90 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



ance furnished our survey by the men associated with the Bureau of 

 Plant Industry, and workers in other states, who came to our assistance 

 on very short notice. It is our purpose and desire to exert the utmost 

 effort in every way possible to prevent the further spread of this most 

 serious known potato disease, and considering the rather favorable 

 conditions under which the disease occurs (in isolated villages without 

 intervening cultivated territory) v/e have reason to believe that we can 

 ultimately eradicate the pest. No expense and effort is too great, in 

 consideration of the extremely dangerous and destructive nature of 

 this long-lived soil-infecting plant disease, coupled with the fact that 

 it is threatening the most important vegetable food crop in our United 

 States. 



AN EUROPEAN SCALE INSECT BECOMING A MENACE IN 



PENNSYLVANIA 



By J. G. Sanders, Economic Zoologist, Harrisburg, Pa. 



It seems desirable to call the attention of our entomologists and hor- 

 ticultural inspectors to a scale insect, probably a native of China, later 

 introduced to Europe, which in recent years has become established in 

 Pennsylvania. This soft scale insect, Lecanium prunastri Fonsc, 

 has been recorded a number of times from various places in Central 

 Pennsylvania at rather widely scattered points, but principally from 

 the south central and warmer section of the state. 



Its principal host plants are peach, sweet cherry and apricot, and 

 within the past two or three years this pest has become sufficiently 

 abundant in a few localities to cause genuine damage and alarm to the 

 fruit growers. Some branches of peach become so thickly covered 

 with the scale, that they are badly dwarfed, and ultimately killed. 

 However, in the orchards where the customary winter dormant spray 

 with lime-sulfur wash is practiced, the scale has not assumed dangerous 

 proportions. 



In general appearance, in the summer season, it is not dissimilar 

 from the common terrapin scale, although on closer inspection, it will 

 be seen that the adult female scales are almost globular in form, and 

 usually deep, chestnut red colored, usually closely massed on a tree 

 when abundant. Not infrequently a large number of the small, glassy 

 white male scales are associated with the larger round female scales. 

 The accompanying figures will show some of the principal distinguish- 

 ing characteristics of this scale, in comparison with our other common 

 Leeaniums (PL 3, fig. 1.) 



As far as records of the United States Bureau of Entomology 

 indicate, the scale has never been reported except from the State of 



