PROCEEDINGS OF THE SUMMER MEETING. 17 



SHOT-HOLE PEACH-TREE BORERS. 



While the June beetles were still at work on our shade trees, I was 

 called to IMcCord's, near Grand Rapids, to look after a peach orchard that 

 was apparently being killed by some little shot-hole borers. This name 

 is given the beetles because they are so small that, when they bore into 

 the tree the holes which they make are no larger than holes made by shot; 

 and, when numerous, the tree has the appearance of having had several 

 loads of scattered shot fired into it from different directions. 



On reaching Mr. Chas. B. Peet's orchard, I found about ten acres of 

 very thrifty four-year-old trees situated on a high hill sloping to the north 

 and west and protected by woods on the other two sides. The soil was 

 mostly sandy, though there were spots that varied even to the stiff est 

 clay. The soil and slope apparently made no difference in the attack. 

 The beetle often attacked the largest, finest, and most thrifty-looking 

 trees in the orchard, with little or no regard to location. At the time I 

 was there. May 25, these injured trees had blossomed and were as full of 

 fruit as the others. The leaves, however, told the story, as they were 

 turning yellow even though not yet fully developed. On examining the 

 fibrous roots of such trees, one would find them quite dead, and the bark 

 on the larger roots was brown. On peeling off the bark on the trunk 

 and larger limbs, scores of these little shot-holes would be seen. Some 

 of the beetles would be but little bevond the bark, while others would be 

 from an inch to an inch and a half from the outside, and running usually 

 toward the heart, though many were found running in various other direc- 

 tions. Every once in a while a hole was found to branch in two or more 

 directions when a short distance in from the surface. Each of these 

 branches contained a beetle. This peculiarity was probably caused by 

 one or more beetles following into the hole behind the one that made it, 

 and as soon as they came upon the beetle in the lead, anti could go no 

 further, they at once commenced to side-tunnel a branch. 



The trees were found to contain three distinct species of scolytid, viz.: 

 Monarlhrum fasciatum Say, Monarthrum mali Fitch, and Xylehoriis fus 

 catus Eich. The two species of Monarthum have been known to injure 

 fruit trees before, particularly the apple; the Xyleborus has been found 

 in oak and hickory, but I find no record of its work on fruit trees, and the 

 department at Washington say that it is the first incident of the kind 

 known to them. None of the species, I think, have ever been known to 

 attack the peach before. This entire family of shot-hole borers prefer 

 d^ing or diseased trees for their work, but there seems to be little doubt 

 that they at times become injurious to live, thrifty trees. 



This is not the first injury to peach trees by borers of this kind that we 

 ever had. Even this spring we have had reports from Sanilac. Ionia 

 county, and from South Haven, of similar work. On several different 

 occasions we have received samples of peach-tree trunks from South 

 Haven, or near there, but in each case there were only the little holes left 

 in the dead trunk, and no beetles, and consequently we could only guess 

 what the depredator was that caused the injury. There is a species, 

 Phlcpotribus liminaris Harr., that has been known to injure peach trees in 

 the same way in the New England states, and we suspected the same 

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