IMPLEMENTS USED. 



125 



egg-cluster when treated is surrounded with a ring of white 

 paint to prominently mark its location, (see Plate XIX.). 



The most recent preventive method used in Europe is the 

 covering of the eggs with a coat of tar or with raupenleim, 

 a substance much used to prevent caterpillars from ascending 

 trees. Though these substances, as well as varnish, have 

 been used here experimentally with some success, the use 

 of creosote oil is much to be preferred, as it penetrates the 

 eggs at once and destroys their life, while the other sub- 

 stances merely prevent the larvee from emerging, provided 

 the covering remains intact. 



Destroying the Eggs by Gases. 



Experiments were made to find some agent other than fire 

 that would destroy the eggs in hollow trees. A little bro- 

 mine or chlorine poured into the hollow of a tree, branch or 

 stump will destroy all animal life within the hollow if the 

 cavity can be thoroughly sealed or closed. 



Implements used in the Search for the Eggs. 

 Each inspector is provided with a small binocular glass of 

 opera size, which he carries in a leather case suspended by a 

 strap from his shoulder. By means of this he is able while on 

 the ground to distinguish the eggs of the gypsy 

 moth from those of other insects when attached 

 to the higher limbs of large trees. This glass 

 is useful in dark or cloudy weather, as well as 

 in the morning or evening twilight of the short 

 winter days. Its use often renders tree climb- 

 ing unnecessary, and thus much time is saved. 

 Each man is provided with a pocket mirror so 

 constructed that the glass, if broken, can be 

 quickly and cheaply replaced (Fig. 5). This 

 is extremely useful in many ways during the 

 search for eggs. Whenever the lower rail of a 

 board or picket fence is so near the ground that 

 its under side cannot be seen, a mirror placed at 

 a slight angle underneath will reflect the whole 

 lower surface for several feet, and show any 

 egg-clusters which may be deposited there. 



