94 Farmers’ Bulletin 1169. 
summer. Usually by the time their presence is discovered they are 
already very numerous. They live and feed in colonies and: their 
feeding consists in sucking the juices from leaves. 
Remedies —A stiff stream of water, frequently applied, will rid 
plants of the red spider in many cases. Individual trees may be 
sprayed with lime-sulphur (p. 11-12) mixed with soapy water or 
kerosene emulsion (p. 12, 13). kerosene emulsion or miscible oil 
mixed with nicotine sulphate in the usual proportions should also 
give satisfactory results. Make at least two applications with a 
10-day interval between them, the first 
as soon as the mites appear. 
GALL-MAKING MITES.” 
Tow injurious —The galls made on 
shade trees by these microscopic ani- 
mals are most often located on the 
leaves or other tender part of the grow- 
ing plant and, while the affected parts 
may be badly misshapen or discolored, 
serious harm to the vitality of vigorous 
trees is rare. 
Ilow .recognized.—The mite-made 
gall is always open and the opening is 
Fic. 64—Common red spider fringed with hairy growth, or, in fact, 
Sais ce gah fede = the very gall may consist of but a 
larger or smaller clump of such hairs. 
In the later stages of development some of these galls assume red 
and other colors, all invariably turning brown after being deserted 
by the mites. 
[Tabits—The mites overwinter hidden under bud scales and prob- 
ably also bark scales, and start feeding and reproduction early in the 
spring, in known cases before the buds open. The number of genera- 
tions produced during the growing season by any given species is not 
definitely known, but evidently there are several of them. When the 
food supply on a given spot gives out the mites migrate to another, 
often covering whole leaves or deforming the buds of entire trees in 
the course of a season. Their eggs are laid on the surface of the 
affected area and the feeding is supposed to cause the irritation which 
produces the abnormal growth. No explanation is yet available for 
the characteristic gall made by each species of mite, even though pro- 
duced on the same plant. 
Remedies.—Thorough spraying of infested trees during the dormant 
season with a contact insecticide, like kerosene emulsion (p. 12-13) 
or miscible-oil solution, should well-nigh exterminate a bad colony. 
7 Family Eriophyidae. 
— Ss ee ee eee ee ee ee ee ee eee eee 
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