46 NEW YORK STATE MUSEUM 



tended and thorough work means heavy appropriations, practical 

 only in the more valuable residential or business territory and 

 utterly beyond the resources of poorer cities and towns having 

 extended tracts of low-priced lands. The discrimination of an 

 entomologist is not needed to note the widespread and in some 

 instances extremely severe devastations by both the gipsy and 

 the brown-tail moth (plates 10, 11, 12 and 13). The Federal Gov- 

 ernment has in recent years been spraying strips two hundred 

 feet wide on each side of the more important highways for the pur- 

 pose of preventing spread by vehicles and incidentally this 

 serves in a considerable measure to obscure the extent of the 

 injury. Last summer there were hundreds and in some instances 

 thousands of acres of woodland defoliated, although the strips 

 along the highways were in excellent leaf, due to the thorough 

 spraying with poison. These large areas of stripped forest or 

 orchard lands show what would be the result were there a re- 

 laxation of control measures in the well-protected territory. In 

 other words, relative immunity is extremely costly. 



The conditions would be much worse than obtain at present, 

 in spite of the enormous expenditure, were it not for important 

 advances in methods during the last few years. The develop- 

 ment of very efficient h'igh-powered spraying outfits has mate- 

 rially reduced the cost of sprajnng and made it possible to protect 

 woodlands, in large measure, for about $7 an acre. It has been 

 found that pure or unmixed plantings of pine, if protected from 

 invading hosts of caterpillars, are immune from injury (plate 

 12). Ash is not troubled by the gipsy moth, while the work of 

 the last two years has shown that maple, hickory and locust are 

 rarely damaged. Chestnut also appears to suffer but little if the 

 young caterpillars have nothing else to feed upon. Apple, oak, 

 birch and willow are favorites of both gipsy and brown-tail moth 

 caterpillars and under favorable conditions may be the indirect 

 cause of serious injury to adjacent, relatively immune trees. 



There is also the possibility that the numerous parasites im- 

 ported during the last few years may shortly prove efficient aids 

 in checking these pests. It should be understood that conditions 

 in the infested district are serious, especially in sections where 

 low values prohibit expensive control measures. 



Means of preventing spread. The prevention or hindrance of 

 the spread of such an insect as the gipsy moth is most important 

 and in large measure practical. The female does not fly and as 



