Material. 2 al., No. 10194, ChD, 1 km north of Pevek, N 69 ° 42 ', E 170 ° 21 ', 4.vii. 2011, dry mountain terrace with forb-lichen-dryad vegetation, sweeping; 1 al., No. 10195, ChD, 1 km north of Pevek, N 69 ° 42 ', E 170 ° 21 ', 7.vii. 2011, spotty lichen-semishrub (dwarf willows, dryad)-moss tundra on foothill of the western exposition, sweeping; 1 al., No. 10196, in the same locality as No. 10194, 7.vii. 2011, sweeping; 1 al., No. 10262, SSWBer, 20.vii. 2012, in yellow trap.
Distribution outside Chukotka AO. Europe, north Africa, west and Central Asia, India, Australia, North and South America.
Comments. In the vicinity of Pevek this species was found in the single locality with severe (dry and windy) conditions, where it inhabited cooler sites in foothills and mountain terraces.
Specimens of B. rumexicolens from Chukotka have long setae on dorsal side of abdomen (longest seta on abdominal tergite III 18–30 Μm) and large marginal and spinal tubercles; usually setae on abdominal tergite III of specimens of this species are short (5–8 Μm according to Heie, 1992) and marginal and spinal tubercles are absent or very small. However the length of setae in this species can vary greatly between populations (Alexey Andreev, personal comm.), and intraspecific variability of the number and dimension of tubercles is also common in aphids of the subtribe Anuraphidina. Further work is needed to assess the significance of this variation within and between populations.