376 A Practical Hand Book 



Menthol, 10 grains 

 Zinc oxidi, 2 drams 



Aq. calcis, 8 ounces 



Acid carbolici, 15 drop8 



To control the insect, use is made of the habit of the caterpillars 

 of wintering in colonies together in webs or nests at the tips of the 

 twigs, these being cut off and burned at any time during the 

 late fall or winter. When the caterpillars are feeding, either dur- 

 ing the early fall or in the spring, spraying with arsenate of lead is 

 a quite effective method of control. 



The Fall Web Worm. 



This insect feeds on a large list of shade trees as well as on fruit 

 trees, the elms, willows, poplars and butternuts being, perhaps, the 

 more favored food plants among the former group. 



The moth is very variable in appearance, in northern New Eng- 

 land greatly resembling that of the brown-tail moth, except that it 

 has no brown tail. Further south the wings may bear numerous 

 small, black spots. It flies during June, July and early August 

 and lays its eggs, several hundred in a cluster, on the underside of 

 a leaf. These eggs soon hatch and the caterpillars begin to spin a 

 web, under which they feed. This web is extended as they grow 

 and need more food, enclosing more of the leaves, until quite a 

 part or all of a branch may be thus enclosed. After feeding thus 

 for a month or more the caterpillars leave the web, and either in 

 the ground or in crevices of the bark of the tree spin their cocoons. 

 The moths may emerge from these cocoons the same year and 

 lay eggs for a second generation, the caterpillars of which will 

 feed the same fall, but in New England it is more usual for them to 

 pass the winter in the cocoon, the moths appearing the following 

 summer. 



As the caterpillars of this insect feed together under a web, it 

 is easy to cut off this and kill the caterpillars, particularly when 

 the webs first appear and are small. Burning the webs on the tree 

 is sometimes resorted to, but many of the caterpillars are liable to 

 escape, and the tree is liable to be injured by this method. Spray- 



