424 Willi am Morton Wheeler 



in which the individuals that represent the reproductive organs 

 {i.e., the males and queens) of the colony considered as an organ- 

 ism of a higher order, are castrated by parasites, we should perhaps 

 include also the Lasius colonies containing mermithogynes and 

 the queens of Bombus infested with Sphaerularia described in the 

 foregoing paragraphs. But in these cases it is merely prospective 

 colonies, so to speak, which are castrated, since neither the mer- 

 mithogynes nor the parasitized Bombus queens have as yet be- 

 come mothers of colonies. For this reason I have treated them 

 as cases of individual parasitic castration. Here belongs also 

 the production of pseudogynes in Formica colonies infested with 

 the peculiar myrmecophilous beetle? of the staphylinid tribe 

 Lomechusiiii (Lomechusaand Xenodusa) which I have considered 

 at length in a former paper ('07). These beetles tend to sup- 

 press the development of the annual brood of virgin queens since 

 the worker ants of parasitized colonies either neglect the queen 

 larvae or endeavor to convert them into workers, after the period 

 during which this change can be successfully accomplished has 

 passed. The results of this behavior is the production ot the non- 

 viable pseudogynes and the gradual degeneration of the colony. 

 In this case also the colony is not castrated, but the mothers of 

 prospective colonies may be said to suffer from misapplied alimen- 

 tary castration. 



Leaving all these cases out of account we have left only those 

 in which a parasitic colony of insects prevents the development 

 of or destroys the fertile sexual individuals of the host colony- in 

 which it hves. As parasites of this type I may mention the vari- 

 ous slave-makingants (Formica sanguinea andPolyergus rufescens 

 and their various varieties and subspecies), the temporary social 

 parasites (Formica rufa, exsecta, exsectoides, etc.) and the perma- 

 nent social parasites of the genera Anergates, Wheeleriella, Epi- 

 pheidole, Sympheidole and Epoecus. There are other social para- 

 sites that do not destroy the reproductive individuals of the host 

 colony, for example, the bees of the genus Psithyrus, which hve 

 in the nests of bumble-bees, and among ants such species as Lep- 

 to thorax emersoni, Formicoxenus nitidulus and Harpagoxenus 

 sublevis. Stillother ants, such as the species of Strongylognathus, 



