Indian Forest Records . 
[Vol. VIII. 
34 
distribution of early larval attack over tlie whole bole of the tree, and 
the very rare occurrence of two larval burrows near each other, may 
indicate that the eggs are laid singly or in small numbers. In connec¬ 
tion with this subject it is worth recording that female moths in cages 
showed a constant tendency during the first few days of life to climb 
upwards and remain at rest on reaching a summit; later on this phase was 
replaced by negative phototropism and a desire to squeeze into dark 
shelters at a low level. A few moths captured in the open were taken 
resting on the bark of teak trees; when disturbed they crawled up¬ 
wards without attempting to fly. In order to determine if eggs were 
laid on the bark or scattered on the ground Mr. W. C. Rooke tar-banded 
50 trees on the 26th April, 1916, near the Observation Area, N. 
Toungoo at 1^ feet above ground and removed all undergrowth. No 
signs of boring larvae above the bands were observed until the 23rd 
May, indicating that eggs were laid on the trunks after the tarring of the 
trees, or if the incubation period is over 3 weeks that eggs were laid 
above the tar-bands before their application. 
LARVAL HABITS. 
The Bark Chamber and Early Larval Work. 
[Plate iii, Fig. 5]. 
The first larval instar is at present unknown (see p. 28) ; pre¬ 
sumably the larva on hatching from the egg bores straight into the bark 
as the smallest (2nd instar) larvae have been discovered in this position. 
The initial excavation is confined entirely to the bark ; the burrow is 
at first extended from the point of entrance for about half an inch upwards 
and downwards in the inner bark and bast. It is then enlarged laterally 
and carried inwards until the cambium is reached by biting out small 
recesses, which coalesce into larger embayments and sometimes extend 
in short tunnels. At this stage the larval burrow is filled with pellets 
of excrement and fragments of bast wet with sap, and no sign of its 
presence is visible on the outside except perhaps a thin trickle of sap and 
a film of black bark-dust. [See Plate iii, fig. 5]. The 2nd stage larva 
lives for a few days at least in a semi-liquid mass of chewed-up tissue, 
and the modification of the spiracles at this period is probably 
correlated with anaerobic conditions. The period may also be one of 
high mortality, since the number of larvae that develope their galleries 
to the next stage is comparatively very low. 
The larval chamber is enlarged further, and mainly in a longitudinal 
directi on, until its inner wall is formed by a shallow groove in the sapwood 
[ m J 
