Reports to the Board of Agrieitttitre, 169 



Protective and Memedial Measures. 



It does not appear certain tliat 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-suckor, starling, which also devour numbers of the larv;e 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 sliould 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 l)y spraying \\\x\\ iiellebore wasli 

 or arsenate of lead. 



Another plan is to place fresh pine boughs l^eneath the trees and 

 then jar the larva' off; all those that fall to the ground collect on 

 the boughs strewn aliout and can then easily be burur. 



An invaded tree should always be isolated, for the larva' will 

 migrate to another as soon as the food begins to fail. This may l>e 

 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 larva' when raisfrating. 



Larvae of the Lime Hawk-Moth on an Ash Tree. 



The large caterpillar of the Lime Hawk-Moth (Smermthus tiJix) 

 was sent by a correspondent at Kensal Else that was feeding on an 

 ash tree. 



The moth appears in May and dune and lays lier eggs upon lime 

 and elm as a rule. The eggs are oval and plump in form, shiny palo 

 green, about 1-75 mm. long. The larvfc 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, 

 ihe abdomen terminating in an abrupt trinngulnr strong spine, ending 



