INSECTS. 



221 



insects, and these soon check the increase of these pests, and next they 

 reduce their numbers so that they no longer can produce great dam _ 

 and then, having nothing to feed upon, the ichneumon-flies themseh 

 begin to disappear, and the balance is again restored. It is in this wa\ 

 that these inconspicuous forms are of more avail in reducing the numbers 

 of noxious insects than any act of man can be. 



The ants are by far the most interesting of all the insects, and to th 

 consideration we shall have to devote considerably more space than to any 

 of the other forms. All are familiar with the general appearance of these 

 animals, and hence no illustrations will be necessarv. The ants arc emi- 

 nently social animals, forming large colonies, between the various numbers 

 of which there is apparently the most perfect agreement, every individual 

 working for the good of the whole. To carry out their domestic economv. 

 there is, besides the males and females (whose sole duties are the perpetu- 

 ation of the species), a vast number of workers, who perforin all the labor 

 of the colony. The males and females are winged, but the workers — the 

 forms most familiar to us — are without wings. These last may differ 

 considerably among themselves ; for while in some species only one kind 

 of worker occurs, in others there may be larger workers, or 'soldier-.' 

 which at once recall the soldiers among the white ants. Indeed, in many 

 features of their economy these two groups, although structurally ><> 

 diverse, closely parallel each other. In the sauba ant of tropical America 

 the complexity is carried still further, as there are here three kinds of 

 workers, but it is not yet known what are the functions of the two largi 

 kinds. 



Among bees, as is well known, there is but a single female, or queen, 

 to a colony or hive; but among ants there may be several, while on the 

 other hand, a colony of ants may exist without a queen. At certain 

 seasons of the year the newly fledged males and females will come out 

 from the nests in enormous numbers and take their 'marriage flight, tin- 

 male and female flying away together. In other cases, they fly separately, 

 the pairing taking place before or after the flight. The rest of the history 

 is involved in uncertainty. The females on alighting immediately begin 

 to dig their burrows in the earth, using their mandibles for the purpos 

 but it seems probable that they are not able in all cases to found a new 

 colony, although in some instances it has been shown that they can. 

 digging, the queen finds her large wings an incumbrance, and so she 

 them off with her mandibles, assisting the operation by contortions of the 

 body. Her subsequent life is to be underground, and she is merel; - - 

 off useless incumbrances. 



Occasionally a queen has been seen to be adopted by a colony. 



