36 



Three of the four trees girdled on May 29 were infested by large numbers of 

 Dendroctonus on June 19, but there were many other apparently healthy trees 

 which were also attacked. At this date no newlj T infested trees were noticed that 

 were more than 50 feet away from the source of infection. Later the infestation 

 extended farther, but still it appeared that the trouble spread but slightly beyond 

 the limits of the half acre. Among the trees lightly attacked in 1899 only 1 was 

 reattacked and killed this year. Indeed, it seems that if a tree recovers from the 

 first attack it usually escapes the next year. Numerous examples of this have been 

 observed. 



Of the 34 trees noted on the one-half acre, 7 had been dead from one to three 

 years; 4 ungirdled living trees were attacked in June of this year; 4 were not 

 attacked in June, but were infested in October. Of the 4 girdled trees the 2 that 

 were hack-girdled and the 1 tl at was belt-girdled were infested and died, while 

 the 1 that was girdled to the heartwood died without the aid of Dendroctonus. 

 Two trees attacked last year recovered and were not attacked this. Two attacked 

 last year died this. Eleven trees were not attacked. 



The 9 trees that were dead on June 19 averaged 19.3 inches in diameter. The 8 

 ungirdled trees that were attacked this year averaged 15.7 inches in diameter. 

 The 3 girdled trees that died averaged 16.7 inches in diameter. The 13 trees that 

 were not attacked averaged 14.2 inches in diameter. 



Group III. 



This group is situated on the " tote" road, near the brook crossing near Wight's 

 Camp. 



Trees girdled June IS. 



Tree No. 16: Diameter, 17 inches: sound roots, and healthy crown. June 19, 

 two Dendroctonus galleries, one at girdle, the other 1 -\ inches long. July 11. about 

 a dozen Dendroctonus galleries, the longest ones 2 inches: without eggs or larvae; 

 several single beetles dead in short galleries and embedded in the pitch. Septem- 

 ber 1, six or eight new galleries, without eggs or larva?. 



Tree No. 17: Diameter, 15 inches; hack-girdled at base of roots. June 19, not 

 attacked. July 11, one Dendroctonus gallery with eggs. September 1. one gallery 

 without larvae. O tober 4, no additional attack; tree still living. 



Tree No. 18: Diameter, 17 inches; sound roots, and large crown; an infested 

 tree 20 feet away. June 19, lightly infested by Dendroctonus; galleries about 1 

 inch long: had entered at girdle and elsewhere; also some Xyloterus in girdle and 

 elsewhere. July 11. thoroughly infested by Dendroctonus; galleries 3 inches long; 

 Polygraphus (?) also in bark. September 1. thickly infested with Dendroctonus, 

 mainly in the pupa stage; Xyloterus in wood; sapwood brown and blue; leaves 

 falling. October 4. recently developed adults and numerous Xyloterus; leaves 

 half fallen. 



A 19-inch tree, the same distance from the infested trees, as well as others 40 feet 

 away, were not attacked. 



Tree No. 19: Diameter. 17 inches: sound roots and full top. June 19, not 

 attacked. July 11. abundantly infested by Dendroctonus: Xyloterus in gir- 

 dle. October 4. large larva?, pupa?, and partly and fully developed adults of 

 Dendroctonus. 



The above trees were all at the time of girdling within a few rods of infested 

 trees. 



Tree No. 20: Diameter. 15 inches; standing in group of trees killed last summer; 

 roots sound. July 11. infested with Dendroctonus: some galleries -U inches long, 

 containing eggs, but none hatched. September 1. abundantly infested with Den- 

 droctonus. pupa?, and large larvae. October 4, large larva? to light-colored beetles. 



July 11. two other trees in same bunch, not girdled, were found to be attacked. 

 I am not certain that they were killed, but think that they were not. 



