1898.] ENTOMOLOGICAL NEV.'S. 255 



DEPARTMENT OF EGONOMIG ENTOMOLOGY. 



Edited by Prof. JOHN B. SMITH, ScD., New Brunswick, N. J. 



Papers for this department are solicited. They should be sent to the editor. Prof. John 

 B. Smith, Sc.D., New Brunswick, N.J. 



Preliminary Notes upon an Important Peach Tree Pest.— 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 inspections proved conclu- 

 sively 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 (Phytophidae) 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 three feet in height. They were, what I have termed, " dog- 

 legged" trees, on account of their very crooked condition. 



Over 125,000 peach trees were rendered worthless by the pest in this 

 State in 1896 and '97. Not knowing of any reference to similar injury, I 

 assumed the creature was new, especially in this country. Mentioning 

 the matter to Prof. M. B. Waite, of the Division of Vegetable Pathology, 

 U. S. Department of Agriculture, in his office, the Fall of 1897, I found 

 that he had discovered the same pest several years ago, and had the 

 original trees in his office upon which he made his observations ; but, at 

 that time, had published nothing upon the subject. The credit of the dis- 

 covery of this pest therefore belongs to Prof. Waite, and to him the spe- 

 cies will be dedicated should it prove new. 



I have continued my observations this season, as Prof. Waite told me he 

 did not intend studying its habits and life history. 



t rom recent observations I am now thoroughly convinced that the mite 

 is carried back to the nursery in buds. I have seen the same species, or 

 one very closely allied, at work upon plum trees in the nursery row this 

 season. It is also quite common in many old peach orchards and is 

 doing much damage to buds upon bearing trees. I am at work upon 

 remedies for its suppression and control, as it is of great economic im- 

 portance, having seriously injured more than a hundred thousand peach 

 trees this season. I have in preparation a more extended article on the 

 pest. — W. G. Johnson, State Entomologist. 



Md. Agr. Col., Oct. /, i8g8. 



C. F. Baker will leave Auburn, Ala., on Nov. 1, 1898. He goes on a 

 two years' leave of absence as field botanist to the Herbert H. Smith 

 Exploring Expedition, which will be engaged in biological work in North- 

 western South America. All letters and packages for him should be ad- 

 dressed to St. Croix Falls, Polk Co., Wisconsin. 



