190 TRANSACTIONS OF THE ILLINOIS 



shaped, attenuated in front and somewhat more abruptly lessened behind ; 

 the body is marked with transverse ridges. When not extended, its length 

 is only about one-fourth of an inch. A third enemy is a minute lady-bird, 

 only about one-twentieth of an inch long, and of a deep brown color on 

 the wing-cases, the thorax being of a lighter color ; its scientific name is 

 Scymrues cervicalis, Muls. So far as observed, this species has only 

 attacked those lice found on the trunks and branches or at the surface of 

 the ground. I have also noticed a mite very often in the vicinity of the 

 colonies under circumstances which led me to believe they preyed upon 

 these insects, but have not attempted as yet to determine the species. 



Remedies. — When a tree ceases to grow with its usual vigor, its leaves 

 becoming paler and more of a yellow hue than" customary, and there is 

 no apparent cause for this decline, it will then be well to examine the 

 roots, to see whether or not they are infested by this louse. If found, 

 some one of the following methods of destroying them may be adopted : 



First, Dr. Fitch's, which is to clear away the earth from the roots as 

 far as it can conveniently be done, and pour strong soap-suds upon them 

 in sufficient quantity to penetrate and saturate the crevices in the excres- 

 cences. The soil taken out should be removed and other soil substituted, 

 or, if returned to its place, ashes should be freely mingled with it. In the 

 nursery, when transplanting or lifting the young trees, if a careful exam- 

 ination, which should always be made, shows any signs of the lice on the 

 roots, they should be dipped in strong soap-suds, which will generally 

 effectually destroy them. 



Another method, which was long ago practiced by French horticul- 

 turists, and strongly recommended by Blot in his celebrated essay on this 

 species, and which has also been recommended in this country by Harris, 

 Walsh and Riley, is to drench the roots of the infested trees with hot 

 water; applying a sufficient quantity to penetrate to all parts of the roots 

 which are attacked. Riley remarks that mulching around the infested 

 trees has been found, by Mr. A. E. Riehl and others, of Alton, to have 

 the effect of bringing the root-lice to the surface of the ground, thus 

 rendering them more easily reached by the water. That mulching or 

 surrounding the collar with rubbish has a tendency to collect these insects 

 at this point is certainly true, at least such appears to be the case so far as 

 my observations have extended, but whether these are from the trunk or 

 roots is a point I have not determined. It was on this account that I 

 recommended mixing ashes or lime with the mulching immediately around 

 the tree. 



As to the lice on the trunk and branches, Harris mentions the fol- 

 lowing methods of destroying them : 



Melted resin, mixed with an equal quantity of fish oil, put on the 

 infested spots, while warm, with a painter's brush. Removing the old 

 and rugged bark and scrubbing the trunk and branches with a stiff brush. 

 Applications of the spirits of tar, turpentine, urine, kerosene, soft soap, 

 and other similar substances, have been recommended. 



The same author suggests the following method, which requires too 

 much time and trouble, except now and then in case of a very valuable 



