76 



Mr. 0. B. Galusha, as one of the ad interim committee of the Illinois 

 S.tate Horticultural Society, visited Cobden, South Illinois, and col- 

 lected large quantities of the roots infested by this Plant-louse, which 

 he transmitted to Mr. C. V. Eiley for examination, expressing the 

 opinion, at the same time, that "the destruction of the apple-orchards, 

 in this vicinity, by this insect, or by the fungus that accompanies its 

 operations, seems inevitable, unless a remedy is soon discovered.' 

 (Prairie Farmer, June, ]8G7, p. 397.) When I was at Cobden my- 

 self, in November, 1867, I personally examined the orchard of Mr. 

 Paul Wright, and found that small groups of apple-trees had been 

 killed by this Plant-louse in several directions, some of them having 

 perished with the half-matured fruit still hanging on their boughs. 

 In one spot of ground no less than nine trees, all in one square patch, 

 had been killed by it; and separated therefrom by only a single row 

 of living trees, there were two or three more dead trees. Digging down 

 to the roots of the live trees, that intervened between these two gaps in 

 the orchard, I found at once great numbers of the enemy — none of 

 them, however, in the winged state — and also abundance of roots, 

 clubbed, knotted and distorted, in almost every imaginable form, by 

 their. punctures. On examining the trees, that had been killed, sev- 

 eral months previously in the summer, I found that their roots were 

 now completely rotted, =o that nothing remained of them but a few 

 short snags attached to the butt, and the first high wind that came 

 would necessarily blow the tree over. On the dead and decayed roots 

 of such trees, I found, of course, no Koot-lice ; but Mr. Wright assured 

 me that they were to be met with on the roots in great numbers in the 

 summer, when the trees first began to droop and wither. Among the 

 living roots on which I had found living Eoot-lice, there were a few 

 roots as completely dead and rotten as those of the dead trees. 



At first I imagined that every tree must have been infected, when 

 it was originally received from the nursery. But Mr. Carpenter sub- 

 sequently informed me, that he had found the insect in abundance on 

 the roots of seedling apple-trees, in the autumn following the spring 

 when the seed was sown; and another fruit-grower told me, that he 

 had seen it on the roots of seedling apple-trees, when no other apple- 

 trees were within 300 yards, and on land lately reclaimed from the 

 forest. Clearly, therefore, the insect must pass from tree to tree, 

 either in the winged form which Dr. Fitch found it to assume in 

 October, in the State of New York, or by some of the wingless indi- 

 viduals, that inhabit the trunk or limbs, being blown to and fro by 

 the winds through the instrumentality of the light, feathery down, 

 which exudes from their bodies. Probably the species has always 



