28 NEW YORK STATE MUSEUM 



figures obviously apply to fairly large tracts where favorable 

 conditions obtain. 



Small trees or a few trees can be protected from injury by the 

 removal, during the winter, of the egg masses, though this method 

 has obvious restrictions. Under certain conditions it may be advis- 

 able to offer prizes to school children for the collection of egg masses, 

 though in the case of the forest tent caterpillar it would generally be 

 found that the eggs are too high in the trees to permit much being 

 accomplished in this manner. Hundreds of cocoons of this pest are 

 spun in accessible places, and although the time during which effective 

 work can be done is limited to approximately two weeks, it is possible 

 to collect and destroy many of the insects in this stage with com- 

 paratively little effort. The best results will be secured if, instead 

 of burning the cocoons, they are placed in tight receptacles covered 

 with a wire netting having a one-fourth inch mesh. This would pre- 

 vent the escape of the moths and allow the numerous parasites, 

 usually occurring in the cocoons, to gain their freedom. 



Trees adjacent to badly infested areas can be protected from 

 the invasion of caterpillars by the application of sticky bands to 

 the tree trunks. One of the best banding materials is tree tangle- 

 foot. Coal tar can be used for this purpose though it should not be 

 applied directly to the trunk but be underlaid with a thickness of 

 stout building or roofing paper. Bands saturated with oils or greases 

 should never be applied directly to the trunks of trees, since there is 

 a probability of serious consequences resulting. A band of cotton 

 about 8 or 10 inches wide, tied tightly in the middle around the tree 

 and the upper portion turned down over the string and allowed to 

 hang loosely, is a fairly efficient obstacle to climbing caterpillars. 

 These bands are also of service in preventing caterpillars which fall 

 to the ground in high winds or which may be jarred from trees, from 

 reascending. 



Bibliography. A detailed account of this insect with a limited 

 bibliography is given in New York State Museum Memoir 8, volume 

 i, pages 106-15. 



Oil injury. The outbreak of forest tent caterpillars for the last 

 year or two has resulted in the adoption of various devices for the 

 purpose of lessening the damage. In May 1913 one person applied 

 burlap strips soaked in lubricating oil to a number of sugar maple 

 trees set some ten or eleven years before at Halt on. Mass. Those 

 bands were for the purpose of preventing caterpillars from ascending 

 the trees. The maples apparently leaved out normally the follow- 

 ing spring and the first observed injury was noted in August 1914 



