84 ELEMENTARY STUDIES IN INSECT LIFE 



of branches below the aphids. Sometimes this fluid is 

 noticeable on the stone walks above which there are 

 trees in which are plant-lice. This method of ants con- 

 ducting 1 their farming system the student can observe for 

 himself. Whenever ants are found going- up and down 

 a tree, it may be taken for granted that they are going 

 and returning from aphid pastures. The redbud tree is 

 a favorite with some species of aphids. A branch of this 

 upon which aphids and ants are found can be removed 

 and the stem placed in a vessel containing water. The 

 leaves will remain green for some time and the relations 

 existing between aphid and ant can be observed. 



If the student has not already discovered it, his at- 

 tention is now called to the fact that there are three 

 classes of ants in a colony : males, females, and workers. 

 The first two are winged and the workers are wingless. 

 During the summer it will be possible for the student to 

 observe a number of ants coming forth from the hives 

 and taking flight. Many of the colonies of ants are 

 doing this at the same time. It is during this flight 

 that the female, commonly called the queen, is fertilized. 

 She drops to the earth, tears off her wings, these being 

 no longer required, and endeavors to secure a place to 

 deposit her eggs. She is sometimes taken into a colony 

 of her own species, and sometimes she starts a new 

 colony from the eggs which she lays. Comstock has 

 shown in a series of interesting experiments that it is 

 possible for a queen of the carpenter ant 1 to build her 

 cell, lay her eggs and bring forth the first of her brood 

 without taking any food whatever. The cell she builds 



^Camponutus pennsylvanicus. 



