﻿OF THE STATE ENTOMOLOGIST. 97 



the higher lands of that country : further, that they make a nidus of 

 this tree, to the leaves of which they consign the few eggs in their 

 abdomen. Notwithstanding my high appreciation of his knowledge 

 regarding the different species of Phylloxera, I immediately wrote to 

 my friend that he must be wrong, as we have no Cherraes Oak in 

 America, and I had never found the winged Grape Phylloxera upon 

 any of our oaks, though I had frequently beaten it in August from 

 vines. From an examination of specimens which accompanied the 

 letter, I suggested that he had mistaken the European Oak species 

 iquercus Fonsc.) for the Grape species (vastatrix). Subsequent care- 

 ful studies by Balbiani and others, proved this suggestion to be cor- 

 rect. Yet M. Lichtenstein still believes that he not only found the 

 winged females of two species that infest the Oak there, but that 

 among them there were some of the Grape-vine species. In that 

 event, the following conclusions are inevitable: 1st, as the Chermes 

 Oak does not occur here, the winged Grape Phylloxera in America, 

 and in all countries outside the range of that oak, must make a nidus 

 of some other tree ; 2d, the young (progeny of the sexual individ- 

 uals) brought forth on such trees when they are far away from vine- 

 yards, must inevitably perish ; because they are not winged, and have 

 feeble power of locomotion. From the fact that I have beaten from 

 our Post Oak, a large winged Phylloxera answering to the descrip- 

 tion of PA. carycBGaulis Fitch, which makes a large, irregular, 

 smooth gall on the leaf-stalk of the Bitternut Hickory, and which 

 certainly does not inhabit oak trees, I am the more disposed to be- 

 lieve that chance individuals of the Grape species may also be found 

 on oaks,* and am thus forced to the following conclusions : The 

 winged females of Phylloxera (and the same will hold true of two 

 allied genera — Pemphigus and Eriosoma) are not drawn by instinct 

 to any particular plant, but are wafted about and will lay their eggs, 

 or, in other words, deliver themselves of their issue, wherever they 

 happen to settle. If this is upon their proper food-plant, well and 

 good ; the young live and propagate: if not, they perish. We should 

 thus have the spectacle of the species wasting itself to a greater or 



* This hap-hazard, wandering habit is well known to belong to several closely allied Aphidians, 

 and the winged female of Pemphigus vagabundus Walsh, which forms a large coxcomb-lilie gall on the 

 Cottonwood, and can breed on no other tree, is often found in the Fall of the year so abundantly on all 

 kinds of trees and shrubs — as every entomologist in the habit of "beating" is aware— that it was 

 named in consequence of this wandering habit. I have reason to believe that in Pemphigus as in Phyl- 

 loxera, the winged females give birth in the Autumn, after leaving their galls, to wingless sexual indi- 

 viduals whose issue must naturally perish on all ti-ees except Cottonwoods. 



ER— 7 



