ELEMENTARY STUDIES IN IXSECT LIFE 



to defoliate his tree and to lessen the fruit crop thereon. 

 If lie desires to combat them at this time the labor is 

 much increased: the whole fork must be cut out, or else 

 the large web with its inhabitants must be brushed away. 

 1 5ut before this stage has been reached the horticul- 

 turist has already suffered a loss in foliage destroyed, 

 a loss which he cannot repair. The trees, if neglected, 

 are soon stripped of their foliage. The vital powers of 

 his fruit trees, then, are so greatly taxed that they 

 usually bear little or no fruit that season. 



Canker Worm. 1 As the horticulturist is at work among 

 his trees about the time the foliage begins to cast a 



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, 



*^^4 



FIG. 103. Parents of the spring canker worm : a, female ; b, male (Paleacrita 

 vernata). Drawn from nature, by Miss M. E. Wise. 



shadow, he frequently notes small caterpillars dropping 

 down by a thread from the disturbed branches of the 

 trees. A few days later he sees the same trees nearly 

 stripped of their leaves. If these caterpillars, swinging 

 in the air by their silken threads, do not alarm him, he 

 will soon be more emphatically impressed by the defoli- 

 ated trees. If, however, he is familiar with the life his- 



1 Paleacrita vernata is the scientific n;im<> lor spring canker worm. Another 

 species, Anisopteryx pometaria, appears usually in the fall. 



