Wasps, Bees, and Ants 



553 



of safe transportation due to the migrating habits of majiy of their host 

 species. 



The myrmecophilous (ant 's-nest-inhabiting) insects are limited to no 

 single order. Of the total of 1177 insect species recorded by Wasmann 

 in 1900 as living for part or all of their life in ants' nests, 993 are beetles, of 



FIG. 758. Ant-guests; at left, Psyllomyia testacea, female; next at right, Ecitomyia 

 wheeleri, female; at extreme right, male of last-named species. These two insects 

 are species of flies of the family Phoridae, the females of which have become 

 extremely degenerate because of their myrmecophilous life. (After Wheeler; 

 much enlarged.) 



which the families Staphylinidae (rove-beetles), Pselaphidae, Paussidae, Clavi- 

 geridae, Histeridae, Silphidae, Thorictidae, Lathridictidae, and Scydmaenidae 

 make up all but 100 species, these latter representing 22 

 other families; 76 are Hemiptera, of which 15 are plant- 

 lice and scale-insects; 39 are Hymenoptera, of which 22 

 are other ant species; 26 are Lepidopterous larvae, 20 

 are Thysanura, 18 Diptera, 7 Orthoptera, i a Pseudo- 

 Neuropteron, 34 are mites, 26 are spiders, and 9 are 

 isopod crustaceans. While most of these only derive 

 advantage from this commensalism with ants, some, and 

 notably the small Paussid, Clavigerid, Pselaphid, and 

 other beetles, live truly symbiotically with their hosts, 

 being of immediate reciprocal benefit to them. 

 These little beetles, many of which show most amazing 

 modifications of body structure (Figs. 755, 756) (such 



modifications, usually degenerative, are displayed also by Fl 5.-, 759- Larva of a 



,, . , ' _,, . , _. ,. Phond fly attached 



numerous other ant guests, particularly Phond flies (Figs. to the larva of the 



757> 75 8 )> m adaptation to this extraordinary life, ant ' Pachycondyla 



u_. ,.,. ,., harp ax. (After 



secrete a sweet substance which is greedily eaten by wheeler; much en- 



the ants. The hosts in return care for, clean, and feed larged.) 

 by regurgitation the curious little beetles. 



The "wonderful" and "marvelous" character of the behavior of the 



