92 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
In all, 43 experiments with remedial and preventive measures were 
conducted during the summer, results of which are given herein. 
Field observations in this locality seemed to show that apparently 
healthy trees are attacked and, although the beetles probably do not 
form egg burrows in these, the loss of sap from the burrows made by 
the adults in the bark is sufficient to cause the trees to become very 
much weakened. 
HISTORY. 
The first published notes on this insect were made by Miss M. H. 
Morris, about 1849-50. At that time Miss Morris credited Zomicus 
liminaris as being the cause of “peach yellows,” and so expressed her 
belief in several articles published in different magazines of that time, 
stating that the beetles were quite numerous about peach trees suffer- 
ing from “ peach yellows.” These suggestions made by Miss Morris 
probably led Harris to include the insect in his treatise on “The 
Insects Injurious to Vegetation,” published in 1852, where he briefly 
describes it under the name Zomicus liminaris, this later being 
changed to Phlawotribus liminaris. The following extract gives his 
description : 
There is another small barkbeetle, the Tomicus liminaris of my catalogue, 
which has been found in great numbers by Miss Morris under the bark of 
peach trees affected with the disease called the ‘“‘yellows” and hence supposed 
by her to be connected with this malady. I have found it under the bark of a 
diseased elm, but bave nothing more to offer from my own observations con- 
cerning its history, except that it completes its transformations in August and 
September. It is of a dark-brown color, the thorax all punctured, and the 
wing covers are marked with deeply punctured furrows and are beset with 
short hairs. It does not average one-tenth of an inch in length. 
The beetle spoken of above as working in elm bark was later found 
by Mr. E. A. Schwarz, of this Bureau, to be Zylesinus opaculus Lec., 
he having examined the specimens used by Harris and named it the 
elm barkbeetle.* (This specimen, in Mr. Harris’s collection, was 
called Zomicus liminaris and catalogued as such, as is shown by 
copies, taken by Doctor Hopkins, of the original notes.) ? 
For many years this insect did not become sufficiently important 
to demand special study, either of its life history or for the deter- 
mination of remedial measures. Reference to this species has been 
made at different times, as in the annual reports of the entomologist 
of the Canadian experimental farms, and by entomologists in the 
4 Attention is here called to Mr. Schwarz’s article on p. 149, Vol. I, No. 3, 
Proceedings of the Entomological Society of Washington (1889), on Hylesinus 
opaculus. 
®The genus Phiwotribus is being revised by Doctor Hopkins, who will dis- 
cuss the synonymy and other systematic features in a bulletin of the technical 
series of this Bureau. 
stomatgionte Smet Be. 
aa A i Ne i Sai a Se al te Bide PAT ee 
