686 



AAdERICAN FORESTRY 



75 per cent of all the trees had been killed. Since these 

 ants are common throughout the northeastern United 

 States, particularly on the class of lands ordinarily re- 

 forested, the importance of the danger is evident. 



In the case of white pines the injury is first mani- 

 fested by a slight yellowing of the foliage which grad- 

 ually increases until the tree dies and the leaves turn 

 brown. Examination of a dying or recently dead tree 

 shows a constriction of the trunk extending- from 1 to 



No. 1. No. 2. 



No. I. — Young white pine, near N'ew Haven, Connecticut, showing character- 

 istic constriction just above ground line which is indicated by the upper edge of 

 ruler. 



No. 2. — Young Scotch pine, near New Haven. Connecticut, killed near ant 

 hill, showing prominently the callus and increased growth above injury. 



5 inches just above the ground line and with a decided 

 swelling at the upper margin. Upon removal of the 

 bark, the cambium layer is found to be girdled as by a 

 canker, while the swelling above the injury is due to 

 callous and continued growth of the stem in diameter for 

 two years or so after growth below ceased. Above the 

 seat of principal injury is to be found a considerable 

 number of small depressions in the bark which extend 

 up the trunk from a few inches to two feet or more. 

 On living trees ants have frequently been observed about 

 fresh injuries to the green bark. These patches later 

 develop a corky layer and produce the characteristic dark 

 pits referred to above. Instances have been observed 

 where partially girdled trees have recovered. 

 The conclusions to be drawn are therefore: 

 1. The ants are responsible' for the death of the 

 trees, as in no instance has this particular trouble been 

 observed except in the immediate vicinity of ant colonies. 

 It appears to the advantage of the ants to kill vegetation 

 which otherwise would shade the colonies too much. The 

 damage is most noticeable in plantations presumably be- 

 cause ants are most abundant in open areas. 



'This conclusion is drawn in spite of the fact that ants have 

 not previously been considered enemies of trees. Heretofore they 

 have been classed as beneficial on account of destroying large 

 numbers of insects. 



2. The immediate cause of the death of the trees is 

 not yet understood. Dr. A. H. Graves - believed it to be 

 due to a fungus, but was unable to substantiate this be- 

 lief. Inoculation of healthy trees produced only negative 

 results. No fruiting bodies on the injured areas have 

 been observed by the writers, and the range of species at- 

 tacked seems too great for a single fungous disease. If 

 fungi or bacteria are responsible, the only plausible means 

 of dissemination is through the agency of the ants. There 

 is no evidence that the damage spreads from tree to tree. 



3. From the appearance of the specimens examined by 

 the writers, the death of the trees is not attributable to 

 mechanical injury to the bark from the biting of the 

 ants, as there are no evidences of girdling from the out- 

 side. That the trouble is not due to soil-poisoning or 

 damage to the roots is indicated by the nature of the 

 injury and its localization. 



4. The only ajiparent means of combating the trou- 

 ble is to destroy the ant colonies. Experiments are now 

 in progress to determine the best means of accomplishing 

 this. Carbon disulphide and naphthalene flakes may 

 prove efficacious if properly administered. In order to 

 avoid loss of young trees, the work of extermination 

 should be done prior to planting. Otherwise it is ad- 

 visable to leave unplanted a circle at least 20 feet in radius 

 about each colony of Formica exsectoides. 



DOUGLAS RODMAN DEAD 



Douglas Rodman, a well-known forester, died sud- 

 denly of heart failure in Butte, Montana, on July 6th 

 and was buried at Frankfort, Kentucky, the city where he 

 was bom on March 22, 1882. After preparatory schooling 

 in Kentucky, he studied under Dr. Schenck at Biltmore, 

 graduated there and entered the Forest Ser\'ice. His 

 first detail was to Manitou Islands, after which Mr. 

 Pinchot sent him as ranger to the Gila Forest Reserve in 

 New Mexico. Here his energy and ability were soon 

 recognized. He was made assistant forester and then chief 

 forester over this difficult and large reserve, and finally 

 succeeded to such an extent as to secure Mr. Pinchot's 

 high commendation. Mr. Rodman resigned from the 

 Forest Service to make general forestry and mining in- 

 vestigations in the Pacific Coast states and Alaska. He 

 was for several years in charge of forest engineering for 

 the C. A. Smith Company at Marshfield, Oregon, intro- 

 ducing scientific forestry into this large operation. Mr. 

 Rodman was a man of high enthusiasms and warm friend- 

 ships. In his wide traveling and experience he made many 

 friends over the country who will grieve at his death 

 while still in his active years. 



THIRTY-SEVENTH ANNUAL MEETING 

 The 37th annual meeting of the American Forestry 

 Association will be held at Washington, D. C, on 

 Thursday and Friday, January 18 and 19, 1917- All 

 members are urged to attend. The program will be 

 announced later. 



'A preliminary note on a new bark disease of the white pine 

 Mycologia, vol. vi. No. 2, March, 1914. 



