Apple. 



251 



FIG. 42. Canker 

 worm moth; male, 

 natural size. 



rid of the pest is to spray the foliage with Paris green or Lon- 

 don purple. 1 This should be done early in the season, as soon 

 as the caterpillars make their appearance. If they are seen to 

 be injuring the trees before the blossoms are 

 open, it may be well to make an application 

 at that time. But generally it is not neces- 

 sary to spray the trees till after the blossoms 

 have fallen. Never apply the arsenites to 

 fruit trees while they are in blossom, for the 

 bees which are working among the flowers 

 and assisting in the setting of the fruit may 

 be poisoned, to the loss of their owner as 

 well as to the owner of the orchard. Whether 

 bees are actually poisoned by arsenites when 

 applied to trees while in full bloom is still a 

 disputed point ; 2 they probably are, and the grower will do well 

 to apply sprays either before or after the trees have bloomed. 

 It may also be that the injury done to the delicate parts of the 

 flower by the materials used is alone sufficient cause for avoid- 

 ing this time to do the work. The time of blossoming is short, 

 and trees should not suffer if sprays are properly applied before 

 and after this period. 



If one application of the arsenite is not effective in ridding 

 the trees of worms, others should be made at intervals of eight 

 or ten days until the pest is overcome. When the worms are 

 young, they most commonly feed upon the 

 under side of the leaves, and it is a good plan 

 to treat these parts thoroughly. In making 

 the applications it must be remembered that 

 the worms will not be destroyed unless the 

 poison is placed upon the leaves. All parts 

 of the tree should be drenched, and if many 

 worms remain a few days after such an appli- 

 cation, the materials used are faulty, or they 

 have not been mixed in the proper proportions. 



Cigar-case-bearer; Case-worm (Coleophora Fletcherella, Fer- 

 nald). Description. The appearance of this insect is so 



1 See Bailey, Cornell Ayric. Exp. Sta. 1895, Bull. 101. 



2 Cook, Mich. Agric. Exp. Sta. 2d Eep. 261. Webster, Insect Life, Vol. v. 

 No. 2, 121. Lintner, Hid. Vol. vi. No. 2, 181. 



FIG. 48. Canker- 

 worm ; adult fe- 

 male, natural size. 



