UNITED STATES DEPARTMENT OF AGRICULTURE 



BUREAU OF ENTOMOLOGY. 

 WASHINGTON. D C. 



FOREST ENTOMOLOGY II. 



April 18, 1916, 



Brief Information on 



GOTTONY MAPLE SCALE and ITS CONTROL. 



Character and Extent of Injury. 



The cottony maple scale attacks a great variety of trees and vines. Its 

 food consists of sap obtained by sucking from within the plant tissues. Occa- 

 sionally the insect appears in great numbers when it seems to injure shade and 

 other trees materially. 



Ssasonal History. 



This scale insect, even when present in great numbers, remains unnoticed 

 until about June when, at about the latitude of Washington, D.O., it is rendered 

 strikingly conspicuous by the large, white, cottony egg mass which appears at 

 that time at the end of the bcdy of the female insects. The eggs hatch In early 

 summer, though sometimes this hatching extends into August, and the young settle 

 upon the twigs and underside of leaves. In the fall the females migrate to the 

 twigs, where they remain unchanged through the winter, rapidly swelling in the 

 spring and forming the egg mass in early summer. It thus produces but one gen- 

 eration annually. 



Natural Control . 



Fortunately it is subject to destruction by a large variety of predaceous 

 and parasitic insects, which annually check it quite promptly, so that it is 

 rarely injurious in two consecutive years. The sudden appearance of the pe^x 

 is due to weather or other conditions unfavorable to its enemies. As soon as 

 such conditions pass away, the pest disappears. 



Remedies . 



Remedies are rarely necessary. Where occasion arises for their use, a 

 spray of dilute (summer strength) kerosene soap emulsion during the hatching 

 of the eggs (June and July) is certain to prove effective. The method of pre- 

 paring and applying this substance is given in the accompanying Brief. 



A. D. HOPKINS, 



Forest Entomologist. 



