318 PROTECTION AGAINST INSECTS. 



spinning, they are shaken down from the poles. It is preferable 



to collect the pupae. 



iv. Collection of $ moths from the beginning of July. This 



should be done as soon as they emerge, and in the earliest 



hours of the morning; it gives the best results during cool 



weather. A cloth may be covered with adhesive matter, and 



used to daub the insects. 



It is not yet fully decided whether this measure is very 



effective or not, some authorities, such as Altum, ranking it as 



the best to be adopted, and others, as Ratzeburg, considering 



it as almost useless. 



In the forests near Ebersdorf in Reuss-Greiz, between the 



26th June and the 12th August, 1868, 600,000 ? were destroyed 



at a cost of 270. 



v. Trenches are usually of little use. Smearing the stems 

 in winter from the ground up to the large branches with a 

 mixture of lime ( bushel), soft soap (3 lb.), potash (J lb.), clay 

 and cow-dung destroys the eggs. This method can be used 

 for orchard trees only. 



vi. The application of high grease-bands about 2 in. wide at 

 a height of 16 k to 20 ft. from the ground, above the places 

 where eggs are laid. This should be done at the end of March 

 or April, and the bark here is sufficiently smooth, and requires 

 no preliminary scraping. The rings are smeared by means of 

 a broad brush fastened at right angles to a long pole. This 

 has in many cases proved an excellent remedy. The little 

 caterpillars remain sitting in thousands below the rings, which 

 cut off their way to the crowns of the trees. The composition 

 used should retain its fluidity for some time, but need not be 

 very sticky, as the caterpillars to be caught are so small. 



Large fires lighted at night in the forest to attract and burn 

 the moths have failed to do any good. In 1890, in the Bavarian 

 forests the moths were attracted by electric lights to the mouth 

 of a large funnel into which they were sucked by an exhaust 

 current of air produced by steam power. Large numbers 

 were collected by this method, and killed, but it cannot be 

 stated whether the utility of this proceeding is commensurate 

 with its expense. 



Low grease lands, as already described, page 300, for the 



