138 ENTOMOLOGICAL SOCIETY 
Mr. Schwarz read the following paper : 
ON XYLEBORUS PYRI AND AN UNDESCRIBED ALLIED SPECIES. 
BY E. A. SCHWAKZ. 
The galleries made by Scolytid beetles are divided into such as are more 
or less between the bark and the outermost layers of wood, and such as 
enter the solid wood. Those of the former class are readily investigated 
and described, and the burrows of quite a number of our native species have 
been made known, although only a small proportion have been illustrated by 
figures. The Scolytids of the second class that bore into the solid wood are 
much less numerous, and their galleries much more difficult to investigate. 
To fully illustrate their work two figures are necessary, viz., a transverse 
section of the branch or trunk containing the galleries, and a longitudinal 
section through the burrows. Only very few of these species have hitherto 
been described by American authors, c. g., Gnathotrichus materiarius and 
Monar thrum mali, by Dr. A. Fitch; Corfkylus punctatissimus, by Dr. C. 
H.Merriam, while two or three other species have been briefly referred to. 
The most frequently mentioned example of this class is the Pear-blight 
beetle, Xyleborus pyri, of which W. D. Peck published an account as early 
as 1817 (Mass. Agric. Jour., iv, no. iii, pp. 205-207). His account is 
quoted, in abstract, by Dr- Harris (Treat. Ins. Inj. to Vegt. , Flint ed., p. 
91), and has been faithfully copied by every subsequent writer whenever 
there was an opportunity to refer to the Pear-blight beetle. In view of 
the knowledge we now possess of the life-history of Scolytids, through the 
investigations of Ratzeburg, Ferris, Altum. Eichhoff, and others, it seems 
strange that no one has ever pointed out the errors in Peck's account. He 
starts with the statement, that the female beetle deposits the egg in the bark, 
a statement which is erroneous, since all Scolytids, without exception, 
oviposit within their galleries. Then he proceeds to describe the gal- 
lery as consisting of a somewhat winding passage leading through the bark 
into the wood, and turning around the core of the twig concentric with the 
bark. This description is imperfect, and shows that Peck made only a 
transverse section of the twig. Had he made a longitudinal section he 
would have noticed that this long gallery is intersected vertically by a 
number of shorter galleries. That these vertical galleries exist is evident 
from remarks by Dr. Harris, which he adds, without further comment, to 
his quotation of Peck's account. 
The galleries of Xyleboriis pyri when completed must be very similar to 
or identical with those of the allied European A", dispar as figured by 
Eichhoff (Europ. Borkenk., p. 280), and I have myself on a former occasion 
expressed the belief that these two species are specifically identical ; in other 
words, that our pear-blight beetle would prove to be an old importation 
from the Old World. The burrows of all Scolytids which enter the solid 
wood are constructed after the same principle, at least so far as known to 
us. Only a single species is known to form a notable exception, viz., the 
European A". Saxcsem'. which, without making any galleries whatever. 
