D4 College of Forestry 
cerambycid — Monohammus scutellatus; the melandryid — 
Serropalpus barbatus; and the two siricids Urocerus albr- 
cornis and Sirex abbotii. There can be no doubt that Lep- 
tostylus sex-guttatus and Melanophila fulvoguttata may also 
breed in this upper trunk region, as each of these is found 
both in the lower trunk and in the tops and branches, but 
the limited amount of material confined in our breeding 
cages did not give rise to any. JL. sex-guttatus breeds by 
preference in the thin barked tops and limbs and would there- 
fore be more likely to be found in the upper trunk than in 
the lower. M. fulvoguttata on the other hand is more typi- 
eally a trunk-inhabiting form and in spruce and hemlock is 
found throughout the trunk region and only to a lesser extent 
in the tops and limbs. It is likely that its preferences in 
larch would be similar but the small number bred from larch 
does not allow us to draw an adequate conclusion. 
D. simplex, as previously stated, is confined entirely to 
the lower trunk of standing trees, but may breed in the upper 
trunk of felled trees. The limiting factor here is then very 
apparently height from ground rather than the character of 
the bark. The cerambycids Asemum moestum and Phyma- 
todes dimidiatus are two other beetles which have been bred 
only from the lower trunk. Of these the former is practi- 
cally confined to the lowermost part of the trunk and none 
were bred from wood more than three or four feet from the 
ground. P. dimidiatus while not confined to such a lmited 
area of the lower trunk was not obtained from wood more 
than ten feet from the ground. 
The Tops and Limbs of Dying or Recently Killed Larch 
Trees.— The tops and limbs of recently killed larch present 
conditions quite different in several respects from those in 
the trunks. In the first place they are inaccessible to a 
number of forms which are clumsy fliers. Aside from this, 
the much thinner bark allows the beetles more ready access 
to the inner bark and sapwood. The inner bark, however, 
neither furnishes so plentiful an amount of food as does the 
thick bark nor does it retain so much moisture. However, 
the thin-barked parts of the tree seem to offer conditions 
