178 NORTH AMERICAN INSECTS. 



These troughs ought not to be nailed to the trees, but 

 should be supported by a few wooden wedges driven be- 

 tween them and the trunks. A stuffing of cotton, cloth, or 

 tow should never be used; sea-weed and fine hay, which 

 will not absorb the oil, are much better. Before the troughs 

 are fastened and filled, the body of the tree should be well 

 coated with clay, paint, or whitewash, to absorb the oil 

 that may fall upon it. Care should be taken to renew the 

 oil as often as it escapes, or becomes filled with the insects. 

 These troughs will be found more economical and less trou- 

 blesome than the application of tar, and may safely be rec- 

 ommended and employed if proper attention is given to the 

 precautions above named. Some persons fasten similar 

 troughs, to contain oil, around the outer sides of an open 

 box, inclosing the base of the tree, and a projecting ledge is 

 nailed on the edge of the box to shed the rain : by this con- 

 trivance all danger of hurting the tree with the. oil is en- 

 tirely avoided." 



In the Manchester Guardian, an English newspaper, of the 

 4th of November, 1846, is the following article on the use 

 of melted India rubber to prevent insects from climbing up 

 the trees: "At the late meeting of the Entomological So- 

 ciety of London, Mr. J. H. Fennel communicated the fol- 

 lowing successful mode of preventing insects ascending the 

 trunks of fruit trees : Let a piece of India rubber be burned 

 over a gallipot, into which it will gradually drop in the 

 condition of a viscid juice, which state, it appears, it will 

 always retain; for Mr. Fennel has at the present time 

 some which has been melted for upward of a year, and has 

 been exposed to all weathers without undergoing the slight- 

 est change. Having melted the India rubber, let a piece 

 of cord or worsted be smeared with it, and then tied sev- 

 eral times around the trunk. This melted substance is so 

 very sticky that the insects will be prevented, and can be 

 captured, in their attempts to pass over it. About three 



