Wasps, Bees, and Ants 



545 



up by the Leptothorax. The latter then dismounted, ran to another Myrmica, 

 climbed onto its back, and repeated the very same performance. Again it 

 took toll and passed on to still another Myrmica. On looking about in 

 the nest I observed that nearly all the Leptothorax workers were similarly 

 employed." Wheeler believes that the Leptothorax get food only in this 

 way; they feed their queen and larvae by regurgitation. The Myrmicas 

 seem not to resent at all the presence of the Leptothorax guests, and indeed 

 may d:rive some benefit from the constant 

 cleansing licking of their bodies by the sham- 

 pooers. But the Leptothorax workers are careful 

 to keep their queen and young in a separate cham- 

 ber, not accessible to their hosts. This is prob- 

 ably the part of wisdom, as the thoughtless 

 habit of eating any conveniently accessible pupae 

 of another species is wide-spread among ants. 



The third family, Camponotidae, a large one, 

 includes a majority of the familiar ants of 

 eastern North America. The large black car- 

 penter-ant, Camponotus pennsylvanicus (Fig. 

 749), which builds extensive nests in logs, 

 stumps, building timbers, and even living trees; 

 the large black-and-red mound-builder, For- 

 mica exsectoides, whose ant-hills are from five to 

 ten feet in diameter; and Lasius brunneus, the 

 little brown ant "whose nests abound along the 

 borders of roads, in pastures, and in meadows," 

 are all familiar Camponotid species. The last- 

 named one is known in the middle states as the 

 corn-louse ant because of its interesting associa- 

 tion with the wide-spread corn-root louse, Aphis 



maidi-radicis. In the Mississippi valley this 



1 

 aphid deposits in autumn its eggs in the ground 



in corn-fields, often in the galleries of the little brown ant. The following 

 spring, before the corn is planted, these eggs hatch. Now the little brown 

 ant is especially fond of the honey-dew secreted by the corn-root lice. So when 

 the latter hatch in the spring, before there are corn-roots for them to feed 

 on, the ants with great solicitude carefully place them on the roots of cer- 

 tain kinds of knotweed (Setaria and Polygonum) which grow in the field, 

 and there protect them until the corn germinates. They are then removed 

 to the roots of the corn. 



A curious Camponotid is the honey-ant, Myrmecocystus melliger, found 

 in the southwestern semi-arid states. McCook studied these ants in the 



large black carpenter-ant, 



9 pon ,r tu * 

 (After McCook.) 



