294 INSECTS AFFECTING VEGETATION 



The larva pupate under the surface of the soil, the pupa proper 

 being reddish brown, and somewhat smaller than that of the tobacco 

 sphinx. It also lacks the peculiar "jug handle" common to the 

 other species. Tjie moth is of the regular sphinx type; pointed 

 body, narrow, strong wings, large eyes, and is of a gray ashy color. 

 The eggs are deposited in pearly masses on the under sides of the 

 leaves. The winter is passed in the pupal stage. 



Three methods of control are practicable to be used against the 

 pest. The first is collecting the egg-masses or clusters of newly 

 hatched larva?. The second method is spraying with arsenicals. 

 The third relates to the control of the species in nurseries or planta- 

 tions and consists in deep plowing at the time the insects are in the 

 pupal stage. 



The Snow-White Linden Moth. The moths are pure white, 

 and the females are somewhat larger than the males and have 

 thread-like antenna?, while the males possess feather-like antenna?. 

 The front wings of the male and the female are angulated, those of 

 the female more prominently. The eggs of the female moth are 

 laid on the under sides of the branches as often on the upper 

 branches of the smaller trees, at least, as on the lower. The eggs 

 are deposited on the branches in the latter part of June and first 

 part of July, and remain unaffected by snow, rain, or extremes of 

 temperature until the following April and May, nearly a year after 

 deposition. 



The eggs are about one twenty-fifth of an inch in length, barrel 

 shaped, often more or less flattened on the sides, light olive when 

 first deposited but later becoming darker in color, with a conspicu- 

 ous ring at the free extremity. They occur in irregular masses, 

 long and narrow if the branch is small but spread out if the surface 

 is large. 



The caterpillars vary considerably in color and markings. In 

 general, after the first molt they become dark reddish brown, in 

 many cases almost black, with the head and last abdominal segment 

 red or reddish brown and quite conspicuous. The larva? resemble 

 the twigs of the tree on which they are feeding, and like other 

 "measuring worms" have the habit of holding themselves erect and 

 motionless like a broken twig. Full grown caterpillars that have 

 had all the food they want become a little over two inches in length, 

 but when they are crowded and the food supply limited they are 

 often less than two inches long. During their growth the larva? 

 molt five times or even six times. The cocoons are very flimsy af- 

 fairs and usually are made by turning over the edge of a ragged 

 leaf and lining the inside with a thin net-like layer of silk. The 

 larva? infest a great variety of forest-trees, apparently somewhat pre- 

 ferring beech and maple. They have been found on elm, linden, 

 chestnut, hickory, ash, apple, birch, and others. 



The insect requires nearly a year to pass through its life his- 

 tory. In the control of this pest in shade-trees, spraying with arsen- 

 ate of lead, 3 pounds to 50 gallons of water, would probably be very, 

 effective. If it ever becomes injurious to apple trees in this State, 



