104 DECIDUOUS FKUIT INSECTS AXD INSECTICIDES. 



Disease." An abstract of these remarks, published in Science, 1 is 



as follows: 



Mr. M. B. "Waite presented a communication on a new peach and plum disease 

 caused by a species of mite attacking and killing the terminal bud of the very young 

 trees. The resulting loss in the value of the trees was considerable, as many thousand 

 trees would be affected in one nursery. A similar disease prevailed in the Japanese 

 quince. 



No further reference to this trouble appears to have been published 

 by Prof. Waite. In Entomological News, 2 under the caption " : Pre- 

 liminary notes upon an important peach-tree pest/' Prof. W. G. 

 Johnson states: 



In September, 1896, while inspecting the nurseries of Maryland, I found many 

 peach trees dwarfed and stunted, and at first glance attributed it to the black peach 

 aphis (Aphis prunicola Kalt.). Later inspection proved conclusively that the trouble 

 was not caused by that insect, but by some other creature. A lot of trees were examined 

 in my laboratory and I discovered a minute mite (Phytoptida?) working behind and 

 in the buds. In nearly every instance the terminal bud had been destroyed, thus 

 forcing the laterals. These in turn would grow for a short time and were then killed. 

 As a consequence the trees were crooked, stunted, and not salable, being less than 3 

 feet in height. They were what I have termed dog-legged trees, on account of their 

 very crooked condition. 



Prof. Johnson's note led to some comment by other entomologists, 

 and Prof. F. M. Webster, in the Entomological News, 3 under the 

 title "The new peach mite in Ohio," reports the finding by Mr. C. W. 

 Mally, in the course of nursery inspection work, of the characteristic- 

 ally injured peach trees, though the depredator was not determined. 

 It is stated that in one very extensive nursery the greater portion of 

 a block of 500,000 young peach trees was more or less affected and 

 the presence of the pest was noted also in another nursery in the 

 same general region. 



Prof. P. H. Rolfs in a note, "The new peach mite," in Entomo- 

 logical News, 4 called attention to the. distribution of a mite which he 

 erroneously thought to be the one referred to by Messrs. Johnson and 

 Webster, namely, a phytoptid, causing a silvering of peach leaves — 

 a mite which was subsequently described by Banks under the name 

 Pliyllocoptes cornutus from material from the insect ary grounds in 

 Washington. A further confusion is evidenced in a note by Mr. 

 Claude Fuller, in Entomological News, 5 in which attention is called 

 to a silvering of the leaves of deciduous fruit trees as noted by him 

 in South Africa and due to the attack of a very small Phytoptus. 

 This is very probably similar if not identical with Pliyllocoptes 

 cornutus. 



Messrs. Webster and Mally refer briefly to the subject in an article 

 on "Insects of the Year in Ohio," read before the Association of 



i Science, new series, vol. 6, Oct. 23, 1897, p. 707. * Ent. News, vol. 9, Mar.,1899, p. 73. 



2 Ent. News, vol. 8, Dec, 1898, p. 255. 5 Ent. News, vol. 9, Sept., 1899, p. 207. 



s Ent. News. vol. 9, Jan.. 1899, p. 14. 



