56 



The Elm Bark Louse ( Gossyparia spuria Modeer ) . The females of 

 this species are dark red, bordered with white wax and one-tenth of an 

 inch in length. They are usually arranged along cracks or fissures in the 

 bark of trunks and limbs, and lie irregularly on the twigs. They suck- the 

 sap from the inner bark, and the leaves below infested limbs become coat- 

 ed with honey-dew and wax. The young appear in late June or early 

 July and are most readily controlled at that time. 



Imported elms have been killed by this insect near Ottawa in the 

 last few years. It may be controlled by spraying with kerosene em.ulsion 

 or fish-oil soap when the young are crawling upon the bark, or by us- 

 ing a stronger mixture early in the season before the buds have opened. 



The Locust Borer (. Cyllene robineae Forst ) has been quite destruct- 

 ive in Southern Ontario to Acacias. The powerful grubs drive their 

 tunnels throughout the trunk and kill the trees. I have no record of 

 this species actually from Quebec, but it may be expected w^herever Aca- 

 cias and locusts are grown. 



The control of this species is particularly difficult. The infested trees 

 should be felled during the winter and burned before spring. 



Bark-beetles and Long-horned beetjles are at times destructive to or- 

 namental conifers. When Pines, Spruces or Firs are seriously attacked by 

 either of these classes of borers the trees are past all hope of recovery 

 and should be cut and burned to destroy the contained beetles. These beet- 

 les rarely attack healthy shade-trees in Canadian cities. Usually the tree 

 is very seriously weakened before the Bark-beetles or Horned-beetles en- 

 ter it. Every effort should be made to keep the tree in a thrifty condit- 

 ion. 



The Bronze Birch Borer ( Agrilus anxius ) . This small elongate darjc- 

 colored beetle and its very elongate whitish grubs are the most serious 

 enemies of our ornamental white birches. Imported varieties suffer more 

 seriously than native species. The grubs construct verv long winding tun- 

 nels in the sap-wood of trunks and large and small iDranches. Evidence 

 of their w^ork appears in the rusty patches on the bark of trunk and 

 limbs, and the dying tops and branches. 



Sooner or later the branches become girdled and the tree weakened 

 by the numerous interlacing tunnels cut through the sap-wood. The tree 

 begins to die usually at the top, but the removal of the top is then of 

 little use, for the grubs are by that time working in many parts of the 

 tree. 



The only method of controlling this very destructive species is to cut 

 out and burn all infested trees as soon as the injury becomes apparent. 

 This reduces the number of the pests and prolongs the life-time of the 

 remaining birches. 



