298 Wisconsin Academy of Sciences, Arts, and Letters, 
Populus alba. 
Aphis longirostris Fabricius. 
Arctaphis populi Linnaeus. 
Asiphum tremulae Linnaeus. 
Chaitophorus leucomelas Koch. 
Chaitophorus salicti Schrank. 
Chermes populi Del Guercio. 
Pachypapa marsupialis Koch. 
Pachypapa vesicalis Koch. 
Pemphigus filaginis Boyer. 
Pterocomma populea Katlenbach. 
Sehizoneura passerinii Signoret. 
Populus angustifolia. 
Chaitophorus populicola Thomas. 
Cornaphis populi Gileltte. 
Schizoneura populi Gillette. 
ThecaMus populi-monilis Riley. 
Populus balsamifera. 
Anuraphis populi Del Guercio. 
Chaitophorus candicans Thomas. 
Chaitophorus populicola Thomas. 
Chaitophorus populifoliae (Oestlund) Davis. 
Mordwilkoja vagadunda Walsh. 
Pemphigus halsamiferae Williams. 
Pemphigus gravicornis Patch. 
Pemphigus popularia Fitch. 
ThecaMus populi-conduplifolius Cowen. 
Pamphigus populi-glohuli Fitch. 
Pemphigus populi-ramulorum Riley. 
Pemphigus populi-transversus Riley. 
Pemphigus populi-venae Fitch. 
Pterocomma Mcolor Oestlund. 
Schizoneura populi Gillette. 
Stagona vesicalis Rudow. 
ThecaMus patchii Gillette. 
ThecaMus populicaulis Fitch. 
ThecaMus populi-monilis Riley. 
Populus candicans=P. alba. 
Asiphum pseudohyrsa Walsh. 
Chaitophorus candicans Thomas. 
Pterocomma salicis Linnaeus. 
Populus canadensis. 
Chaitophorus leticomelas Koch. 
Pemphigus canadensis Del Guercio. 
