COOK, THE RED SCALE 19 



The form and position of the six lobes at the end of this last segment, are 

 shown in Figure 14, as also the spine-like plates which fringe the segment. 

 The reproductive and anal openings are often visible, while the genital glands 

 or spinnerets — the centred circles — are grouped and arranged as seen in the 

 figure. The paragenital glands are not found in the red scale. 



The male when mature, as with all coccids, has two wings. This and its 

 form mais'e it curiously different from the female, or from its earliest self, 

 while it is yet under the sheltering scale. (Figure 15.) 



Figure 15. Male of Chrysomphalus aurantii 



The life history is as follows : The young may be produced in broods of 

 from twelve to seventeen each, and are being born continuously for several days. 

 We never see eggs except in the abdomen of the partially transparent female, 

 as the young are born alive. We see then that there may be several genera- 

 tions each year, and that they are enormously prolific. 



The red scale works on all of our citrus trees, on the rose, apple, peach, 

 apricot, and other rosaceous trees, on fig, olive, many palms, sago palm, oak, 

 svillow, euonymus, and not a few weeds. I have seen a stem of castor bean so 

 thickly covered with the red scale, as to hide the stem absolutely from sight. 



THE YELLOW SCALE. 



The Yellow scale is so closely related to the red scale, that scientists regard 

 it as a sub-species, only. It is Chrysomphalus aurantii citrinus. The scale 

 is less convex, not so regular at the margin, less distinctly red in color, slightly 

 more transparent, and the female adheres more tenaciously to the scale, than 

 does the female of the red scale. The most obvious characteristic of the yellow 

 scale, is ihat it rarely works on the twigs, but only on the leaves and fruit, 

 while the red scale anchors and sucks from twigs, leaves and fruit. The yellow 

 scale is more prone to change its position on the leaves, and so is more likely 

 to be indicated on the foliage, by yellow spots. While the vellow scale is not 

 generally regarded as so serious an enemy of the citrus grower as the red 

 scale, yet in many cases it is an enemy of no mean rank. Orchards near here 

 are badly injured by the yellow scale. 



