard University, Cambridge, Mass. (no. 
32758). 
5. Summary 
Male, female and worker of an apparently parasitic ant, Lepto- 
thorax faberi n. sp., are described. The new ant species was found in 
a queenright colony of Leptothorax muscorum (sensu lato) in 
Jasper National Park, Canada. It differs from the host species in its 
smaller size, in the shape of the petioles (figs. 1, 3, 4), in sculpture 
and coloration. The karyotype with a haploid number of 15 chromo- 
somes (fig. 5) is also different from that of the host species, which 
has n = 17 chromosomes. Very few workers have been raised in two 
laboratory colonies. Thus, L. faberi seems to represent an inquiline 
species. 
6. Acknowledgments 
I am grateful to my student, Karl Fischer, who assisted me during 
the collecting trip, and who also carried out the karyotype studies. I 
also thank the Jasper Park authorities for having tolerated our 
collecting activities. I am indebted to R. H. Crozier for critically 
reading the English text. 
References Cited 
Buschinger, A. 
1965. Leptothorax (Mychothorax) kutteri n. sp., eine sozialparasitische 
Ameise (Hymenoptera, Formicidae). Ins. soc. 12 : 327-334. 
