6 MISSOURI AGRICULTURAL EXPERIMENT STATION BULLETIN 176 



CONTROL. Since the pest thrives best in weak or dying trees or limbs, keep 

 all orchard primings removed from the orchard. In the nursery avoid the use 

 of left-over trees for filling draws and the like alongside the growing stock. 

 Remove and burn trees which are too seriously injured by the pest to be saved. 

 In the orchard promptly prune out affected limbs and destroy them. The 

 regular summer sprays with arsenate of lead and lime-sulphur for fruit insects 

 will tend to repell this pest where spraying is thoroly done. 



a bed 



FIG. 5. Shot-hole Borer; a, Adult; b, side view of same; c, pupa; 

 d, borer; all enlarged. (From U. S. Dept. Agr.) 



San Jose Scale (Aspidiotus perniriosus). This imported scale insect 

 is the most notorious one that attacks fruit trees. It came from the Orient 

 some thirty years ago and has been in this state for about twenty-five years. 

 It had much to do with the establishment of State and Federal Plant Inspec- 

 tion Services and hastened the day when regular orchard spraying was abso- 

 lutely necessary. In thirty years it has destroyed thousands of orchards and 

 has cost nurserymen millions of dollars. 



It is a sap-sucking insect which secretes over its back a protecting scale or 

 armor. The female gives birth to the young and in a day or two they insert 

 their beak, begin to extract sap and to secrete the protecting armor. The fe- 

 males never move from the point where they begin to feed, tho later the males 

 emerge as small two-winged insects. In from thirty to forty days the insect 



FIG. 6. San Jose Scale; portion of peach limb showing scale incrusting it. 



Enlarged 



