61.019 Polyommatus (Lysandra) bellargus (Adonis Blue)
ws: 30-40mm; bivoltine May-Jun, Aug-Sep; horseshoe vetch (Hippocrepis comosa); chalk and limestone downs in S.England.
ID: Males have a bright turquoise blue upperside with a narrow black border and white fringes chequered due to a black mark overlaying the terminal portion of each vein and extending to the outer edge of the fringe. Males are similar to males of P.icarus (Common Blue), Plebeius argus (Silver-studded Blue) and both sexes of Celastrina argeolus (Holly Blue). Male P.bellargus is a brighter shade of blue than male P.icarus. P.icarus may show a black mark at the terminal portion of the veins but it does not extend more than halfway into the fringe. Both P.argus and C.argeolus have a broader black margin to the upperside of both wings. P.argus has clear white fringes. C.argeolus lacks any orange marks on the underside. Females upperside is brown with a variable amount of blue, and very similar to female P.coridon (Chalk Hill Blue). Both P.coridon and P.bellargus can be distinguished from similar species by the dark brown ground colour to the hindwing and the chequered fringes. On the hindwing upperside P.corridon and P.bellargus show a row of subterminal black spots, bordered proximally with orange. In P.corridon the black spots are bordered distally with white and in P.bellargus they are bordered distally with blue.
Page published 22/07/2014 (§1-3)