270 CONNECTICUT EXPERIMENT STATION REPORT, 1901. 



it hardly seems probable that the beetles attacked perfectly 

 sound trees in the beginning. But wherever a tree is injured 

 by accident or weakened by any cause, an excellent breeding- 

 place for the beetles is formed. In the summer of 1900, the 

 drought was extremely severe in the vicinity of New Haven, 

 and many trees suffered. The writer observed several hickories 

 in the city parks that lost some of the branches or the entire 

 top. The hickory trees on the Hillhouse place are in part 

 situated on a dry knoll and it seems probable that some of these 

 were injured by the drought. These injured trees were attacked 

 by the beetles, which multiplied to such an extent that the adults 

 in search of food attacked the twigs and branches of the more 

 vigorous trees, thus weakening them sufficiently to enable the 

 species to breed in the trunks. Finally a large number of good 

 trees perished. 



It was recommended that as many of the insects as possible 

 be destroyed in the wood and bark of the trunk and that the 

 remaining trees be ke'pt in the best possible state of vigor by 

 fertilizing, removing dead wood, etc. It is doubtful whether 

 anything more than general preventive measures can be 

 employed against these bark borers. Possibly in case of a 

 severe attack upon thrifty trees it might be worth while to 

 spray the foliage, twigs, and branches, as well as the bark of 

 the trunk, with a thick whitewash to which Paris green had 

 been added. Some of the beetles thus might be killed while 

 feeding upon the twigs or when tunneling into the bark of the 

 trunk to make the brood galleries. 



SEVERE ATTACK OF THE FALL WEB-WORM. 

 Plyphantria cimea Drury. 



The fall web-worm was very abundant during the season of 

 1901, and during August and September defoliated a great 

 many trees including nearly all kinds of fruit, shade, and forest 

 trees. The attack was not local, but extended all over the 

 State and into Massachusetts and New York. 



In September the writer observed defoliated trees in the 

 forests along the Shepaug river valley, along the Air Line and 

 Shore Line railroads, and through the central portion of the 

 State. Along the Northampton railroad, many trees had lost 



