Reports to various Correspondents. 83 
the time. Now and then they leave the trees and wander about ; 
some never return. It is probably some of these that are found in the 
ground ; numbers of cases have been reported to me of these larvae 
being found in the earth devouring and burrowing into the roots of 
plants, such as dahlias. Normally in the spring of the third year 
the larva (Fig. 13, b) comes to the entrance of the tunnel and close to 
it forms a cocoon lined with silk and coated outside with wood chips. 
The pupation takes place as a rule in May. The pupa (Fig. 13, d) 
is rich brown with rings of sharp spines on the abdominal segments. 
The moth emerges in three or four weeks after pupation. Previous 
to the emergence the pupa forces its way out of the cocoon and 
partly out of the opening in the tree ; the empty pupal skins may 
frequently be seen in that position. When kept under unnatural 
conditions the caterpillars have taken four years to mature. 
Prevention and Remedies. 
Trees in close proximity to others that are attacked may be pro- 
tected by thickly smearing the trunks over in May with a mixture 
of clay and paraffin and soft soap. This should be made into a thick 
paint and smeared all over the trunk up to eight feet and a thick 
layer put around the base and the ground. Clay and cow-dung has 
been found to answer the purpose, but is not nearly as good as the 
former mixture. This will prevent the eggs being deposited on the 
trunk and roots where exposed. It is quite useless to scrub the bark 
as suggested by Miss Ormerod, for the eggs are laid deep in crevices 
and would not be reached in the majority of cases, neither can many 
be rubbed off as suggested. For killing the caterpillars in the trees 
the best plan is to place lumps of stick cyanide in each hole and 
smear the whole trunk over with clay, the entrances to the holes 
being firmly plugged up with the same. 
Paraffin emulsion squirted into the holes is said to be a good 
remedy, but where the tunnels are very long and tortuous it is very 
doubtful if many are killed by it. Sulphur and tobacco fumes blown 
in by means of bee-bellows have also produced good results, but no 
plan is as successful as the cyanide treatment and stopping up the 
holes with clay. 
A correspondent writes that he has saved some valuable trees by 
injecting about 2 c.c. of carbon bisulphide into the tunnel and 
closing the hole with wet clay. This almost invariably killed the 
caterpillars. 
All dead timber should be burnt in the winter or spring when 
possible before the caterpillars escape. 
G 2 
