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begun. Their general time of rising is in the spring, beginning about the 

 middle of March, but sometimes before and sometimes after this time ; and 

 they continue to come forth for the space of about three weeks. It has been 

 observed that there are more females than males 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 flutter 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 ten- 

 der 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 

 cultivated 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." 



In the chrysalis form they remain until they appear above 

 the surface of the earth as moths, when ascending the trees 

 they deposit their eggs and die, their progeny replacing them 

 in their numbers and devastations. Dr. Harris farther con- 

 tinues : — 



" As the females are destitute of wings, they are not able to wander far 

 from the trees upon which they have lived in the caterpillar state. Canker- 

 worms are therefore naturally confined to a very limited space, from which 

 they spread year after year. Accident, however, will often carry them far 

 from their native haunts, and in this way, probably, they have extended to 

 places remote from each other. Where they have Ijecome established, and 

 have been neglected, their ravages are often very great. In the earlj'- part 

 of the season the canker-worms do not attract much attention ; but it is in 

 June, when they become extremely voracious, that the mischief they have 

 done is rendered apparent, when we have before us the melancholy sight of 

 the foliage of our fruit-trees and of our noble elms reduced to withei'ed and 

 lifeless shreds, and whole orchards looking as if they had been suddenly 

 scorched with fire." 



