( I G THE EEPORT OF THE No. 36 



The Leopard Moth, Zeuzera pijrina Linne is another very destructive enemy 

 of deciduous shade-trees which may eventually spread northwards. Its large cater- 

 pillar excavates tunnels in the wood, and has become a very serious pest through- 

 out the region' between New York and Boston. 



All these species, with the exception of the Hickory Bark Beetle, were im- 

 ported from Europe in various ways and at different times. It is quite possible 

 that some definite minimum temperature will determine the northern limit of 

 their range; but it is probable that most of them will breed readily enough in 

 Southern Ontario. It is well, therefore, to be familiar with the appearance and 

 habits of such possible enemies, for the successful eradication of an infestation 

 could only be accomplished at 'the very inception of an outbreak. 



Thk Injurious Insects of the Woodlot. 



We have been dealing thus far with the shade-trees or ornamental trees of 

 suthcient value to the owner to warrant individual treatment. 



It is quite another matter to control the insect enemies of woodlands, chiefly 

 for the reason that we have here so many trees to deal with that individual treat- 

 ment, such as spraying, usually involves an unreasonable expense. The insects 

 involved will be those which affect indigenous shade-trees, and they may be con- 

 trolled by the same methods, limited always by the factor of expense. It mio-ht, 

 for instance, be worth while to control a serious outbreak of defoliating insects 

 in a valuable sugar bush by banding or even by spraying the trees, having in mind 

 the serious effect of successive defoliations upon the vitality of the trees, but such 

 work throughout a large strip of ordinary hush land would be quite out of the 

 question. 



We must depend chiefly upon "clean culture" for the control of insect and 

 fungous pests in woodlots. A proper system of handling the trees, by which wounds 

 of all kinds are largely prevented and the trees are given a fair opportunity for 

 healthy growth, would help to reduce the injuries from insects aiul ruiio'i. In- 

 juries from fire or from falling trees should be carefully avoided. Fire-injured 

 trees are particularly liable to insect attack, and wounds on the trunk and larsjer 

 T)ranches almost invariably become infected by parasitic fungi, as well as by various 

 insect foes. 



Boring-insects of many kinds breed largely in dying and recently dead tree^' 

 and, their parts, and spread from such material to nearby weakened trees and 

 branches, or even attack perfectly sound timber. The dying branches and trees 

 so common in most woodlots are largely caused by boring-insects and rot-causin<T 

 fungi. The control of such pests consists in removins: all injured, dving and dead 

 wood and shelf-funsfi during winter and burning it, as firewood or otherwise, before 

 spring opens, so that the contained pests are destroyed hef ore they can spread to 

 the- living trees. All slash from cu't tin o-.s should be burned during wintei- or early 

 spring. If green slash is left through the spring it serves as a trap for many hnrini; 

 iiisects, which may then be destroyed by burning^ the niles towards the end of June, 

 but fire danger, of course, must be considered first. The stumps should be cut low 

 and barked. Logs which must be left in the wo^ds during the months of .Tune and 

 July can be preserved from borers by barkino- before the last of Mav. All trees 

 which are badly. injured or dving should come out. to give place for others and to 

 remove breedinsf grounds for insects. 



Healthy trees are le=;s subject to attack by mo>!t insects and fungi, and con- 

 ditions which produce a thrifty tree growth aid greatly in preventing such in- 

 juries. 



