may expect the discovery of the gipsy moth and the 

 brown-tail moth in New York State. These two insects 

 were accidently brought to this country in recent years 

 and are now widely spread and most injurious in the 

 New England States. 



Plant lice or aphids, unlike caterpillars, live upon the 

 sap of plants which they suck through a tiny beak from 

 the living cells in the leaf or even the inner bark of many 

 trees and shrubs. These tiny insects usually occur in 

 great numbers on the leaves and, when numerous, pro- 

 duce a large amount of a sweet, sticky substance known 

 as honeydew. This honeydew smears the leaves and 

 may even wet the ground beneath. Ants frequently 

 protect plant lice and feed upon the honeydew they 

 produce. A sooty fungus grows in the honeydew and 





White-marked tussock moth; male 

 female on the right 



blackens the affected foliage. These insects are small 

 and very weak, and yet they often become so abundant 

 as to cause very serious injury because of the large 

 amount of sap they suck from the plants upon which 

 they occur. Sometimes a large part of the foliage of 

 many elms and maples is nearly destroyed by these tiny 

 enemies. 



We can not describe here all the insects which feed 

 upon ornamental trees and shrubs. A few are injurious 

 almost every year, while a much larger number may cause 

 serious damage only now and then, long periods some- 

 times passing before a pest becomes abundant again. A 

 study of insects shows that all produce eggs and from 

 these hatch small maggots, grubs or caterpillars. These 

 latter require a large amount of food, since this is the 

 stage or condition in which insects grow. We should 

 remember that small flies never grow to be large flies. 

 26 



