330 NEW YORK STATE MUSEUM 



Lochhead, William. San Jose and other scale insects, Ont. dep't 

 agric. Toronto. 1900. p. 37-38 (typical form not in Ontario, brief 

 notice). 



Reh, L. Scale insects on American fruit imported into Germany 

 [English abstracts] U. S. dep't agric. div. ent. Bui. 22, n. s. 1900. 

 p. 79, 80 (common on fruit, but immature). 



Cherry scale insect 



Aspidiotiis forbesi Johnson 



PLATE 6 



This species is the rarest in New York state of those noticed in detail 

 in this bulletin. It has been known to science but five years, having 

 been described by Prof. W. G. Johnson in 1896. 



Previous history. Prof. Johnson characterized this species as the 

 most dangerous scale insect then established in Illinois. It was first dis- 

 covered on Morello cherry, and later he found that it was generally dis- 

 tributed over the state. It also occurred on wild cherry, and, on account 

 of its apparent partiality for that tree, the above common nam.e was pro- 

 posed. Prof. Johnson states that it was not uncommon in 1896 to find 

 seven and eight year old cherry trees Hterally covered with the pest, and 

 that a- number were killed by it. Prof. Forbes, state entomologist of 

 Illinois, writing of this and allied species in 1898, states that " they are 

 of no extraordinary interest to the fruit growers, none of them being either 

 as abundant or as destructive when present as the commonest of the na- 

 tive orchard scales, the so called scurfy scale of trie apple, Chionaspis 

 f u r f ura". It will probably prove no more injurious in this state than 

 in Illinois. 



Description. This scale insect is closely allied to the three preced- 

 ing forms. Its rarity in the state has prevented a thorough study of its 

 external characteristics. A mass of the adult scales, so far as observed 

 by me, is much lighter in color than that of either of the two preceding 

 species and usually hghter than a similar mass of San Jose scale, because 

 the latter is almost sure to include a number of the dark gray or nearly 

 black young. The general appearance of an infested twig is shown in 

 figure 6, and a group from this is enlarged in figure 7. The adult female 

 scales are rather flat, yellowish gray, and about y^ inch in diameter and 

 with a reddish, eccentric larval skin or exuviae. The color and general 

 appearance is well shown in figure 7 and in greater detail in figure 8, 



