28 



not yet been concluded. Arsenate of lead has o:iven favorable results, 

 but whether it is because of killino; the insect or merely repelling it is 

 not known yet. Clean culture, however, is the best remedy. 



May beetles caused considerable damacye in former years, but in 

 groves which are now kept free from weeds they have almost disap- 

 peared. The greatest damage caused by these insects is by eating the 

 foliage; it is also universally believed that the larvae feed on the bark 

 of the roots. It is questionable whether much damage is caused in 

 that way, but unquestionable evidence has been found in a few 

 instances. 



The brown ant which was reported upon last year by the entomolo- 

 gist of this station is not causing much damage at present. It occa- 

 sionally eats the young foliage, which causes no severe injury to a 

 vigorous tree. It very seldom injures mature bark except close to the 

 ground. The injury there is caused by the ants building galleries of 

 earth upon the trunk for some distance, w^hich softens the bark under- 

 neath and makes it easy to puncture. The ants may live in those gal- 

 leries for some time wnthout puncturing the bark, but if left undis- 

 turbed for a long time they usually do so. The greatest damage is 

 caused to trees w^hich are affected with "gumming;" in fact, trees over 

 two or three years old are seldom seriously damaged unless affected 

 with that trouble. The remedy for ants is, in the first place, clean cul- 

 ture, by which means the nests are continually disturbed except close 

 to the tree. For killing all the ants in a nest, nothing is better than 

 carbon bisulphid, but that can not be used close to the tree, neither 

 can it be used successfully in loose soil except when the soil contains 

 enough moisture to make it impervious to the fumes. Any soap or 

 emulsion used for scale is also a successful remedy for ants. Whale- 

 oil soap or resin soap may be used as thick as it can be made to flow 

 through the galleries, and it can be made more effective by adding 

 crude carbolic acid at the rate of one part to ten of the soap solution. 

 This can be used close to the tree without injury. 



DISEASES. 



With our present knowledge this subject must be treated with 

 some caution, since many symptoms are ascribed to diseases which 

 as a matter of fact are caused by some physiological derangement. 



"Gumming" or "gum disease" occurs very frequently in some 

 groves. When appearing on the limbs or upper part of the trunk 

 it resembles psorosis, a disease known as "tears," from the fact that 

 the gimi often oozes through the bark in single drops. Wlien appear- 

 ing on the trunk above the collar roots it resembles foot rot or mal- 

 di-gomma in some respects, while it is wholly dissimilar in other 

 respects. The symptoms are exudation of gum, bark becoming 

 brown in spots, frequently extending all around the trunk, and a 



