HANDBOOK ON INSECT ENEMIES OF FLOWERS AND SHRUBS 81 



from the under sides of the leaves. 

 This insect attacks chiefly rose and 

 apple, although it also feeds on other 

 shrubs and trees. It is found on the 

 foliage most of the summer; therefore 

 all stages are usually present. The 

 adult (fig. 137) is about Y% inch long, 

 narrow, greenish yellow, and very active. 

 The species overwinters in the egg stage 

 under the bark of the plant, and the 

 whitish nymphs hatch about the begin- 

 ning of May. The other species men- 

 tioned in the discussion on leafhoppers 

 (p. 10) may at times feed on and injure 

 roses. 



Treatment and prevention. — See 

 treatment for leafhoppers (p. 10). 



T 



Wsm 





Figure 137. — Rose leafhoppers on the 

 under side of a leaf. About twice 

 natural size. 



Rose Scale 



Not infrequently rose bushes are 

 found completely encrusted with a snow- 

 white substance. On close examination 

 this material proves to be composed of 

 very small scalelike insects known as 

 the rose scale (Aulacaspis rosae 

 (Bouche)), thicklv massed or clustered 

 on the twigs (fig.' 138). The female 

 scales are nearly circular, dirty white, 

 with an orange-colored dot in the center. 

 The males are much smaller, long and 

 narrow, and snow white. These in- 

 sects not only spoil the appearance of 

 rose bushes, but their sucking of the 

 vital sap reduces the vigor and health. 

 Raspberry and blackberry canes are 

 often attacked. 



Figure 138. — Twigs infested with the 

 rose scale. 



Treatment. — Remove and burn all 

 heavily infested canes that can be 

 spared. Spray with white-oil emulsion 

 (p. 100) after the leave sdrop and again 

 in early spring before the buds begin to 

 swell. For light infestations, spraying 

 in early spring with a strong solution of 

 fish-oil soap or common soap (p. 100) 

 will suffice. Lime-sulfur may be used 

 if the plants are not located near brick 

 work or buildings, since it may soil the 

 objects with which it comes in contact. 



Rose Galls 



Certain species of insects produce 

 swellings or galls on roses. One of these, 

 the mossy rose gall (Diplolepis rosae 

 (L.)), forms a large, globular, fibrous 

 mass, about an inch or more in diame- 

 ter, on the twigs (fig. 139) early in the 

 season. The galls are light green at 

 first and later they turn purplish brow n 

 and are covered with a thick mossy 

 growth, from which they derive their 

 name. The inside is separated into 

 individual cells, which contain the larvae 

 of the tiny gall wasp. There is only one 

 brood a season. The dried brown galls, 

 if not removed, will remain on the 

 bushes. 



Another species, the rose root gall 

 (Diplolepis radicum (O. S.)), while more 

 often found on wild roses, sometimes 

 attacks cultivated roses at the base or just 

 below the ground. The galls (fig. 140) 

 are rather conspicuous, some reaching a 

 diameter of 1 or 2 inches. The inside 

 is packed full of cells. The adults are 



