THE TEMPORARY SOCIAL PARASITES. 447 



been regarded as an exceptional or abnormal occurrence till very 

 recently, when Santschi (1906, Forel, 1906^) discovered several mixed 

 colonies of varieties of these species (B. atlantis and T. nigerriinitin ) 

 in the Tunisian desert, and showed by a series of surprising observa- 

 tions that they were cases of temporary parasitism. The Bothrio- 

 myrmex queen, on descending from her nuptial flight, wanders about 

 on the ground till she finds a Tapinoina nest and then permits herself 

 to be seized and " arrested " by the Tapinoina workers. These then 

 proceed to drag her into their burrow by her legs and antennae. After 

 entering the nest the parasite may be attacked from time to time by the 

 workers, but she takes refuge on the brood or on the back of the Tapi- 

 noma queen. In either of these positions she seems to be quite immune 

 from attack. This observation throws light on certain peculiarities in 

 the behavior of F. consocians, for this insect also mounts the brood 

 pile as soon as she enters the incerta nest and when in this position is 

 never molested by the alien workers. Santschi observed that the 

 Bothriomyrmex queen often spends long hours on the back of the large 

 Tapinoina queen and that while she is in this position she busies herself 

 with sawing off the head of her host ! By the time she has succeeded 

 in accomplishing this cruel feat, she has acquired the nest odor and is 

 adopted by the Tapinoina workers in the place of their unfortunate 

 mother. The parasite thereupon proceeds to keep them busy bringing 

 up her brood. They eventually die of old age and the nest then 

 becomes the property of a thriving, pure colony of Bothriomyrmex 

 atlantis. The queen of this species, as Santschi has shown, is mimetic 

 like that of consocians, being but little larger than the Tapinoma 

 workers and provided w r ith an odor like that of the host species, though 

 this odor is lacking in her own workers. Santschi has thus been able 

 actually to witness the elimination of the host queen. But the method 

 employed by Bothriomyrmex in accomplishing this is not universal 

 among parasitic species, as we shall see when we come to his interesting 

 observations on the permanent social parasite Wheeleriella. 



5. Aphaenogaster. The female of the Myrmicine antAphccnogaster 

 tennesseensis (Fig. 264), in being deep red and of very small size, with 

 a glabrous body and huge, flattened epinotal spines protecting the vul- 

 nerable abdominal pedicel, is so unlike the females of any other members 

 of the genus Aph&nogaster that she was originally described by Mayr 

 as the type of a distinct species (A. levis). These peculiarities suggest 

 temporary parasitism and this is borne out by the observations of 

 Schmitt and myself (1901^). Schmitt found near Beatty, Pa., a small 

 mixed colony of A. tennesseensis and A. picca, a variety of fnlra and 

 one of the commonest ants in the Northern States. He was impressed 



