Pemphigus borealis Tullgren, 1909
on Populus, primary host plant
gall
red or green globular purse gall at the base of a still green shoot. The gall is so strongly curved that the broad, apical opening almost touches the base. The gall is maximally 2.5 cm large, and often occurs in fused groups of 4-6.
host plants
Salicaceae, monophagous
Populus balsamifera, x berolinensis, laurifolia, nigra, suaveolens.
on Bidens, secondary host plant
gall
aphids at the roots.
host plants
Asteraceae, monophagous
Bidens cernuus, tripartitus.
references
Bellmann (2012a), Blackman & Eastop (2014), Buhr (1965a), Dauphin & Aniotsbehere (1997a), Heie (1980a), Kollár (2011a), Lampel & Meier (2003a), Ludwig (1974a), Osiadacz & Halaj (2014a), Osiadacz & Wojciechowski (2008a), Redfern & Shirley (2011a), Tomasi (2014a), Urban (2004a).