262 NATURE-STUDY REVIEW [13:6— Sept., 1917 



The writer especially recommends these insects for school room 

 study and demonstrations. They are very easy to rear and have 

 some exceptionally interesting habits. The adults should be 

 placed in small vials, 4 oz. being desirable. Leaves with plant 

 lice on them should be put into the vials daily for food. Females 

 with greatly distended abdomens may be expected to oviposit very 

 soon. By a little close observation, one may see the process of 

 oviposition. The light green, elongate, oval egg rests on a com- 

 paratively long, clear stalk. Oviposition may continue for six 

 weeks. When ten or more eggs have been desposited in one vial, 

 the adult should be removed to another vial. The eggs should be 

 closely watched as the little embryo may be observed in the eggs 

 after the second day. They are outlined in red or reddish brown. 

 After the fifth day, the eggs may be expected to hatch. 



There is a specialized structure called an egg burster that enables 

 the hatching process to take place. In eggs ready to hatch, it will 

 be seen as a short dark line on the ventral side between the eyes. 

 If an egg be taken from a group where most are already hatched, 

 the operation of this device may be observed under a microscope. 

 After hatching, it will be found, adhering to the cast off embryonic 

 molt in the opening of the egg shell. This may be mounted in 

 balsam or glycerine jelly and studied. 



The hatched larva? rest for a time on the egg shell but as they 

 grow hungry, they become restless and finally come down the stalk. 

 Immediately they go in search of plant lice or any soft-bodied small 

 insects, not excepting young larvae of their own kind, which they 

 pierce with their two sickle shaped jaws which are curved tubes and 

 suck out the body fluids. Under a microscope, one can see the 

 juices running up the jaws and sometimes the contraction and 

 expansion of the pharynx which constitutes the sucking pump. 

 The larvae must be fed daily with 20 or more small plant lice. 

 Because of their ravages among aphid colonies, the larvae have been 

 given the very appropriate name of "Aphis Lions." 



On about the third day after hatching or a little later, each larva 

 will shed its skin. One can readily ascertain when a larva will molt 

 by the peculiar glassy appearance of the body wall and by the way 

 the black setae are folded across the back just underneath the old 

 skin. The larva, when ready to molt, glues the tail fast to the 

 glass and then by a series of movements, pulls the body loose from 

 the old skin. Then the body is shifted forward and this causes the 



