15 



The species may be transported, too, in the egg stage. It has been 

 shown that the egg clusters are laid upon many different kinds of 

 objects. Cord wood stacked and piled may be carried away in the 

 autumn bearing many egg masses, and, if not burned before summer, 

 larvae ma}^ issue in a new localit3\ The same maj^ be said for lumber 

 piles near infested trees. Freight cars ma}^ have been sidetracked 

 near an infested place long enough to permit laying of the eggs upon 

 them. 



It is by these methods that the comparatively rapid spread of the 

 insect pr-eviously noticed, during the years 1900-1906, is to be 

 explained. 



DAMAGE TO PLANTS. 



The larva of the gipsv moth feeds upon the foliage of practically 

 all orchard trees, all shade and ornamental trees, all out-of-door shrubs, 

 and all forest trees. ]Not on\y are the deciduous forest trees stripped, 

 but the coniferous trees as well. In June and July patches of forests 

 in the infested territory are stripped of every green leaf and the trees 

 appear as bare as in winter. After several such consecutive strip- 

 pings, deciduous forest and shade trees are killed, but with a coniferous 

 tree, such as a pine, hemlock, or .spruce, one complete stripping will 

 cause death. It is this fact which makes the gipsj" moth so much more 

 serious a pest than the brown-tail moth, and the loss which will result 

 from its spread into northern New England will be very great, owing 

 to the enormous coniferous forest interests in that part of the countr3\ 



In cities and towns the insect does damage not only by destroying 

 all vegetation, but by swarming in numbers upon and about houses, 

 frequently entering them. It has been the experience in eastern 

 Massachusetts that where a locality becomes thoroughlj^ infested the 

 value of real estate rapidl}^ depreciates, and it becomes a matter of 

 difficulty to rent or sell propertj'. 



Among its food plants the gipsy moth caterpillar seems to prefer 

 apple, white oak, red oak, willow, and elm, but those who have studied 

 it most carefully in Massachusetts say that it will on occasion devour 

 almost every useful grass, plant, flower, shrub, vine, bush, garden, or 

 field crop that grows in the State. 



NATURAL ENEMIES AND PARASITES. 



Observations extending over a number of years show that birds have 

 some importance as enemies of the gipsy moth. As already suggested, 

 the fact that the insects spread comparatively slowly in the vicinity of 

 Medford between the 3^ ears 1869 and 1889 is probably to be accounted 

 for in part by the fact that insectivorous birds were much more numer- 

 ous in that part of Massachusetts during that period than they have 



275 



