INSECT PESTS OF OHIO SHADE AND FOREST TREES 295 



THE ROSE SCALE 



(Aulacaspis rosae Bouche) 



Description. The female scales are almost circular, a little 

 less than one-eighth of an inch in diameter and usually snow-white 

 in color. The male scale is long and narrow with three ridges 

 running lengthwise of the body. The eggs are purple. Usually 

 the scales are found in masses at the base of the host instead of 

 being distributed evenly over the surface, those of the two sexes 

 being mingled. (See Plate L, Fig. 2.) 



Life history and habits. The winter is passed in the egg stage 

 and the young appear over a rather prolonged period, beginning in 

 late 'May or in June. 



Nature of work. While rarely fatal, this insect nevertheless 

 does considerable harm by way of weakening the host. Artificial 

 control measures, therefore, are necessary, particularly in parks 

 and other ornamental plantings in cities. 



Food plants. Roses, blackberry, dewberry, raspberry, mango, 

 myrtle, pear, sago palm and Tree of Heaven serve as hosts for this 

 species. 



Distribution. This insect is distributed probably over most of 

 the United States and is known to occur in many widely separated 

 parts of the world. 



Natural enemies. The rose scale is known to be attacked by 

 at least two hymenopterous parasites, Aphelimis diaspidis and 

 Arrhenophogus chionaspidis. 



Control. The sulphur sprays as well as the miscible oils applied 

 at dormant strength during the early spring before foliage starts 

 are known to be effective control measures for this species. As 

 has been shown previously, the infestation often is low down and 

 may be protected quite thoroughly by an accumulation of fallen 

 leaves, hence one should take the precaution to remove these before 

 spraying starts. 



THE COTTONY MAPLE SCALE 



(Pulvinaria vitis Linn.) 



Description. The cottony maple scale is among the most con- 

 spicuous of the group and on occasion may be classed among the 

 most destructive. The scale proper is unobtrusive, but the large 

 ovisac, snowy-white when first formed and later becoming soiled 

 and gray, makes the insect very noticeable. 



The body of the female scale insect varies greatly with the 

 season. In the spring it is insignificant in size and is difficult to 

 see because of its close color resemblance to the bark of the host. 



