332 AMERICAN HUSBANDRY. 



the earth, it is obliged to climb th" tree on which it 

 is to feed. In this state it resembles a grub. The 

 male has wings, but usuiijly ascends the tree in com- 

 pany with the female. The eggs are deposited on 

 the branches, and from these the worm which is so 

 destructive proceeds. When the period of change 

 to a chrysalis arrives, the worm descends to the 

 earth, generally by spinning a web, and, hiding be- 

 neath the surface, remains till the change is comple- 

 ted, and again emerges in another form to recom- 

 mence its ravages. As the insect, in the state of 

 chrysalis, is limited to the spread of the branches at 

 farthest, and in most cases is within a few feet of the 

 trunk, moving the earth or incorporating with it ash- 

 es, lime, or other ingredients destructive or disagree- 

 able to them, would seem to be likely to kill them 

 or drive them away. Bandages of tar, fish-oil, and 

 other matters have been recommended ; but the only 

 effectual remedy yet known is the expensive one of 

 encircling the tree with a lead trough filled with 

 oil, the space between the trough and the trunk 

 being closely packed with some substance* that will 

 prevent the passage of the worm. As the trough is 

 occasionally replenished with oil, a passage over it 

 is impossible, and, of course, all access to the tree 

 is cut off. The great length of time, however, in 

 which the grub or worm ascends to deposite its 

 eggs, reaching from November till June, renders the 

 prevention of the attacks of this worm more trouble- 

 some than that of any other. Whenever the ground 

 is thawed during the winter, the worm will be found 

 ascending ; and, after it has once obtained a lodg- 

 ment in the tree, all methods to expel it have been 

 ineffectual. 



