Tent Caterpillar 147 



expected from San Jose scale. Treatment for Oyster Shell 

 or San Jose will keep this scale in check. 



San Jose Scale. This is the most destructive scale in- 

 sect that affects deciduous orchard trees. It lives on near- 

 ly all kinds of woody plants, and when left alone is capa- 

 ble of killing a tree in the course of a very few years. The 

 scales are very small, seldom larger than the head of a 

 pin, and with a conspicuous nipple in the center. Eggs are 

 never deposited, but the females give birth to living 

 3'oung, after reaching maturity at about five weeks of age. 

 Each female is capable of producing about 400 offspring. 

 The characteristic thing about San Jose scale is that it 

 causes the bark to turn red, especially the inner bark and 

 the shoots of some species of plants. Other kinds of scales 

 will cause a reddish appearance, especially on the fruit, but 

 when the reddish color of the inner bark is pronounced, 

 and the scales are circular in outline, it may quite likely be 

 San Jose. For certain identification it should be referred 

 to an experiment station entomologist. 



The most effective remedy for this insect is spraying 

 with full strength lime-sulphur solution during the dormant 

 period, using either the commercial brands or home-made 

 mixtures. Miscible oils are also effective, and when the 

 commercial brands of these are used, the directions ac- 

 companying them should be followed, as serious injury to 

 the trees can come from using these in too strong solu- 

 tions. During the summer an application of self-boiled 

 lime-sulphur has proven itself to be very effective in de- 

 stroying all of the young insects with which it comes in 

 contact, and in coating the branches so as to make it diffi- 

 cult for the young to find a place to settle. 



Other Scale Insects. There are a number of other scale 

 insects which attack orchard trees and shrubs, some of 

 which closely resemble the San Jose scale in appearance. 

 All of them are less destructive than the San Jose, and are 

 easily controlled when precautionary measures are taken 

 such as for the control of San Jose scale. 



Tent Caterpillar. The eggs of this insect are deposited 

 in masses in rows around the smaller twigs in mid-summer, 



