THE SNOW-WHITE LINDEN MOTH 



Ennomos subsignarius Hiibn. 

 Order, Lepidoptera; superfamily, Geometrina 



A half century ago the snow-white linden moth was a conspicuous 

 insect in some of our Eastern cities and its caterpillars were very abun- 

 dant and exceedingly injurious to shade-trees. From 1857 to 1870 

 the shade-trees of Brooklyn, N. Y., and Philadelphia, Pa., were annually 

 subjected to defoliation by this insect. To check its increase, the Eng- 

 lish sparrow was introduced from Europe, and so well did this bird 

 do its work that for nearly a half century we have heard almost nothing 

 about this insect as a shade-tree pest. During this time there has been 

 an occasional reference to it as a forest-tree despoiler, but it was not 

 until 1907 that it again appeared as a serious pest, in New York State 

 at least. During that year it seriously injured forests in the Catskills 

 and the Adirondacks. In 1908 and 1909 it was again very abundant 

 and seriously injurious, and now in 1910 it promises to be as prevalent 

 as ever. During the last two years, in rearing large numbers of the 

 moths the writer has been able to find but one single specimen of a 

 parasite. It may be that the absence of parasites is the main reason 

 for the great abundance of this insect. At any rate, we must conclude 

 that the environments, climatic conditions, and other factors have been 

 especially favorable for this insect during the past four or five years. 

 Just how long it will continue in its present abundance, how widely it 

 will spread, and whether it will eventually become a pest .to our fruit- 

 trees and ornamental plants, are questions the answers to which we 

 shall await with much interest and considerable anxiety. 



THE NAME 



This insect has masqueraded under several names during its career 

 with the scientists. It was first named in 1806 by Hiibner, who called 

 it Eudalimia subsignaria. About a half century afterward, T. W. 

 Harris, in a paper in Hovey's Magazine of Horticulture, says, "This 

 species not having been scientifically described or named before may 

 be called Geometra niveoser ice aria, the snow-white silky Geometer." 

 In 1857, Guenee placed it in the genus Ennomos. Four years later, 

 Mr. J. B. Jones, in a communication to the Entomological Society of 

 Philadelphia, referred to it as Geometra niveosericearia, and also gave it 



