REPORT OF THE ENTOMOLOGIST AND BOTANIST. 215 



the linseed oil all right, put on lightly, not thoroughly saturated, after the trees are 

 out in full leaf, but not before. The linseed oil will kill the beetles, but after a time 

 they will trouble the tree again if some are left anywhere. I noticed this, which you 

 may probably know, that old trees, say nine or ten years planted, are more likely to be 

 troubled with the beetles ; still, when numerous, as you saw, they attack young trees. 

 The whitewash was nut effective. I was thinking, would it do to add to the white- 

 wash carbolic acid sufficient to make a strong odour ? Some bugs are sensitive about 

 bad smells. Would this injure the tree 1 And would it kill the bugs, do you think 1 



" In reply to yours of July 27th, I examined my trees and found early in August 

 the beetles running over the bark and sinking fresh burrows. About the middle of 

 August they are very numerous, so much so that on a small tree only two inches in 

 diameter, I killed 64 beetles in about 15 or 20 minutes, about sun-down. They must 

 certainly have been a fresh brood, so numerous were they. I believe, with you, that 

 beetles will mature from the eggs laid this autumn and pass the winter in the bark." 



" December 31. — We found the beetle active during mild weather in February 

 last, and in this December they worked nearly the whole month. 



" Now, my opinion is, that it is dangerous to use coal oil, or linseed oil either, on 

 peach trees before they have the rough furrowed bark. I have several other trees now 

 which I observed this morning, to which linseed oil was applied freely ; one I noticrd 

 was about dead, a seven year old smooth bark ; several others, a year older, partially 

 dead, all smooth bark ; others older, rough bark, apparently all right. I think, not- 

 withstanding what you have heard concerning application of coal oil for San Jose Scale, 

 that it will have to be used with great caution. I regret it very much, too, it is so 

 easily applied and so effectually disposes of them." — C. E. Fisher. 



The following letter refers to the same subject : — 



" Queenston, December 20. — In reply to yours of the 17th instant, I would say 

 that the Peach Bark-borer can injure seriously, and if not interfered with, will kill peach 

 trees about the third or fourth year after the attack begins. I think all the experi- 

 ments I have tried have had some good effect ; but none have been quite successful. I 

 have used coal oil emulsion applied with a spray pump ; also, whitewash and Paris green 

 applied in the same way ; also, plain whitewash applied with a brush, and of different 

 degrees of thickness. All the applications seem to check the work of the borer. The 

 Paris green and whitewash, sprayed with force, and the thick whitewash, seem to give 

 the best results. I applied the whitewash and Paris green twice, the whitewash once. 

 I have been told that this borer is known as the Elm-tree Bark-borer, and I notice that 

 they seem to attack peach trees standing near forest trees, more frequently." — Capt. 

 James Sheppard. 



The Peach Bark-borer, and the Elm Bark-borer (Hyhsinus opaculus, Lee), although 

 atone time thought to be identical, are entirely distinct, as can be seen at once by exam- 

 ining the antennas. In the case of the former, the club of the antenna; is composed of 

 three separate flattened joints or plates opening like the leaves of a book : although very 

 small, these are easily distinguishable when the insect is moving. In the Elm Bark- 

 borer the club is slightly compressed, ringed, pubescent and oval pointed. This mistake 

 was first made by Dr. Harris many years ago, and was repeated by subsequent writers 

 until attention was drawn to it by Mr. E. A. Schwarz, of the Department of Agricul- 

 ture at Washington, who has made a special study of the Scolytidce, and who has 

 examined the specimens upon which Dr. Harris based his statements. 



The above extracts show that a certain amount of success has attended all of these 

 experiments ; and, although some important facts have been found out with regard to 

 the life history of this serious enemy of the peach, particularly as to the early date when 

 the beetles are active and the comparatively long time before the eggs are laid in the 

 spring, yet further investigations are necessary to discover the best treatment and the 

 most suitable remedy. Arrangements have been made for further experiments next 

 season. From the work of Mr. C. L. Marlatt, in fighting the San Jose Scale, as detailed 

 in Insect Life, VII., page 116, it would appear that coal oil emulsion of a much greater 

 strength than was tried in Mr. Fisher's orchard, may be applied with safety to peach 

 trees, and it is just possible that the death of Mr. Fisher's trees may have been due to 



