Food
Poplar (Populus) or willow (Salix), depending on species.
Remarks
The following host and location clues, from
(1), may help to narrow down possibilities. Descriptions of the aphids can be found by following that link.
On poplar:
Chaitophorus leucomelas Koch - On young shoots of Populus spp. in spring, and later under leaves, in leaves stuck together by moth larvae, or leaf galls vacated by other insects; always ant-attended
Chaitophorus neglectus Hottes & Frison - On upper and undersides of leaves, or in leaves folded and stuck together by other insects, of aspens (Populus tremuloides, P. grandidentata) and of P. deltoides. Widely distributed in North America.
Chaitophorus nodulosus Richards - On Populus sp. in Utah
Chaitophorus nudus Richards - In rather small colonies girdling trunk of saplings of Populus tremuloides; recorded from Manitoba, Ontario, Colorado, Pennsylvania
Chaitophorus populicola Thomas - In often dense colonies on young shoots and developing leaves of numerous Populus spp. throughout North America
Chaitophorus populifolii Essig - On leaves of Populus spp., especially angustifolia and balsamifera, sometimes on deltoides or tremuloides; widespread in USA, Canada, Mexico
Chaitophorus stevensis Sanborn - Ant-attended, on leaves of Populus spp., apparently restricting its feeding to aspens and cottonwoods; records from balsam poplars are probably misidentified populifolii. It is frequently associated with leaf-fold galls of Thecabius populiconduplifolius. Widely distributed in North America.
On willow:
Chaitophorus crucis (Essig) - Found in dense colonies on undersides of leaves of Salix macrostachyae in California
Chaitophorus eoessigi Hille Ris Lambers - Mostly on the apical parts of leaves, on both upper and undersides, of unidentified Salix sp(p). in southern California and Mexico
Chaitophorus longipes Tissot - on young tender stems of Salix caroliniana in eastern USA
Chaitophorus longiunguis Robinson - On an unidentified Salix sp. in Utah
Chaitophorus macgillivrayae Richards - On an unidentified Salix sp. in eastern Canada (Quebec, New Brunswick)
Chaitophorus macrostachyae (Essig) - Usually found on roots and parts of trunk of Salix spp. at or below ground level, but colonies may also form at tips of twigs (Essig 1912). In western North America.
Chaitophorus minutus (Tissot) - In dense colonies on undersides of leaves of Salix caroliniana in eastern USA (Florida, Louisiana, South Carolina).
Chaitophorus monelli (Essig) - Found on tender shoots and suckers of Salix lasiolepis and S. laevigata in California
Chaitophorus nigrae Oestlund - In sometimes large colonies on leaves and petioles of new growth of various Salix spp. Widely distributed in North America.
Chaitophorus nigricentrus Richards - Found only on second-year growth of (unidentified) Salix sp(p); recorded from Ontario and Pennsylvania
Chaitophorus pallipes Richards - On young growth of Salix discolor and possibly other Salix spp.; Ontario, British Columbia, Prince Edward Island, North Carolina
Chaitophorus pusillus Hottes & Frison - On upper and undersides of leaves of Salix amygdaloides in Illinois; also recorded from S. discolor and unidentified Salix spp. in other parts of USA and Canada.
Chaitophorus pustulatus Hille Ris Lambers - On leaves of Salix sp. in Utah, Colorado, Wyoming, British Columbia, Idaho, Oregon.
Chaitophorus saliciniger (Knowlton) - On bark of twigs of unidentified Salix sp(p). in Colorado and Utah
Chaitophorus utahensis (Knowlton) - On bark of twigs and extending onto leaf petioles, or on trunk 15-20 cm above ground level, of unidentified Salix sp(p)., in western USA
Chaitophorus viminalis Monell - On leaves and young growth of various narrow-leafed Salix spp. throughout North America
Chaitophorus viminicola Hille Ris Lambers - On Salix nigra and unidentified Salix sp(p). in eastern USA and Canada (Ontario)
