34 



this tree were very thickly infested by the scales, indicating that the 

 tree is perfectly congenial to their tastes and requirements. 



In the above-mentioned account I stated the fact that at that time 

 no insect was known to attack these scales, but since this was written 

 I have bred from them numerous specimens of a small Chalcid fly, 

 known as Coccophagus lecanii Fitch. These attack only the younger 

 scales, and only one of the parasites infests each scale, causing the lat- 

 ter to assume a more convex, much smoother form than when not para- 

 sitized, and the entire upper portion of the parasitized scale becomes 

 black. 



The Bkown Apricot Scale. 



(Lccanium sp.) 



In the Santa Clara Valley, south of San Francisco, occurs a species 

 of Lecanium which is sometimes very destructive to various kinds of 

 deciduous trees. On the 21st of March of the present year I received 

 specimens of these scales from Mr. F. M. Eighter, an extensive grower 

 of deciduous fruits located in the above-mentioned valley. The scales 

 were of two sizes, representing two different generations, the old dead 

 and dry females and the nearly half-grown young ones. A careful ex- 

 amination of these specimens convinced me that while they were evi- 

 dently closely related to the Frosted Scale of the preceding chapter, 

 still they evidently belonged to a distinct species. The more marked 

 differences consisted in the smaller size of the adult females, the fact 

 that they never became covered with a whitish powder, and the further 

 fact that the younger ones are destitute of the submarginal row of long 

 bristles which occur in the young of the Frosted Scale. 



In the letter which accompanied these specimens Mr. Eighter writes 

 as follows concerning them : 



I send you by today's mail specimens of the Brown Apricot Scale, so called, not- 

 withstanding they infest prune trees as much or more than apricot. They are also 

 found on peach, pear, apple, and cherry, hut principally on apricot and prune. 

 * * * I think they are not the same as the Brown Scale you mention ; they are 

 never covered with a white powder. 



Thinking that perhaps the submarginal bristles may have existed in 

 perfect specimens of the young scales but had been accidently broken 

 off of the specimens sent me through the mails, I requested Mr. Eighter 

 to examine the young scales fresh from the tree and ascertain if these 

 submarginal bristles existed upon them; and under date of April 18, 

 1891, he writes me as follows : 



I have a microscope of very high magnifying power, and have carefully examined 

 both the young and the full-grown scales, and find that neither of them are pro- 

 vided with bristles around the edge of the body. Nor can I find any as large as you 

 mention, i. e., seven twenty-fifths of an inch in length; the largest I can find meas- 

 ure seven thirty-seconds of an inch in length. 



Again, under date of May 12, he writes as follows: 



The Brown Apricot Scale seems to have completed its work. Its eggs are laid, 

 and it is seemingly wholly inactive. 



