NOTES ON COCCIDAE I 



E. o. EssiG. 



Aspidiotus hederae 



IVY SCALE^ OLEANDER SCALE, LEMON PEEL SCALE. 



Perhaps there is no other scale in this locaHty which utilizes more plants 

 for food than this one. From the various names given it we may conclude 

 as to the principal host plants. It is found very thick on English Ivy. There 

 are few such plants in this district which are not infested with it. So to many 

 it is known as Ivy Scale. But on oleander it seems to thrive best. Not 

 infrequently we find it so thick as to completely cover the entire surface of the 

 leaf. It is found on many of the domesticated plants in the gardens and seems 

 to feed on almost anything. In this county it has done little or no damage 

 because as yet it has not taken to the citrus trees. However, this is not the 

 case in all other localities. Figure 8 shows this scale infesting a lemon. This 

 and many other specimens were obtained from P. E. Smith, Horticultural 

 Commissioner of Ventura County. The picture tells the story. There it is 

 known as the Lemon Peel Scale, and is a very bad pest. Perhaps it may never 

 be so here, but who knows ? It takes a long time to reveal all the character- 

 istics of some of the scales. In new localities they may struggle along for years 

 before they become acclimatized and do any damage. Because this insect 

 has done no harm here to the citrus industry in the past is no proof that it 

 will never do so. Anyway its record in other places stamps it as an unwelcome 

 visitor. 



Chrysomphalus citrinus 



YELLOW SCALE. 



The opinion has generally been held by most entomologists that when 

 an armored scale once settled and secreted her shell, she never moved 

 again from her resting-place. A very interesting thing has just come to 

 notice in regard to the yellow scale, which may throw some new light upon 

 this question. After examining countless numbers of leaves infested with 

 this scale it appears that the adult scale does move to a slight degree, in some 

 cases almost an inch, between the time she first secretes her shell until death. 

 Where this scale feeds no one can fail to notice the light yellow traces produced 

 upon the leaf. In not a few cases there is left a distinct scar along the middle 



