Fig. 2. Horizontal and radial sections of oak stem showing burrows of Micros e 
isd 
M. 
i um. are three iis species, which may be distinguished a as 
oll 
I. Thorax uniformly black ; elytra yellow with black ed “tere : 
DM joint of antenna with apex produced at inner pi On s 
tre Linn. 
Fi least posterior half of thorax yellow. Elytra yellowish, with a — 
dark longitudinal stroke along middle. 
i, Elytra with deep and somewhat wrinkled punctured strie; terminal 
point of antenna e — riangular, produced at inner angle of baie 
In T eme s trees T. signatum, Fabr. Mentis 
lytra with very Stie.rome ot shart aga ; terminal joint rounded 
ai doen ofantenne. In conifers. T. lineatum, Oliv. 
Of the two species living on deciduous trees, 7. domesticum attacks 
principally beech, rarely oak, uv iud maple, &c. 
; irris Ae enerall also in birch, 
a matter of doubt as to whether it is T. domesticum or T. s biakan D but 
the strong punctuations of the vada (almost the only point Perit oo 
for differentiation) indicate the 
They are similar in habit, and dio. distinction between them is of no 
economical importance. 
They do not injure the life or nutrition of a tree, but by confining pos 
nemi cia to dead or dying timber they render it unfit for commerc ial -— 
“Title can > done to diminish their numbers in v where th 
