58 BULLETIN 286 



February, moistened and placed by the stove, hatched and the cater- 

 pillars, which were fed on leaves of Abutilon, apparently throve finely 

 but were not reared to maturity. Other eggs from Arena placed out- 

 doors under natural conditions hatched at Ithaca as early as April 23rd. 



The number of eggs that may be deposited on a single tree is very 

 great. The number in six average clusters ran as follows: 93, 21, 44, 

 40, 89, and 67, respectively. Many clusters contain more eggs than 

 the highest of the foregoing. Scores of such egg clusters exist on many 

 of the trees in the infested area. Messrs. Graef and Weibe say that 

 they removed at least 60,000 eggs from one small maple tree in Brooklyn. 



It is probably right to say that the eggs of this moth begin to hatch 

 in the latter half of April, and in high altitudes probably not much 

 before the middle of May. When a caterpillar first emerges from the 

 egg it is only about one-tenth of an inch in length and its general color 

 is green. The head, last abdominal segment, and sides of the body 

 are light green while the back is a darker green. In general, when 

 the larva is viewed from above, the two ends of the body appear light 

 green in color with the part between a darker olive green. 



The young larvae begin at once to eat the green tender leaves. 

 On May 3d, the writer placed six caterpillars, just out of the egg, on 

 fresh tender maple leaves, each caterpillar on a leaf by itself, to watch 

 its habits of eating. By the morning of May 5th each one had eaten 

 holes through its leaf, varying from pinholes up to good sized shot 

 holes. In one leaf eighteen such holes had been eaten, which shows 

 something of the voracity of the tiny larvae. Observers who have 

 had the opportunity to watch these larvae in the forest say that at 

 first they climb to the top of the tree and to the ends of the branches 

 where the leaves are presumably younger and more tender. As they 

 grow they gradually ravage the entire tree. 



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 larvae 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. The six larvae reared on separate maple leaves and receiving an 

 abundance of food were without exception of a beautiful pale rose 

 color with three distinct tubercles on the abdomen, as shown in Figs. 

 54, 55. Many of the caterpillars received from the infested forest trees 

 were of a light green color throughout and in marked contrast with 

 the darker ones. Full grown caterpillars that have had all the food 



