864 



AMERICAN FORESTRY 



A. Replying to your inquiry about the effect of locust 

 trees in supi)lying nitrogen to crops grown amongst the 

 trees or after them, I will say that I know of no definite 

 investigations of this kind but I have seen many instances 

 of marked effect of this kind. I remember the last time 

 I was at Montgomery, Ala., I went out to visit a plan- 

 tation. There was a row of locusts through a large field 

 in which the cotton looked like it might produce a bale 

 or more to the acre. This strip was about ten feet wide, 

 shading off till at a distance of about 25 or 30 feet from 

 the center of the row the effect was no longer visible. 

 Outside of this strip the cotton would not produce more 

 than a quarter of a bale to the acre. The appearance of 

 the strip was so noticeable that I inquired as to the cause. 

 The owner of the plantation 

 said: "That is where I used 

 to have a row of locust 

 trees ; they always do that." 

 This is a typical instance of 

 several similar ones I have 

 seen. 



I may add that Mr. O. F. 

 Cook, of this Bureau, who 

 has given a good deal of 

 attention to tropical agri- 

 culture, has observed that 

 in coffee plantations it is a 

 common practice to allow 

 certain leguminous trees to 

 grow here and there. The 

 planters formerly attributed 

 the favorable effect of these 

 trees to their shade, but they 

 had noticed it was the shade 

 of only particular kinds of 

 trees that had the effect. It 

 was observed that in every 

 case the trees favored by 

 the planter belonged to the 

 leguminosae family. 



These instances lead me 

 to believe that locust trees 

 do have an important effect 

 in supplying nitrogen to 

 nearby crops or to crops 



which follow. W. J. Sl'ILLM.\N, 



In Charge Office of Farm Management, Bureau of 

 Plant Industry, Washington, D. C. 



Q. We set out in Century, Fla., during the past eight 

 years some sixty to seventy-five water oaks for shade 

 trees and these trees have been doing nicely up to the 

 last year or two, but we now find quite a few of them 

 suffering from some kind of a Borer, .some insect that 

 works its way around under the bark, sometimes making 

 a circular path 15 inches long, or even longer than this, 

 then, at apparently about the beginning of spring, vvork.'5 

 its way into the very heart of the tree, thence up to the 



Twigs, 



biuis and base of leaves 

 injured by 



heart for a few inches, thereby causing the trees to bleed 

 or lose sap. 



The insect in question makes a hole in the tree, as it 

 bores into the heart, about one-half inch in diameter, 

 and the i)ath that it makes around under the bark before 

 starting into the heart varies from 1 inch wide to as wide 

 as a man's hand. 



These trees are native of this country and the young 

 trees were gathered from adjoining lands. 



We will thank you for any information as to how to 

 handle or control this pest and any suggestions you can 

 make us will be gratefully received. 



Alger-Sullivan Limber Company. 



Century, Fla. 

 A. In reply it is quite 

 necessary as a basis for giv- 

 ing you the desired infor- 

 mation that we should have 

 specimens of the borer or 

 of the bark and wood show- 

 ing the character of its 

 work. The description in- 

 dicates that two or more 

 species of insects may be 

 involved, one with the bark- 

 boring habit, the other a 

 bark and wood borer. 

 Specimens of work should 

 show injury to living tissue. 

 If you will supply the 

 specimens we will take pleas- 

 ure in giving you informa- 

 tion about the insects and 

 methods of combating them. 



A. D. Hopkins, 

 In Charge of Forest Insect 

 Investigations, Washing- 

 ton, D. C. 



ADVICE FOR THE MONTH OF 

 AUGUST 



1. Continue cultivating 

 and watering the newly 

 planted trees and shrubs 

 and those that are weak. 



2. Spray for aphis. Beech, white pine, fruit trees and 

 elms are at this time commonly attacked by various spe- 

 cies of soft-bodied, sucking insects and the treatment in 

 each case, this month, is about the same spraying with 

 whale oil soap, one pound to 5 gallons of water. 



3. Destroy the pupae of the elm leaf beetle. The elm 

 leaf beetle has the peculiar habit of descending from the 

 branches to the base of the tree in grub form and there 

 changing into pupa form. This happens during the first 

 week in August and those who are acquainted with this 

 remarkable feature of the life history of the beetle take 

 advantage of the opportunity to collect or destroy the 

 pupae when they lie in masses at the base of the tree. 



of hickory trees which have been 

 the hickory bark beetle. 



