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MASS. EXPERIMENT STATION BULLETIN 353 



Birch Skeletonizer 



1. Vacant mine of larva in birch leaf. 4X. 



2. Fully grown larva with first (lower) and second (upper) vacant molting webs on birch 

 leaf. 4X. Figs. 1 and 2. Courtesy, Conn. Agr, Expt. Station. 



3. Birch leaf skeletonized by larvae, showing webs and the ribbed cocoons. Enlarged. 

 Courtesy, Mich. Agr. Expt. Station. 



The eggs are laid singly and scattered over the leaf. They are translucent 

 white when first laid but soon become quite opaque, are flatly ovoid in shape 

 and about 1/100 inch in diameter. They are encircled by an adhesive substance 

 which attaches them to the leaf surface. 



The newly hatched larva, or caterpillar, which mines in the tissues of the leaf, 

 is very tiny. It is translucent, flattened, and legless — a typical leaf-mining 



