Euceraphis borealis Blackman

Euceraphis borealis Blackman in Blackman and De Boise, 2002

Material. 3 al., No. 10233, SSWBer, Betula nana exilis (Sukaczev) Hulten, 6.vii.2012, on upper and lower surface of leaves; 2 al., No. 10265, SSWBer, Betula nana exilis (Sukaczev) Hulten, 26.vii.2012, on lower surface of leaves; 3 al., No. 10271, SSWBer, Betula nana exilis (Sukaczev) Hulten, 2.viii.2012, on lower surface of leaves.

Distribution outside Chukotka AO. Finland, Canada (Quebec, Manitoba, North-west Territories), USA (Alaska).

Comments. Specimens from Chukotka differ slightly in morphology from those described by Blackman and De Boise (2002). Our specimens have a slightly shorter base of the 6th antennal segment—306–372 (320–390 in Blackman and De Boise), a greater range of the ratio of the 5th antennal segment to the base of the 6th antennal segment—2.09–2.79 (2.16–2.73 in Blackman and De Boise), a slightly lower ratio of the length of the 6th antennal segment to the length of the ultimate rostral segment—2.35–2.72 (2.38–3.05 in Blackman and De Boise), and slightly greater ratio of length of the ultimate rostral segment and the length of the 2nd segment of the hind tarsus— 0.60–0.65 (0.52–0.62 in Blackman and De Boise). However, these are minor differences and are probably the result of simple geographic variation.