TRUE GUESTS, ECTO- AND ENTOPARASITES. 



407 



their symphily, their greater initiative towards the ants, and the close 

 imitation of their behavior. The last peculiarity is especially apparent 

 in that they do not, like Loinccliiisa, Clai'igcr and Amphotis, beg the 

 ants for food merely by stroking them with their antennae, but also 

 raise their fore feet after the manner of ants, and stroke the cheeks of 

 the regurgitating hosts [Fig. 240]. On this account they are treated 

 by their normal hosts like ants and not like ant-larvae." 



Five species of Lomechusa and a greater number of species and 

 varieties of Atemeles have been described. Of these L. strumosa (Fig. 

 238) is the best known. It is exceedingly rare in England, but common 

 in many places on the Continent ( Holland, Luxemburg, Saxony, 

 Switzerland). Its normal host is the blood-red slave-maker, Formica 

 sanguined, though very rarely it may be found in the nests of F. rufa 

 and pratensis. Of the species of Atemeles, pubicollis (Fig. 239) 

 breeds in the nests of F. rufa, parado.nts in those of F. rufibarbis and 

 emarginatus in those of F. fitsca. The American Xeuoiiiisa is also 

 represented by several species, the best known of which is A', cava 

 (Fig. 241). Like Atemeles, 

 this beetle has two hosts, but 

 both of these are Campono- 

 tine ants. It passes the 

 winter in the nests of Cain- 

 ponotus pennsylvanicus or 

 noveboraccnsis and breeds 

 in the early summer in the 

 nests of Formica species. 

 1 have seen its larvae in the 

 nest of F. inccrta. They 

 have longer appendages than 

 Lomechusa larvae and can 

 walk about and beg the ants 

 for food by raising and 

 stroking their cheeks with 

 the anterior pair of feet. 

 Like the larvae of Atemeles 



FIG. 243. Larvje and pupse of Pacliycondyla 

 liarpa.r and its commensal Metopina pachycon- 

 dylcc. (Original.) The Pachycondyla larvae 

 marked a. have each a Metopina larva around 



and Lomcchlisa thev de- t ' le nec ^ > ^. isolated Metopina larva: c, Meto- 

 pina puparium ; d, cocoon of Pachycondyla. 



vour the ant brood. 



There is evidence that colonies of inccrta infested with Xcnodnsa 

 tend, like those of sanguined infested with Lomechusa, to produce pseu- 

 dogynes. These queer, mongrel forms (Figs. 57, b ; 242 ; 267, b) are an 

 abortive combination of the female thorax with the stature, gaster and 

 head of the worker. They are usually paler in color than the normal 



