206 MANUAL OF GARDENING 
the yellow leaf-hoppers feed on the leaves. Spray, whenever necessary, 
with kerosene emulsion, diluted with 6 parts of water, or whale-oil or 
any good soap, 1 lb. in 5 or 6 gal. of water; or a tobacco extract. 
The rose-chafer is often a most pernicious pest on roses, grapes, and 
other plants. The ungainly, long-legged, grayish beetles occur in sandy 
regions and often swarm into vineyards and destroy the blossoms and 
foliage. Spray thoroughly with arsenate of lead, 10 Ib. in 100 gal. of 
water. Repeat the application if necessary. (See under Rose on 
page 395.) 
San José scale. — This pernicious scale is nearly circular in outline 
and about the size of a small pin head, with a raised center. When 
abundant, it forms a crust on the branches and causes small red 
spots on the fruit. It multiplies with marvelous rapidity, there being 
three or four broods annually in New York, and each mother scale may 
give birth to several hundred young. The young are born alive, and 
breeding continues until late autumn when all stages are killed by the 
cold weather except the tiny half-grown black scales, many of which 
hibernate safely. Spray thoroughly in the fall after the leaves drop, 
or early in the spring before growth begins, with lime-sulfur wash, or 
miscible oil 1 gal. in 10 gal. of water. When badly infested, make two 
applications, one in the fall and another in the spring. In case of large 
old trees, 25 per cent crude oil emulsion should be applied just as 
the buds are swelling. Lime-sulfur is now the standard remedy. 
In nurseries, after the trees are dug, fumigate with hydrocyanic 
acid gas, using 1 oz. of potassium evanide for every 100 cu. ft. of 
space. Continue the fumigation from one-half to three-quarters of 
anhour. Do not fumigate the trees when they are wet, since the pres- 
ence of moisture renders them liable to injury. 
Tent-calerpillar.— The insect hibernates in the egg stage. The 
eggs are glued in ring-like brownish masses around the smaller twigs, 
where they may be easily found and destroyed. The caterpillars 
appear in early spring, devour the tender leaves, and build unsightly 
nests on the smaller branches. This pest is usually controlled by the 
treatment recommended for the codlin-moth. Destroy the nests by 
burning or by wiping out when small. Often a bad pest on apple trees. 
Violet gall-Ay. — Violets grown under glass are often greatly injured 
by a very small maggot, which causes the edges of the leaves to curl, 
