. The American entomologist. Entomology. 82 THE AMEEICAN ENTOMOLOGIST. two other such, species that infest respectively the Hickory and the Oak. Whether any or all of these species likewise infest the roots of the trees upon which the)' occur, remains to be ascertained. Bnt certainly they can never emi- grate on to the Apple; for the Apple, the Elm, the Ash, the Dogwood, the Hickory, and the Oak, all belong to different botanical families; and no Plant-louse that lives upon a plant be- longing to one botanical familv, can live when transfen-ed to a plant that belongs to a different botanical f
. The American entomologist. Entomology. 82 THE AMEEICAN ENTOMOLOGIST. two other such, species that infest respectively the Hickory and the Oak. Whether any or all of these species likewise infest the roots of the trees upon which the)' occur, remains to be ascertained. Bnt certainly they can never emi- grate on to the Apple; for the Apple, the Elm, the Ash, the Dogwood, the Hickory, and the Oak, all belong to different botanical families; and no Plant-louse that lives upon a plant be- longing to one botanical familv, can live when transfen-ed to a plant that belongs to a different botanical family. Even when two plants belong- to different geitera of the same botanical family, it is not often that the same Plant-louse will live indifferently upon either; and frequently the same Plant-louse will not even live indifferently upon two plants that belong to the very same botanical genus. "We have a remarkable exam- ple of this last fact in the common Currant Plant-louse, which swarms in almost every gar- den upon the Currant, and yet was never known to shift its quarters on to the Gooseborrj'—a species that belongs to the very same genus (Sibes) as the Currant. Indeed so far is this from being the case, that nobody ever saw Plant-lice of anj^ kind whatever infesting the Gooseberry. [Fig. 70.]. Colors—(6) diill lead color; (c) black. Fig. 70, 6, shows the Apple-root Plant-louse in the larva state, with the usual Avooly matter attached to its back. Fig. 70, c, shows the same insect in the perfect or winged state, with the wooly matter all removed.* On comparing » We annex the technical description of this Plant-louse, drawn up from the recent specimen. The AppL35-itooT Plant-lodse (Eriosomrt pyri, Fitch.) Black. AntenniE2-5ths aslong as thebody, joints 1 and2al- most confluent, short and robust; joint .3 fully J the entire length of the antenna; joints4—0 snbequal, 5 a little the long- est, 6 a little the shortest. (Fig. 70, /, that of the Winged- louse; y, th
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectentomology, bookyear1
