264 



AMERICAN FORESTRY 



WiNDTHROWN FiRS IN THE SiHLWALD, ZURICH. 



this is a wire tree brush, costing two 

 dollars, which is attached to a long pole 

 and manipulated from ground or exten- 

 sion ladder, depending upon the height 

 of the tree infested with the little white 

 cocoons, which will mean so much 

 trouble for you the following spring if 

 not brushed off and burnt. 



Another weapon to fight forest ene- 

 mies is the tar band. Many species, 

 such as the canker worm and the elm 

 leaf beetle have a continuous cycle of 

 reproduction going on all summer, and 

 a colony of them will camp out on a 

 tree and ravage it of all its leaves if not 

 headed off. After losing its first crop 

 the poor tree tries to put out another, 

 and usually does, but by the time they 

 are grown a new generation of cater- 

 pillars will be on hand and this crop 

 goes also. Another crop of leaves will 

 sometimes put forth in September, but 

 usually the tree is through for the year, 

 and if the experience is repeated the 

 next year, the tree dies from suffoca- 

 tion, for the leaves are what it breathes 

 with. Spraying is, of course, one remedy ; 

 and the other is to prevent the ascent 

 of the female moth full of eggs. Luckily 

 she cannot fly in this state but must 



crawl up the trunk to the branches, in 

 the crevices of which she deposits her 

 eggs. With plenty of birds about, these 

 are cheerfully eaten and there's an end; 

 but nowadays most of them hatch, and 

 the voracious little larvae begin right 

 off on the tender spring foliage. In 

 two weeks they are full grown and let 

 themselves down to the ground by 

 spinning a long silk thread, which you 

 have often seen them do, many of them 

 being carried by the wind to infest 

 other trees. After burying themselves 

 in the ground they enter the pupa state, 

 some species remaining dormant until 

 next spring, some emerging as a moth 

 in a month or so. when they immediately 

 crawl up the tree again and start a 

 new colony of worms. Most seed 

 houses keep sticky band preparations 

 already prepared, so that the forest 

 estate owner with only a small patch of 

 woodland need not bother with tar pre- 

 paration on a large scale. I have seen 

 forests in Germany where for miles 

 every tree was banded, all along the 

 borders and into the forest about fifty 

 or a himdred feet, the idea being to keep 

 out these crawlers by catching them on 

 the border trees. These bands should 



