96 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 85 



more the likeness is almost always detailed and remarkable, however 



it is attained, while the methods made use of differ absolutely 



We are compelled to believe that there is something advantageous in 

 the resemblance to an ant, and that Natural Selection has been at 

 work. The phenomena do not merely disprove all other suggested 

 causes of change ; they constitute the most powerful indirect proof of 

 the operation of Natural Selection." 



If the above reasoning has any application so far as the attacks of 

 predators upon ants are concerned, we should expect some evidence 

 that ants are relatively free from such attacks. Let us see what is the 

 case. Beginning in the very homes of the ants we find, among crea- 

 tures habitually living in ant colonies, that numerous Staphylinid 

 beetles devour the brood, besides crippled and even normal ants ; the 

 larvae of Clythrinae (Chrysomelidae) feed on the eggs; lycaenid 

 caterpillars and paussid beetles eat the eggs and larvae. Numerous 

 ectoparasitic mites and some chalcidids also attack the ants in their 

 domiciles, as well as entoparasites among the Strepsiptera, Phoridae, 

 Conopidae, Braconidae, Chalcididae. Proctrotrupidae, and Nematoda. 

 Ants have very important predatory enemies in their own ranks, 

 namely the doryline and slave-making ants. Ant-lions of the family 

 Myrmeleonidae, Diptera with similar habits, predacious wasps, es- 

 pecially the Crabronidae, assassin bugs, ground and tiger beetles, and 

 spiders are serious invertebrate enemies of ants. Most toads, frogs, 

 and lizards, the amphisbaenids, and certain snakes feed upon ants ; 

 fishes take them when opportunity affords ; practically all birds eat 

 ants, several groups as the song thrushes, ant-thrushes (Formi- 

 cariidae), and woodpeckers depending upon them for a large part 

 of their food ; in the same way most of the insectivorous mammals 

 are fond of ants and several groups of this phylum are specialized 

 ant eaters, namely Echidnidae (spiny anteaters) auKjng the Mono- 

 tremata, the banded anteater {Mynnccohiiis) among the Marsupialia. 

 and nearly the whole order of Edentata (antbears, pangolins, and 

 armadillos).' 



In fact it would be difficult to name a group of insects that is so 

 thoroughly preyed upon as the ants, and impossil)le to name one that 

 has so many specialized foes scattered through the various animal 

 phyla. So far as predatory attack is concerned, it would seem that 

 ant-mimics court rather than avoid danger. To recapitulate: if there 

 is any virtue in the protective adaptations of the " aggressive, abun- 



* For a comprcliensive account of " The predacious enemies of ants." see 

 Bequacrt, Bull. Amcr. Mus. Nat. Hist., vol. 45, pp. 271-331, 1922. 



