Sec. 12.] ENTOMOLOGICAL. 225 



American potash, and the same quantity each of flour of sulpliur and soap, 

 in 13 pints of water, is most excellent and efficacious in destroying insects. 

 If it requires to be stronger, the quantity of potash and sulphur may be 

 doubled, but the soap must remain the same. Upon immersion, tiio insects 

 — ants, caterpillars, cockchafers, grubs, etc. — are instantly killed, while the 

 solution occasions no injury to plants. The liquid will destroy ants and 

 grubs when poured into their places of resort. 



Preventive of Canker- Worms from Apple-Trees. — A letter from Maiden, 

 Mass., gives a most sensible plan for a cheap preventive of canker-worms, 

 which climb the boles of apple-trees : 



"Take pine boards of suitable width for four to box a tree. Cut them in 

 pieces two feet long on one edge, and four feet long on the other edge. Nail 

 them together in a box around the tree, with four sharp points up. This box 

 is to be adjusted about the tree before the grubs come from the ground, and 

 a peck of powdered lime or ashes thrown between the trunk of the tree and 

 the inside of the box. The caustic lime or ashes will destroy the grubs near 

 the tree, and the boxes will invite all the grubs near them to ascend and de- 

 posit their eggs. I found the pinnacles covered with grubs and eggs, and 

 the insects apparently contented with this highest point as a safe place, and 

 there the eggs were deposited. I then removed the boxes to a considerable 

 distance from the trees, and heard no more from canker-worms ; they all died 

 for want of proper food." 



Another plan, lately patented, to prevent worms climbing trees, looks as 

 though it would be effectual. A tin trough is made in two parts, large 

 enough to encircle the tree and leave a space four or five inches between tiio 

 trough and bole of the tree. From the outside edge of the trough a strip 

 of cloth extends all around, wide enough to have its upper edge tacked to 

 the tree, by whicii the trough filled with oil is sheltered from rain and sus- 

 tained in its place, so that worms creeping upward come first in contact with 

 the cloth, and if they crawl down that to get around the edge and so up the 

 tree, they are caught in the oil, which, being sheltered, remains in good con- 

 dition longer than when exposed. Now it is an experiment worth trying, 

 and for which there is no patent, whether a strip of cloth nailed around the 

 tree at one edge, and having the other extended six inches from the bole by 

 a wire or limber rod, would not answer the purpose without the oil-trough. 

 The under side of the cloth could be coated with some kind of pitch that 

 would not harden soon, being protected from sun and rain, whicli would 

 effectually prevent the ascension of insects — certainly much more so than 

 the belt of tar as it is usually applied. 



Dr. Tkimblk, in answer to the (juestion. what remedy to apply to this pest, 

 said that the only remedy is the ichneumon ])arasitcs. These, in their proper 

 time, will attack the worms and destroy them. In the mean time, while 

 one section of the country is ravaged, another is extraordinarily fruitful. 



He introduced specimens of the caterpillar that preys upon the grapevine, 

 to show that it has its parasite, one of which had just emerged from the 



