UK! MEDIAL MEASURES 



93 



The practical value of most of these measures depends largely 

 upon the conditions under which they are to be applied. 

 A suggestion that is easily applicable to a few small trees in 

 an apple orchard may be wholly inapplicable to the large trees 

 in a woodland. 



The abundance of the caterpillars, the nature and number of 

 the trees infested, the season of the year, and the means at 

 hand are all to be taken into consideration. In the following 

 paragraphs I have summarized the measures which a careful 

 study of the subject leads me to think will prove of value. 

 They are arranged according to stage of growth from egg to 

 moth to which they are to be applied. 



Egg Destr2iction. On a bright day, when the trees are 

 bare of leaves, the egg-masses may be easily seen. The cut- 

 ting off and burning of these masses is often practicable in a 

 young apple orchard, although it is generally considered im- 

 practicable in orchards of large trees. It generally would be 

 out of the question in woodlands, of course, although in case 

 of a few ornamental maples or other trees on the home grounds, 

 such egg-collecting might well be worth while. The gather- 

 ing may be done by sending a sharp-eyed boy into the trees to 

 cut off the glistening masses, or by means of a pruning-hook 

 or a pair of long-handled priming-shears. The belts of eggs 

 should be burned after they are gathered. 



Killing the Toung Caterpillars. On small trees, where 

 the caterpillars are easily reached, something may be accom- 

 plished by swabbing the colonies of young larvae when at 

 rest by means of a bunch of cotton waste, old rags, or some- 

 thing similar. In rainy weather, one is more likely to find 

 the larvai massed together during the day than in bright 

 weather. 



Spraying 'with Poisons. For the apple orchards, so far as 

 concerns the caterpillars which hatch there, perhaps the sim- 

 plest way of destroying these pests is to spray the trees with 

 arsenites early in the season, before the caterpillars are half 

 grown. After the leaves are unfolded and the caterpillars 

 have begun work, the earlier this spraying is done the better, 

 except that it should not take place when the trees are in 

 bloom. The common practice in spraying is to add four or 



