98 MASSACHUSETTS AGRICULTURE. 



among those that appear in the autumn and winter, and that 

 the males are most abundant in the spring. The sluggish 

 females instinctively make their way towards the nearest trees, 

 and creep slowly up their trunks. In a few days afterwards 

 they are followed by their winged and active males, which flut- 

 ter about and accompany them in their ascent, during which 

 the insects pair. Soon after this the females lay their eggs 

 upon the branches of the trees, placing them on their ends, 

 close together in rows, forming clusters of from sixty to one 

 hundred eggs or more, which is the number usually laid by 

 each female. The eggs are glued to each other and to the bark 

 by a grayish varnish, which is impervious to water. The eggs 

 are usually hatched between the first and the middle of May, or 

 about the time that the red currant is in blossom, and the young 

 leaves of the apple-tree begin to start from the bud and grow. 

 The little canker-worms, upon making their escape from the 

 eggs, gather upon the tender leaves, and, on the recurrence of 

 cold and wet weather, creep for shelter into the bosom of the 

 bud, or into the flowers, when the latter appear. 



" It should be stated that, where these insects prevail, they 

 are most abundant on apple and elm trees ; but that cherry, 

 plum and lime trees, and some other cvltivated and native trees, 

 as well as many shrubs, often suffer severely from their voracity. 

 The leaves first attacked will be found pierced with small holes ; 

 these become larger and more irregular when the canker-worms 

 increase in size, and at last the latter eat nearly all the pulpy 

 parts of the leaves, leaving little more than the midrib and 

 veins. When fully grown and well fed the caterpillars measure 

 nearly or quite one inch in length. They leave off eating when 

 about four weeks old, and begin to quit the trees ; some creep 

 down by the trunk, but great numbers let themselves down by 

 their threads from the branches, their instincts prompting them 

 to get to the ground by the most direct and easiest course. 

 After reaching the ground they immediately burrow in the 

 earth to the depth of from two to six inches, unless prevented 

 by weakness or the nature of the soil. In the ground they 

 make little cavities or cells by turning round repeatedly and 

 fastening the loose grains of earth about them with a few silken 

 threads. Within twenty-four hours afterwards they are changed 

 to chrysalids in their cells." 



