SURROUNDINGS OF GROWING INSECTS 241 



of the larvae form an important part of the activities of the 

 worker-insects. 1 In an ants' nest, consisting of galleries and 

 larger spaces excavated in the soil, in timber, or in plant 

 tissues, there are no special chambers of regular shape in which 

 the grubs lie protected. Eggs, larvae, and cocoons are carried 

 about by the worker-ants between their mandibles and de- 

 posited in whatever part of the nest seems for the time the 

 most suitable. In many ants' nests the larvae are segregated 

 according to age, and the relation of the adult workers to the 

 brood is much more intimate than among any other insects. 

 The larvae are not only fed but cleaned, and the workers of an 

 American species of Lachomyrmex, have been seen to " bring 

 larvae and pupae out on to the large crater of the nest about 

 9 p.m., and carry them leisurely to and fro, much as human 

 nurses wheel their charges about the city parks in the cool of 

 the evening ". The grubs of most ants differ from the 

 larvae of bees and wasps in the presence of hairs or spines of 

 varying and sometimes complex form often arranged on minute 

 tubercles ; these outgrowths of the cuticle, which are especially 

 evident in the younger larvae, serve to keep them from 

 direct contact with moist earth, to anchor them to the walls 

 of the nest, or to make it easier for the workers to take them 

 up in their jaws without injury. The food provided for the 

 larvae varies immensely among ants of different groups and 

 even of the same kind. Some, like wasp larvae, are carnivorous, 

 others feed on plant-tissues, others on fungi cultivated in the 

 nests, and others again on the secretions of other insects, the 

 honey-dew of aphids, for example. Very many insects which 

 provide such nutritive secretions live as guests in ants' nests, 

 and are carefully tended by the workers as sources of the 

 larval food-supply. In direct reference to the subject of this 

 chapter especial mention may be made of caterpillars of the 

 Lycacnidac (Blue Butterflies) which exude, from a gland 

 opening on the dorsal aspect of the eighth abdominal segment, 

 a sweet secretion ; this is used by many ants as food. Ants 

 attend these caterpillars on their food-plants where, as is 

 believed, they protect them from enemies ; some kinds of 

 ants also take the caterpillars into their nests. 



1 W. M. Wheeler : " Ants : their Structure, Development and 

 Behaviour ". New York, 1910. 



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