Reports to the Board of Agriculture. 169 
Protective and Remedial Measures. 
It does not appear certain that sickly trees are more attacked than 
healthy ones, but it is as well to keep up healthy and well-stocked 
plantations where these pests frequently occur. All the pine sawflies 
have many enemies, which should be protected. Amongst these must 
be mentioned mice and squirrels, which devour large numbers of the 
larvae hibernating in the cocoons during the winter, the cuckoo, 
goat-sucker, starling, which also devour numbers of the larvae and 
adults. 
When trees are invaded the larvae may be collected by shaking 
them from the trees on to cloths spread on the ground. Trees that 
have been attacked should have the ground around their trunks 
examined in winter, when the heaps of cocoons may be collected and 
destroyed. Ground beneath such trees may be deeply ploughed in 
winter so as to bury the stray cocoons. Ornamental trees in parks 
and gardens may be speedily cleared by spraying with hellebore wash 
or arsenate of lead. 
Another plan is to place fresh pine boughs beneath the trees and 
then jar the larvae- off ; all those that fall to the ground collect on 
the boughs strewn about and can then easily be burnt. 
An invaded tree should always be isolated, for the larvae will 
migrate to another as soon as the food begins to fail. This may be 
done by placing a ring of tar on the ground around the base of 
the tree and by sticky-banding the trees just around the attacked 
one. 
Deep trenches, two or more feet deep may be dug also around 
infested trees, with perpendicular or inwardly sloping sides so as to 
catch the larvae when migrating. 
Larvae of the Lime Hawk-Moth on an Ash Tree. 
The large caterpillar of the Lime Hawk-Moth (> Smerinthus tilise) 
was sent by a correspondent at Kensal Rise that was feeding on an 
ash tree. 
The moth appears in May and June and lays her eggs upon lime 
and elm as a rule. The eggs are oval and plump in form, shiny pale 
green, about 1-75 mm. long. The larvae appear in about three 
weeks after the eggs are laid ; when mature they usually bury them- 
selves under the ground in the autumn and then pupate. The pupa 
is one and a-quarter inches long, dark brown with a reddish tinge, 
the abdomen terminating in an abrupt triangular strong spine, ending 
