HISTORY OF ORGYIA LEUCOSTIGMA. 6g 



Saunders: in Canad. EntomoL, iii, 1871, p. 14, f. 10 (eggs aufi larva descr.); in 



Kept. Ent. Soc. Ont., for 1874, p. 19, figs. 14-16 (general notice); Ins. 



Inj. Fruits, 1883, pp. 57-60, figs. 50-53 (the several stages and remedies). 

 Bethune: in 1st Kept. Ent. Soc. Out., 1871, pp. 82-3, figs. 23, 24 (brief notice); in 



2d Kept. Id., 1872, p. 14 (abundance and injuries). 

 French: in Thomas' Kept. Ins. 111. (vii), 1878, pp. 185-186, figs. 36, 37 (general 



notice). 

 Forbes: 12th Kept. Ins. III., 1883, pp. 100-1, fig. 20 (brief notice). 

 Coleman: in Psyche, ii, 1882, pp. 164-166 (larval colorational differences). 

 Lintner: in Albany Evening .Journal for June 25, 26 and 28, 1883 ; in 37th Kept. 



N. Y. St. Mus. Nat. Hist., for 1883, pp. 50-52 (larva3 girdling twigs). 



In studying the history of our insect foes it not unfrequently occurs 

 that a species which had long been known to entomologists, without 

 having assumed such injurious habits as to give it place among our 

 serious pests, suddenly increases to such an extent and so extends the 

 range of its food-plants, as to become a conceded and permanent public 

 nuisance. 



Such an one is the Orgyia leucostigma, an insect broadly distributed 

 over the United States, from Maine to Geargia and westward to the 

 Rocky mountains. For many years it was known only as an occasional 

 depredator upon apple trees and rose bushes. In the year 1828, accord- 

 ing to Dr. Harris, the apple trees in portions of New England were in- 

 fested wath multitudes of the caterpillars, and subsequently, in the sum- 

 mers of 1848, 1849 and 1850, they extended their attack to many other 

 trees, nearly stripping the leaves from the horse chestnuts in Boston. 



It appears for a long time to have had but local distribution. Dr. Fitch, 

 writing of it in 1856, had never known it to be sufficiently multiplied in 

 the vicinity of his residence, Salem, Washington county, N. Y., to merit 

 any attention on account of its depredations. He had never met with 

 a half-dozen of the caterpillars in any one year, perhaps owing to the 

 locality being near the northern extreme of their geographical range, 

 until in the summer of 1855, when they were noticed as being unusually 

 common. 



As early as the year 1870 it had become abundant in Albany and 

 firmly established. It has annually reappeared, with perhaps three or 

 four exceptions, and made great havoc upon the foliage of both fruit and 

 shade trees. One of these exceptional years was in 1874, when but few 

 of the larvae were seen, and another in 1884, when these notes are being 

 revised for publication. In several other of our larger cities this insect 

 also became a public pest. In Philadelphia they were very abundant 

 in 1873, as appears in an article in the Popular Science MontMy, vol, 

 iv, page 381, entitled, "The Caterpillar Nuisance in Philadelphia," in 

 which a former pest [^Ennomos subsignaria], one of the measuring-worms 



