INSECT PESTS OF OHIO SHADE AND FOREST TREES 279 



Distribution. Like the gipsy moth the brown-tail is widely 

 distributed in Europe. In the United States it occurs in all the 

 New England states, the infested area being considerably greater 

 than that occupied by the gipsy moth. Northward, it has spread 

 to Nova Scotia and New Brunswick. 



Natural enemies. As with the gipsy moth, the brown-tail is 

 well supplied with natural enemies in its native habitat where its 

 ravages are greatly minimized by them. With this species also, 

 the Federal Bureau of Entomology is making every effort to intro- 

 duce and establish these natural controls. While discouragements 

 have been encountered, the work is meeting with a satisfactory 

 measure of success. 



For a list of the natural enemies of the brown-tail moth and a 

 report of the work of introduction into the United States, the reader 

 is referred to the publication of Howard and Fiske (38) cited in 

 connection with the parasites of the gipsy moth. 



Control. When practicable of application, such as in orchards 

 and on small trees, the collection and destruction of the conspicuous 

 hibernating nests during the winter months is recommended. On 

 large trees and over extensive areas, spraying with poisons is more 

 practicable. The work should be done in August when the cater- 

 pillars are small in order to yield success. At this time arsenate of 

 lead used at the rate of 8 pounds of paste to 100 gallons of water 

 is sufficiently strong. 



Spraying in the spring when the larvae begin feeding is not 

 so successful, since at that time the insects are larger and more 

 difficult to poison; and at the same time, since they feed upon the 

 expanding buds, very little surface is present for the spread of the 

 poison. If, however, the fall spraying or collecting the winter nests 

 has not been done, the spring application is advised but the poison 

 solution at that time should be stronger. No less than 10 to 12 

 pounds of paste arsenate of lead should be used to 100 gallons of 

 water. 



