536 TPIE MONTHLY BULLETIN. 



CALENDAR OF INSECT PESTS AND PLANT 



DISEASES. 



By E. J. V'OSLER. 



[Lender the above heading the author aims to give brief, popular descriptions and 

 methods of controlling insect pests and plant diseases as nearly as possible just prior 

 to or at the time when the suggestions given should be cairied into effect by the 

 growers. ] 



DECIDUOUS FRUIT INSECTS. 



The San Jose Scale. 



The San Jose scale occurs throuinhout the entire state. It attacks the 

 almond, plum, prune, peach, pear, and apple. The female scales are 

 light gray in color, circular in form, and less than one eighth inch in 

 diameter." Trunks and branches covered with the scale have a gray and 

 rough appearance. The scales, however, are most easily detected on 

 the fruit, which becomes spotted with small red circles which form 

 around the scales. Scale infested fruit is unfit for the market. The 

 millions of the tiny scales suck out the juices of the host and poison the 

 tissues. 



To control, use commercial lime-sulphur solution, 1 part in 9 to 11 

 parts of water, during the dormant season. Spray thoroughly, using 

 a driving spray at a pressure of fr(mi 150 to 200 pounds. 



The Italian Pear Scale. 



The Italian pear scale occurs in Alameda and Napa counties and also 

 in the Santa Clara Valley. The host plants are the pear, plum, apple, 

 peach, and currant. The female scale is dark gray in appearance, 

 circular or oval in form, and less than one eighth inch in diameter. It 

 closely resembles the San Jose scale and is often mistaken for it. It 

 works to a large extent, however, under the moss on the trunks and 

 larger limbs, and therefore is not easily noticed. 



Spray with distillate oil emulsion at 6 per cent strength, crude oil 

 emulsion at 12 per cent strength, commercial lime-sulphur solution, 1 

 part to 9 parts of water, during the dormant period. 



The European Fruit Scale. 



The brown apricot scale, or European fruit scale, as it is often called, 

 is common throughout the deciduous fruit growing sections of Cali- 

 fornia. Its favorite hosts are the prune, plum, apricot, almond and pear. 



The adults of this scale are from ^ inch to fV inch in length, about i 

 inch high, yellowish brown in color, sometimes marked with black. The 

 older scales are shiny, convex and oval. 



In the early spring one will find the under sides of limbs and twigs 

 thickly encrusted with this scale. It is at this time that they begin to 

 develop into the adult form, after which they soon begin to deposit 

 large numbers of eggs. The young scales emerge, settle on the leaves 

 and begin to suck out the sap. They excrete a sticky substance known 

 as honeydew. This honeydew. on infested trees, covcm-s the foliage, fruit 



