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MASS. EXPERIMENT STATION BULLETIN 353 



Severe local defoliations by this insect sometimes occur at irregular intervals, 

 following which there are periods of practically no damage due chiefly to the 

 activity of the predators and parasites of the insect. Insectivorous birds and 

 bacterial diseases also take their toll. 



Description. The female moth is light gray in color, wingless except for small 

 rudimentary stubs, and has simple, threadlike antennae. The male moth is 

 grayish-brown, has normal wings with a spread of about IJ^ inches, and has large, 

 ieathery antennae. 



The individual eggs are almost round, about 1/25 inch in diameter, and white 

 or yellowish in color with a light brown spot surrounded by a ring of the same 

 color. They are laid in masses of 100 to 700 on the empty cocoons of the female 

 and covered with a white frothy material which soon hardens and becomes brittle, 

 thus forming an effective protection. 



White-Marked Tussock Moth. 



Caterpillar. (Note two pencils of hair forward and one at rear.) 



Courtesy, N. H. Agr. Expt. Station. 

 Cocoons on branch of a tree. 

 Wingless adult laying eggs on cocoon. Slightly enlarged. 



Figs. 2 and 3, Courtesy Mich. Agr. Expt. Station. 



Slightly enlarged. 



