164 



riYMENOPTERA 



individuals weigh 1 gramme, and it is probaljle that a nest 



may include millions of specimens. 



The genus Apliacno<jaster^ and its immediate allies include the 



harvesting ants of Europe and North America : they form subter- 

 ranean nests consisting of iso- 

 lated chambers connected by 

 galleries ; some of the chambers 

 are used as store -houses or 

 granaries, considerable quantities 

 of corn, grass, and other seeds 

 Ijeing placed in them. A. 

 struetor and A. harharus have 

 been observed to do this in 

 Southern Europe by Lespes, 

 Moggridge, and others. 



In the deserts about Algeria 

 and Tunis a harvesting ant, 

 Apliacnogaster (Messor) arcn- 

 arius, is an important creature : 

 its subterranean dwellings are 

 very extensive, and are placed 

 at a depth of several feet from 

 the surface. Entrance to these 

 dwellings is obtained by small 

 holes, which are the orifices of 



Fig. 70. — Aphaenogaster {Messor) harharus. n • o ^ • ^ n 



Algeria. A, male ; B, winged female ; galleries many feet in length : 

 C, large worker or soldier ; D, small the holcs are surrounded by 



worker, x^. n f. i • • 



pellets 01 sand projecting some- 

 what above the general surface, and consequently making the 

 places conspicuous. The subterranean w^orks occupy an area of 

 fifty or a hundred scjuare yards excavated at a depth of three to 

 six feet. In these immense nests there exists a form of worker, 

 of very small size, that never comes to the surface." 



Pogonoinyrmcx hirhatus and other species have been observed 

 to do harvesting in North America. After the workers of F. 

 harhatus have taken the seeds into the nest they separate the 

 husks and carry them out, depositing them on a heap or kitchen- 



' Until recentlj' tliis genus was generally known as Atfa, but this name is now 

 applied to the leaf-cutting ants, that were formerly called Oecodoma,. 

 ' Forel, Bull. Soc. Vaudoise, xxx. jjp. 29-30, 1894. 



