REPORT OK THE SOCIETY ^^ 



DOUBLE-HOST APHIDS. 



Following is a partial list of double-host Aphids: — 



Chermes abieticolens on spruce = Chermes pinifoliae on white pine. 



Pemphigus tesselatus Fitch on alder. . . . = Pemphigus acerifoliae Riley on maple. 

 Pemphigus balsamiferae on cottonwood = Pemphigus betae on beets. 



Eriosoma pyricola on pear =Eriosoma pyricola on elm. 



Eriosoma lanigera on apple = Eriosoma americana in part on elm. 



Eriosoma americana on plum = Eriosoma americana on Juneberry. 



Eriosoma ulmi on English Elm ...... = Eriosoma fodiens on currant. 



Hyalopterus arundinis on plum =H. arundinis on reed grass, cat-tail. 



Phorodon humuli on plum =P. humuli on hop. 



Aphis avenae on apple =A. avenae on oats, cat-tail etc. 



Aphis sorbi on apple =A. sorbi on plantain. 



Aphis viburnicola on snowball = 



Aphis pruni on plum = Aphis cardui on thistle. 



Aphis nerii on oleander : . . . . = A. lutescens on milkweed. 



Aphis bakeri apple and hawthorn = Aphis bakeri on clover. 



Aphis brevis on apple and hawthorn . . . = Aphis brevis on clover. 



Aphis enonymi on snowball and burning = Aphis rumictis on bean and dahlia. 



bush. 

 Macrosiphum illinoiensis on Viburnum =M. illinoiensis on grape. 



prunifoiae. 



Macrosiphum solanifolii on rose =M. solanifolii on potato. 



Macrosiphum granarium on grains, rose =M. granarium on cat-tail. 



etc. 



Aphis prunorum Dob. on plum = Rhopalosiphum nymphaeae on Nym- 



phaea, Alisma, Sagittaria, Typha. 



Rhopalosiphum ribis on Ribes = R. lactucae on Sonchus. 



Rhopalosiphum caprea on willow = R. capreae on Umbellife rae. 



Myzus ribis on Ribes =M. galeopsidis on galeopsis. 



Myzuscerrasi on cherry =M. cerasi on Lepidium. 



Rhopalosiphum pasticaceae on Lonicera = R. pastinaceae on Pastinaca. 

 Hormaphis hamamelidis Fitch on witch = Hormaphis hamamelidis on birch. 



hazel. 

 Hamamelistes spinosus Shimer on witch = Hamamelistes spinosus Shim on birch. 



hazel. 



Tetraneura graminis on Ulmus =T. graminis on Leersia. 



Thecabius populiconduplifolius on pop- =T. californicus on Ranunculus. 



lar. 



