126 
SPOLIA ZBYLANICA. 
the departure, the ascent of the midrib, the turning round, and 
the cutting of the cable. But although the chief events, which were 
repeatedly observed, are remarkably constant, there is considerable 
variation in detail, both as regards the order of procedure in the 
construction of a shelter and in the manner of feeding. Occasionally 
a caterpillar comes quite outside its house in order to feed upon a 
neighbouring spray for a short time, after which it returns home. 
Fig. 1 is a composite outline showing a young caterpillar, 10 mm. 
long, with pale green body and orange-coloured head, engaged in the 
operation of discarding its second tube-shelter. It is seen beginning 
to leave the tube below, and again above, biting across the midrib. 
That this was its second shelter was inferred from other observations, 
the earliest tube not being noted in this instance. When first 
Fig. 1.—Fiagram showing a caterpillar about to leave its tube-cell and 
ascend the bare midrib; and again on the leaf-blade, biting 
across the midrib. 
hatched the larvse are dark red in colour, retaining a red colour 
until leaving the first tube-shelter, which is very small and easily 
overlooked. A few minutes after ridding itself of its now useless 
shelter, the larva shown in Fig. 1 moved along the leaf-blade and 
began to lay the foundation of a new tube-cell by cutting across 
one-half of the blade of the spray at a distance of about 2J inches 
from the original cut end. 
The usual method of forming a shelter is shown in Figs. 2-5. 
In these figures the projection at the free end of the leaf-spray is 
not the true apex, but it is the point where the pedicle of the previous 
house was bitten off. At a distance of 2J inches from this point 
a larva was seen making a curved incision across one-half of the 
spray, not quite reaching the midrib. It then spun a silken strand 
by repeated transverse movements of the head across the head of 
