764 JOURNAL OF FORESTRY 



it to the ants, and report having found a red ant, Formica exsectoides 

 Forel, in more than sixty hills studied in this connection at Ansonia, 

 Middlebury, New Haven, Union, and other Connecticut localities, and 

 in Pike County, Pennsylvania; and in one a black ant, F. fusca var, 

 snhsericea Say, which, however, is stated to be a host species of F. ex- 

 sectoides. Occasionally ants were observed tending dark-colored aphids 

 on trees near the hills of F. exsectoides. The trees involved exhibited 

 a ". . . constriction of the trunk extending from i to 5 inches just 

 above the ground line with a decided swelling at the upper margin. 

 . . . 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 has 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. . . . Instances have been observed where 

 partially girdled trees have recovered." No outside evidences of gird- 

 ling were seen. The conclusions the authors reach are as follows : 



1. Ants are responsible for the damage. 



2. It is probably not due to a fungus. 



3. It is probably not due to mechanical injury, soil poisoning, nor 

 damage to the roots. 



4. It is to be combated by destroying the ants or by leaving unplanted 

 areas about the ant colonies. The species involved was mainly Pinns 

 strobus, but the following also were sometimes affected : Betula populi- 

 folia, Hicoria ovata, Juniperus virginiana, Pinus sylvestris, Populiis 

 tremuloides, Quercus nana, and Rhus hirta. 



In the spring of 19 15 the present writer was detailed to collect data 

 on this problem in connection with other work on the Portland State 

 Forest, Connecticut. It is through the kindness of Mr. Filley that this 

 material is here presented for what light it may shed on the problem. 



The following considerations presented themselves and were kept in 

 mind during the study : 



1. If this dying is due to a specific fungus (or group of fungi), it 

 may be carried by ants or otherwise. 



2. If carried by ants is it intentional or accidental ? 



3. Do the ants feed on the fungus or on the pine bark?^ 



4. Have ants been known previously to feed on fungi? 



5. Have ants been known previously to feed on pine bark? 



6. If ants carry the fungus incidentally, why do they visit the trees? 



• Cf. p. 10 and fig. 2. 



