INSECTS AFFECTING OHIO SHADE TREES 177 



<~ , This species resembles the scurfy bark 



7 he Rose Scale. . , 



Aulacaspis rosae Bouche lous f thou ^ h the ^ eneral . appearance of 



the infestation as a rule is of a whiter, 



fluffier nature. ("Plate 2, Fig-. 1.) The life history is practically 

 the same as that of the scurfy scale, and the winter applications of 

 the lime-sulfur wash are effective. Scalecide in 5 percent solution 

 was not successful. 



Roses, blackberries and raspberries are most commonly at- 

 tacked. Rosa rugosa is irore severely attacked than other roses, but 

 even with this variety, the writer has observed very few instances 

 where the plants were killed. 



f 7 This species occurs upon the elms 



The Elm Scurfy Scale. A , ,. - T ., 



Chionas-pis Americana Johns. and the lindens. It resembles very 



closely the scurfy bark louse, in fact 



it is quite likely that for many years it was confused with this insect. 

 The life history is the same. In the writer's observation, however, 

 the elm scurfy scale is not so evenly distributed over the host plant 

 as is the scurfy, the lower side of the branches being" more subject 

 to infestation. 



Lindens moderately infested with this scale were sprayed with 

 lime-sulfur, April, 1907. Observations made during- the ensuing 

 season indicated that the results of the application were all that could 

 be desired. In the vicinity of the lime-sulfur sprayed trees, other lin- 

 dens were sprayed with 5 percent scalecide. Little good seemed 

 to result from this treatment, as the scale developed in abundant 

 quantities during- the following- season. 



Contact sprays applied at hatching- time are effective against 

 this species, but as has been indicated in the case of other scales 

 with a similar life history, they are hardly practicable. 



TO yvj ^/o/ During the early summer months 



The Cottony Maple Scale, ... *" 1 . -1 j . 



Pulvinaria innumerabilis Rathv. thls scale 1S easll y detected by the 



presence of a white, cottony mass 



which the insect exudes from beneath the covering scale. (Plate 2, 

 Fig. 2.) Within this mass may be found the eggs, the number 

 varying from a few hundred to two thousand. Hatching occurs 

 during the early summer and the young migrate to the leaves or to 

 the tender young growth, where they settle and begin feeding upon 

 the sap of the tree. Meanwhile a thin scale covering forms over 

 each individual, which with the growth of the insect enlarges and in 

 time turns brown. Before the leaves fall most of the insects migrate 

 to the branches and trunk, where they settle preparatory to passing 

 the winter in their partially grown condition. With the coming of 

 spring maturity is soon reached and the cottony mass already de- 

 scribed appears. 



