CHAPTER XXVII. 



SOME INSECTS INJURIOUS TO CITRUS FRUITS* 

 Scale Insects f 



THERE are many scale insects injurious to citrus fruit. Possibly 

 taken collectively they are the most important pests of this class of 

 fruit. Their importance is due in part to difficulties encountered 

 in control which do not operate in the control of scale insects on 

 deciduous trees. Dormant sprays, the main dependence for scale 

 control on the latter group of plants, are not available for use 

 against citrus scales. It will not be feasible to discuss all the im- 

 portant scales in detail here but the two natural groups, the 

 armored scales and the unarmored scales, will be discussed 

 separately. 



Armored Scales { 



There are several armored scales which are important pests of 

 citrus trees. Of these the most destructive is probably the Purple 

 Scale present in Florida and the other Gulf States and in Califor- 

 nia. 



This scale resembles the common oyster-shell scale of the 

 Southern States. It is found for the most part on citrus fruits and 

 is of world-wide distribution. It attacks leaves, twigs and fruit 

 and is often seen on fruit in northern markets. 



The California Red Scale or Orange Scale If is more important in 



*See H. J. Quayle, Bulletin 214, California Exp. Sta.; J. R. Watson, 

 Bulletin 148, Florida Exp. Sta.; W. W. Yothers, Farmers' Bulletin 933, 

 U. S. Dept. Agr.; C. E. Wilson, Quarterly Bulletin, State Plant Board of 

 Florida, Vol. II, No. 1, and various bulletins from the Florida Agr. Exp. 

 Sta., The State Plant Board of Florida, The California Agr. Exp. Sta., The 

 California State Commission of Horticulture and the U. S. Dept. of Agr. 



t Family Coccidce. See list of publications given above and special bul- 

 letins mentioned in connection with the different scales. 



j See previous reference. 



Lepidosaphes beckii Newman, See H. J. Quayle, Bulletin 226 California 

 Agr. Exp. Sta. 



![ Chrysomphalus aurantii Mask. See H. J. Quayle, Bulletin 222, California 

 Agr. Exp. Sta. 



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