Seq # 460140010

Cyaniris semiargus (Rottemburg, 1775) Species

Last modified: Sept. 14, 2023, 1:36 p.m.

In Flanders the species is critically endangered. A local species occurring in the south of Belgium where it is vulnerable.


Family: Lycaenidae > Subfamily: Polyommatinae > Tribus: Polyommatini > Genus: Cyaniris > Species: Cyaniris semiargus
Vernacular names
Klaverblauwtje (NL), Mazarine Blue (EN), Demi-Argus (FR), Rotklee-Bläuling (DE)
Cyaniris acis (Denis & Schiffermüller, 1775), nec (Drury, 1773)
First mention in Belgium
De Sélys-Longchamps E. 1837. Catalogue des Lépidoptères ou Papillons de la Belgique, précédé du tableau des Libellulines de ce pays. — — : 1–29. On page 17 (as Polyommatus Acis). view page




Museum specimens

No pictures yet!

Specimens in nature

Flight periods

The adults fly in two generations a year: from mid May till the end of June, and from mid July till end of August. In favourable years a third generation occurs from the beginning of September till early October.

Observed on

Host plant (species):
Trifolium pratense

The larva lives on Trifolium pratense and is attended by ants of the genus Lasius.

No pictures yet!