INSECT PESTS OF OHIO SHADE AND FOREST TREES 275 



exists for the establishment of new colonies. The experience at 

 Bratenahl is a striking example of the grave danger from this 

 source. 



Moreover, since automobile traffic is very heavy through New 

 England during June and July when the caterpillars are abundant, 

 this offers an excellent opportunity for the larvae to become widely 

 scattered. Floating driftwood likewise offers excellent oppor- 

 tunities for the transfer of the insect to points down stream from 

 the infested woodlands, particularly of egg masses. Other means 

 of dispersal are by birds, in the clothing and effects of travelers 

 and campers, etc., but by far the most important means are by wind 

 transference and by the winter shipment of outdoor objects, such 

 as lumber, stone fencing and other rough materials upon which the 

 eggs may have been deposited. 



Nature of work. The harm done by the gipsy moth in the 

 main consists in the destruction of the foliage by feeding larvae, 

 but in severe infestations an incidental effect consists in discomfort 

 caused by the caterpillars invading dwellings and in the unsight- 

 liness produced by the adults depositing their eggs on porches, 

 garden-furniture, etc. In severe infestations where artificial con- 

 trol measures are not used, the continued seasonal outbreaks of 

 the caterpillar cause the death of nearly all tree and shrub growth. 

 Thousands of acres of woodland have been destroyed in this way in 

 New England. A glance at Plate XLVI, Figs. 1 and 2 conveys the 

 impression better than words. 



Food plants. The gipsy moth caterpillars can subsist upon 

 practically every shrub and tree native to this country and in addi- 

 tion, may under stress attack herbaceous plants. Forbush and 

 Fernald (37) record more than 500 plants known to be eaten by this 

 species, and it is because of this cosmopolitan taste that the gipsy 

 moth is able to survive such a variety of conditions and to maintain 

 its high standing in the list of noxious pests. A decided preference 

 is shown for certain groups of plants and of the chosen sorts, the 

 oaks may be named first. 



Distribution. In Europe this insect is widely distributed, but 

 in America its distribution is limited in the main to the New Eng- 

 land states and nearby parts of Canada. Isolated outbreaks have 

 occurred in other parts of the eastern and east-central United 

 States. Fortunately due to the combined activity of the Federal 

 Bureau of Entomology and the authorities of the states involved, 

 these outbreaks have been subdued ; and it is to be hoped that noth- 

 ing will transpire to interfere with the admirable and efficient 

 services these organizations are rendering. 



