GARDEN INSECTS 211 



the various mildews which the honeydew invites, and the 

 beauty of the foliage is destroyed as well. Ants attend 

 the aphids for this excretion, and some species of ants 

 also preserve the eggs in their nests over winter and 

 carry the newly hatched plant lice to their food plants in 

 the spring. Bees sometimes make honey from honeydew, 

 generally of a rank, inferior quality, but pay no attention 

 to the aphids themselves. 



From the bodies of many species of aphids are also pro- 

 duced white, powdery, downy, or flocculent growths that 

 may serve to conceal the insect or render it unpalatable 

 to birds. The woolly aphids of the alder, beech, and apple 

 are good examples of this. 



A number of aphids have the strange instinct of migrat- 

 ing from one kind of plant to another. The green apple- 

 tree aphid thus migrates to the grasses to spend the 

 summer and in the fall comes back to the apple to feed 

 for a time and deposit its eggs. In a similar way the hop 

 aphid, Phorodon humuli, feeds upon the plum in the 

 spring, migrates to the hop to spend the summer, and 

 returns to the plum in the fall. 



With such small insects we cannot hope to do much by 

 way of description or classification beyond naming, them 

 roughly from the plants upon which they are found, but 

 their powers of multiplication and their relations to lady 

 beetles and other natural enemies are valuable lines of 

 study. We may take them up in connection with the life 

 story of one common and important species, the cherry 

 aphid, Mysus cerasi. 



In October ask the children to hunt over cherry trees 

 in the neighborhood and bring twigs infested with the 



