36 
Indian Forest Records. 
[Vol. VIII. 
are closed each with a papery operculum formed of particles of wood and 
bark in a matrix of sheet silk. A few fragments of detritus and a slight 
bulge in the bark above the chamber alone betray the presence of the 
borer. 
The Food of the Larva. 
The food of the larva is partly sap flowing from the intersected sap- 
wood vessels and partly callus tissue. The growth of secondary tissue 
is particularly vigorous in the inner bark of the injured zone, and is 
formed of highly nutritious cells, that are browsed down by the larva. 
Short arms or branches of the chamber and early ejection holes, that 
have been abandoned by the larva, are filled with fresh callus in a 
relatively short time in vigorous trees, so that a constant food- 
supply is ensured. In less vigorous trees the larva finds it necessary 
to stimulate fresh merismatic activity by boring new extensions or 
recesses from time to time. The wood-dust derived from the excava¬ 
tion of the heartwood gallery, or beehole, is apparently not eaten by 
the larva, but is ejected at intervals through holes in the wall of the 
bark chamber. 
Mature Larval Activities. 
The larva continues to feed during the growing period of the host- 
tree, and, towards the end of the cold weather or as soon as the leaves 
fall, it prepares for pupation. The final constructional work of the 
mature larva consists in an upward elongation of the heartwood gallery 
to form a pupal chamber 2 to 3 inches long ; at the same time the 
earlier work is corrected by smoothing down irregularities and 
removing debris, mainly in order to secure a continuous free passage 
from the pupal chamber to the exterior. The latest work, representing 
the construction and enlargement of the terminal portion of the 
beehole, and the correction of the curve at the junction of the vertical 
and horizontal portions of the beehole, is distinguishable by the 
lighter color of the wood contrasting with the dirtier surface of the 
earlier excavation. Before retiring to pupate the larva clears out a 
path through the sapwood chamber to the outer bark, and prepares an 
exit hole, which is roofed in with thin flakes of bark connected by 
means of silk. The ejection holes are also closed with flat discs or 
opercula of silk and fragments of wood, and usually an additional 
operculum is constructed across the mouth of the beehole, where it 
debouches into the sapwood chamber. The mature larva finally 
shuts itself in the pupal chamber with a loose wad of pale or 
[ m ] 
