, 80 



Three of the foar trees girdled on May 2i) were infested by large numbers of 

 Dendroctonus on June 19, but there were many other appai-ently healthy trees 

 which were also attacked. At tliis date no newly infested trees wei-e noticed that 

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

 extended farther, but still it appeared that the trouble spread but slightly bej'ond 

 the limits of the half acre. Amon,n- 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. iSTumerous examples of this have be(-n 

 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 ti at was belt-girdled were infested and died, while 

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

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

 last year died this. Eleven trees were not attacked. 



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

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

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

 were not attacked averaged 14.2 inches in diameter. 



Oroup III. 



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

 Camp. 



Treea girdled June 7->. 



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

 two Deni^roctonus galleries, one at girdle, the other 1 V inches long. July 1 1, about 

 a dozen Dendroctonus galleries, the longest ones 2 inches; without eggs or larva-; 

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

 ber 1, six or eight new galleries, without eggs or larvne. 



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

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

 without larvte. 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 1 1 , thoroirghly 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 larvse, pupte, 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 4tV inches long, 

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

 droctonus, pup;e, and large larva-. October 4, large larvse to light-colored beetles. 



July 1 1. 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. 



