ISO 



InseEls and Diseases. 



numerous, the small webs it makes, added to the destruction of the 

 foliage, give the tree the appearance of having been scorched. The 

 remedies consist in various contrivances to prevent the female 

 insects ascending the tree. One mode is to encircle the trunk 

 with a canvass belt, coated with a mixture of tar and train oil 

 The mixture needs repeatedly renewing. Applying the tar directly 

 to the bark endangers the life of the tree. Dennis's lead troughs, 

 filled with oil, have proved effectual. Circular strips of zinc, about 

 four inches wide, passing around the trunk of the tree, the lower 



Section. 



Fig. 181. 



Fig. 182. 



edges standing out, as shown in Fig. 182, prove the most efficient 

 remedy, as the insects cannot pass the lower rim. Sheet iron will 

 not answer, as they cling to the rusty edge. 



The Peach-ivorjn or grub (^Egeria exitiosa, Trochilium exitio- 

 sum, of later authors) cuts into the bark (never far into the wood), 

 just below the surface of the ground. It attacks the peach, necta- 

 rine, and apricot. Its presence is indicated by the exudation of gum 

 at the root, mixed with excrementitious matter resembling sawdust. 

 It is very easily destroyed by scraping away the earth at the foot of 

 the trunk, and following the worm to the end of its hole with a knife, 

 beneath the thin shell of bark, under cover of which it extends its 

 depredations. If an orchard is thus examined once in spring and 

 once in early summer, few will escape. But to exclude the insect, 

 as a means of prevention, heap around each tree a small mound of 

 air-slaked lime or ashes, coal ashes, or even earth, in spring, allow- 

 ing it to remain till autumn. Encasing the foot of the tree with 

 pasteboard, or with stout oiled or painted paper during the summer, 

 effectually prevents the deposit of eggs in the bark. 



The perfect insect of the peach-worm, Figs. 183 and 184, is a 

 four-winged moth, resembling in form a wasp, but totally distinct, and 

 hi its character and habits closely allied to the butterfly and miller. 



