ANTS. 



queens and males, the larvae of which they therefore undoubtedly 

 devour or neglect, as they do in the case of all that seems to be super- 

 fluous." The absence of the conspicuous males and females of the host 

 species in nests infested with testaceus aids the investigator in search- 

 ing for the parasites, especially during late June and early July, when 

 the host specif- is rearing the sexual brood, for nests containing male 

 or female larvae or pupae of the Tetrainorhini may be quickly passed 

 over and attention concentrated on the nests in which these are absent. 

 \Yasmann has shown that testaceus is more resistant to unfavorable 

 conditions than its host. This suggests the feasibility of introducing 

 it into America, where T. cespitum has become thoroughly acclimated 

 and rather abundant, especially in some parts of the Atlantic States. 



II. Harpagoxenus (Tonwgnatluts). The two known species of 

 this genus are rare and very local ants, allied to Leptotlwra.r, the genus 

 to which their hosts belong. The workers are small, dark-brown, with 

 short legs and hairy bodies and are easily recognizable by their broad, 

 toothless mandibles and their peculiarly elongated frontal carinae, which 

 extend back to the vertex and there bend outward, forming scrobe-like 

 depressions for the short antennae. 



i. Harpagoxenus sublevis (Fig. 274). The habits of this ant have- 

 been studied by Adlerz (1886, 1896) and Yiehmeyer ( 1906, 1908). It 



FIG. 274. Harfiago.vciiiis sublcris. (Adlerz.) a. Male ; b, ergatoid female. 



was formerly supposed to be confined to boreal Europe, having been 

 discovered in Finland by Nylander (1848) and taken in Denmark by 

 Meinert (1860), and in Sweden by Stolpe (1882) and Adlerz (1886, 

 1887. 1896), but Viehmeyer has recently shown that it also inhabits 

 the heaths near Dresden. In the locality last mentioned it is always 

 found in the nests of Leptothorax acerz'ornm, and although this is its 

 common host in northern Europe, Alderz has observed it also in the 



