SB 

 818 

 C578 

 ENT 



NO. 64. 



ited States Department of Agriculture, 



BUREAU OF ENTOMOLOGY, 



L. O. HOWARD, Entomoloeist. 



THE COTTONY MAPLE SCALE. 



(Pulvinaria innumerabilis Rathvon.) 

 By J. G. Sanders, Assistant. 



The cottony maple scale {Pulvinaria innumerabilis Rathv.) at ma- 

 turity is the most conspicuous scale insect indigenous to the United 

 States, and lias received much attention from entomologists and horti- 

 culturists on account of its occasional abundance. It was described in 

 1854 by Dr. S. S. Rath- 

 von, of Lancaster, Pa., 

 who gave the pest a very 

 expressive and significant 

 specific name. Since 

 then over 60 articles and 

 references concerning this 

 species have appeared in 

 entomological literature, 

 besides hosts of others in 

 newspapers a n d • o t h e r 

 periodicals. Of special 

 worth is a monograph of 

 the species, worked out in 

 elaborate form by J. D. 

 Putnam, which was pub- 

 lished in the Proceedings 

 of the Davenport (Iowa) 

 Academy of N a t u r a 1 

 Sciences, p. 339 (1S79). 



More recently in Bulletin 22, new series, Division of Entomology, Dr.L.O. 

 Howard published a thorough treatise on " The Two Most Abundant 

 Pulvinarias on Maple," giving in detail the distribution, food plants, 

 and life history of the cottony maple scale and the nearly related maple- 

 leaf scale, illustrated by numerous figures of the various stages of each 

 species. 



Sporadic outbreaks of this scale insect in various parts of the United 

 States have been reported from time to time for many years past, but 

 in each case natural enemies have subsequently increased with sufficient 

 rapidity to effectually check its progress. Recently many reports of its 

 extreme abundance have come to us from the city of Chicago and 



Fig. I.— Pulvinaria innumerabilis: adult females in position 

 on twigs, with egg sacs— natural size i from How ard I. 



