CHAPTER III. 







DIASPIN^B Continued. 

 RAVAGES OF THE ARMORED SCALES- 



Bark-lice omnipresent in Orange Groves. In the foregoing pages an ac- 

 count has been given of all the species of Diaspinse known to attack 

 citrus plants in this country. The appearance, distinguishing char- 

 acters and habits of each have been set forth with sufficient clearness, 

 it is hoped, to render recognizable by orange-growers the different mem- 

 bers of this group of insect pests, the most destructive and formidable 

 with which they have to contend. It remains to consider the nature 

 and extent of the injuries they inflict and the conditions under which 

 the plant becomes liable to attack. 



It may be premised that in all countries where the Orange is exten 

 sively cultivated Scale-insects exist, and not seldom make their pres 

 ence known through the losses they occasion the fruit grower. From 

 time to time there may be sudden irruptions of Scale-insects, which, 

 like an epidemic, are wide-spread in their effects, and overrun a great 

 extent of territory. Such an invasion, as has already been shown, oc- 

 curred in Florida upon the supposed introduction of the Long Scale. " In 

 southern Europe also, where the Orange and the Lemon have been culti- 

 vated for centuries, the occurrences of scale epidemics have been re- 

 corded, one of which, in the iirst decade of the present century, prevailed 

 throughout the entire district along the shores of the Mediterranean, 

 from Italy to Spain, and spread consternation among the inhabitants, 

 who were dependent upon the produce of their lemon and orange groves 

 for support. 



At the present day, however, owing to a better knowledge of these 

 pests, the use of cheap and effective insecticides, and of effective instru- 

 ments for applying them, such wide-spread devastation by Scale-insects 

 need not bo feared. The omnipresence of the pest, however, compels 

 the orange-grower to be ever upon the alert if he would avoid loss of 

 growth in the young or of productiveness in the older trees. 



In Florida the greater part of these losses are caused by three Dias- 

 pinous scales : Mytilaspis glovcrii, the Long Scale ; Mytilaspis citricola, 

 the Purple Scale, and Parlatoria pergandii, the Chaff Scale. These three 

 insects are so universally distributed that it is safe to say no bearing 

 orange tree exists in southern and eastern Florida upon which one or 

 the other cannot be found. 



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