REPORT OF THE ENTOMOLOGIST AND BOTANIST. 211 



Food Plants. — The list of plants upon which the San Jose Scale has been found as 

 a serious enemy is a very large one and may almost be said to include all deciduous 

 trees and shrubs, and it has also been found in Maryland by Prof. W. G. Johnson, upon 

 such unlikely plants as milk-weed (Asdepias) and crabgrass (Panicum). It is particularly 

 noted, however, that the San Jos^ Scale does not attack Conifers — pines, spruces, cedars, 

 &c. — and has not so far infested injuriously any of the citrus fruits, such as oranges, 

 lemons, &c., although it has been found on these trees, and in the case of one species 

 Citrus trifoliata was found in large numbers in New Jersey by Prof. J. B. Smith. 



The botanical order to which most of the food plants belong is the Rose family. 

 So far, T have seen specimens of this scale in Canada, upon the following trees : pear, 

 plum, peach, black currant, apricot, apple, Russian mulberry and Japanese walnut. 



So far as we know, the Forbes Scale has similar food habits, but Prof. Cockerell 

 says that A. ancylus, the Putnam Scale, differs somewhat. This last is especially a maple 

 species but will flourish on poplar, oak, etc. It does not seem to take very kindly to fruit 

 trees as a general rule. It also does well (probably best) in the Transition faunal zone, 

 whereas the San Jos^ Scale belongs to the more southerly Upper Austral. In Canada 

 both the Putnam Scale and the Forbes Scale have been found on plum, pear, apple and 

 cherry trees. 



" The manner of attack is different, more or less, in the various species under dis- 

 cussion. A. ancylus, on fruit trees, will be found upon the smaller branches, but in my 

 experience more or less scattered, rarely in any great quantity. A. perniciosus is found 

 largely upon the branches, becoming very abundant, covering and killing them. On the 

 young shoots the reddening effect is very marked, though ancylus will also produce 

 reddening. A. Forhesi, as seen on apple trees in Mesilla (N. Max.), occurs largely under 

 loose bark on the trunk, wintering there in numbers, and only invades the branches 

 in limited quantity. Thus there may be quite a lot of Forbesi on a tree without its 

 being noticed."— (T. D. A. Cockerell, Technical Series, Bull. 6, U.S. Div. of Ent., 1897.) 



" At first glance it is not easy to distinguish this species {A. Forhesi, the Forbes 

 Scale), popularly known as the Cherry Scale, from the San Jos^ Scale. The purplish tinge 

 of the bark is also quite conspicuous on some varieties of apple and pear where the Cherry 

 Scale has established itself. The general appearance of the last segment of the female 

 very closely resembles that of the San Jose Scale ; but it can readily be distinguished 

 from that species by the presence of spinnerets." — (Willis G. Johnson, Proc. 9th Ann. 

 Meeting, Ass'n Econ. Ent., 1897.) 



Means of Distribution. — It is thought probable that most scale-insects are distri- 

 buted while in the minute larval form, chiefly by means of larcjer insects and of birds. 

 Since the San Jose Scale has been so critically studied, this has been actually proved to 

 be the case with that species, the young larvae having been frequently observed crawl- 

 ing upon lady-bird beetles of several kinds, ants, and other insects which resort to the 

 trees durini,' the breeding season. Isolated colonies of scale-insects in the tops of other- 

 wise uninfested trees and in close vicinity to the nests of small birds have doubtless 

 originated in this way. It is stated that the larvae are also carried by the wind ; this 

 seems difiicult to understand, but has been proved by Mr. W. G. Johnson in Maryland. 

 This insect may also undoubtedly be distributed by means of farm implements, domestic 

 animals and workmen attending to orchards. 



Much has been said about the danger of distributing the San Jos^ Scale through the 

 sale of infested fruit ; but, after considering the matter very carefully, I must still differ 

 in opinion from many good entomologists who think that there is great danger from 

 this cause. Fruit badly infested by the scale is generally disfigured too much to be 

 marketed, and upon fruit which is not sufficiently injured to be condemned for th-e 

 market the chances of the scale-insects surviving a long journey after the fruit is 

 removed from the tree, packed and shipped, and then of its being peeled and the peel- 

 ings thrown out in an orchard or near enough to a tree for the young larvae to infest it, 

 are so slight that I cannot even see the necessity of considering this danger. Further, 

 I have failed to hear of a single instance where infestation could be attributed to such 

 a cause, but it would, of course, be well, should any one detect the scale upon imported 

 f luit, to be careful to burn all peelings and not throw them out in a yard or garden 

 8a— 14^ 



