18 BULLETIN 1223, U. S. DEPARTMENT OF AGRICULTURE. 



trees is not as great as in the West. This insect infests only elms, 

 doing damage particularly to young trees, but killing twigs and 

 branches of the older ones. It causes the leaves to turn yellow and 

 drop early, besides making foliage and ground black and sticky 

 from its secretion of honeydew. 



The first-stage larva is a small, yellowish, oval object about 0.5 

 millimeters long. The second-stage larva is over twice as long 

 as the first, and is reddish brown, but appearing gray from the 

 waxy coat on its back. The adult female is large and oval, about 

 2 millimeters long, and of a dull red-brown or green-brown color, 

 surrounded by a white cottony fringe of wax. 



The second-stage larvae hibernate in the bark crevices and about 

 the winter buds. In early spring the male larvae form cocoons 

 and transform in them to adults. By this time the female larvae 

 have molted and seek a sheltered place on the underside of the limbs 

 and branches. After mating they form a waxy fringe about their 

 bodies and in late spring or early summer begin to deposit their 

 eggs. This they continue to do throughout the summer, and upon 

 completing oviposition they shrivel and die. The larvae hatch very 

 soon from these eggs and crawl to the midribs of the leaves or in 

 some case remain in the bark crevices. All molt to the second stage. 

 Those on the leaves move in the fall to more premanent winter 

 quarters on the twigs and about the buds, where they remain until 

 activity begins again in the early spring. 



Several, lady-beetles feed upon the European elm scale but are 

 not plentiful enough to be considered as important enemies. A num- 

 ber of sprays have been experimented with, but only washing in 

 the spring with a solid stream of water and spraying in the winter 

 with a solution of 23° to 28° Baume miscible oil, 1 part oil to 12 parts 

 water, have proved effective in the control of this pest. 



LITERATURE CITED. 



(1) Cooley, R. A. 



1898. Notes on some Massachusetts Coccidae. In U. S. Dept. Agr., Div. 

 Ent. Bui. 17, n. s., p. 61-65. 



(2) Craw, Alexander. 



1894. Entomology and quarantine. In 4th Bienn. Rept. Sta. Bd. Hort. 

 Calif., 1893-1894, p. 79-109, pi. 37-38, figs. 



(3) Doten, Samuel B. 



1908. The European elm scale. Nevada Agr. Exp. Sta. Bui. 65. 34 p., 

 14 pi. 



(4) 



1910. Spraying trees for the elm scale. Nevada Agr. Exp. Sta. Circ. 6. 

 6 p., 3 fig. 



(5) 



1912. The European elm scale. In Mo. Bui. Calif. Sta. Comm. Hort., 

 v. 1, no. 3, p. 89-100, fig. 28-37. 



(6) Essio, E. O. 



1915. Injurious and beneficial insects of California, Suppl. Mo. Bui. 

 Calif. Sta. Hort. Comm. 541 (+lxxxi) p., 503 fig. 



(7) Felt. Ephraim Porter. 



1905. Elm bark louse. N. Y. State Mus. Mem. 8, p. 203-207. Bibliog- 

 raphy, p. 207. 



(8) Hartzell, Albert. 



1921. Distribution of the European elm scale. In Proc. Iowa Acad. 

 Sci. for 1921, v. 28, p. 201-205, fig. 31. 



