242 HORTICULTURE FOR SCHOOLS 



attacking species. The citrus red-spider is also a web-spinner 

 and is found commonly on citrus trees, but occurs as well on 

 pears, apples, peaches, and certain other kinds of deciduous 

 fruit-trees. 



During the summer time, the eggs of both the citrus red- 

 spider and the two-spotted mite may be found on the surface 

 of infested foliage. The eggs of the former are red in color 

 as are also those of the brown mites, while the eggs of the 

 two-spotted mite are white and appear as little pearl-like 

 objects, very inconspicuous on the surface of the leaf. 



353. Control of mites. In the case of brown mite and 

 citrus red-spider, each of which spends the winter in the egg 

 stage, control may be effected by treating thoroughly with 

 lime-sulfur at the strength of one gallon of the liquid to ten 

 gallons of water in the early spring as the buds are swelling 

 on the deciduous fruit-trees. In the case of the two-spotted 

 mite, which does not spend the winter season in the egg stage, 

 this treatment would be of no avail. As a substitute for 

 lime-sulfur, any of the oil emulsions may be used, application 

 being made at the same time as with the former. 



During the summer, when active feeding is taking place, 

 control may be effected by an application of sulfur in some 

 form. Atomic sulfur is now very commonly and very suc- 

 cessfully used in red-spider control. Since all species are 

 killed by sulfur, this may be considered the standard remedy. 



354. Blister-mites. In addition to the so-called red- 

 spiders, a group known as blister-mites affect some fruit- 

 trees. The most common species, one which is distributed 

 widely through the different states of the Union, is the pear- 

 leaf blister-mite. 



This little pest winters beneath the scales of pear buds, 

 crawling out when the buds begin to unfold in the spring, and 

 begins to feed just as soon as growth appears. There is a 

 characteristic reddish-colored blister-like patch which forms 

 wherever this mite attacks the foliage. Feeding takes place 



