Common Blue (<i>Polyommatus icarus</i>)

The Common Blue is a very common butterfly. It looks rather like Chapman’s Blue (P. thersites), but the two black spots on the underside of its front wings distinguish it in most specimens. It can be found on most types of grassy vegetation, ranging from quite dry, poor grassland to moderately damp meadows. The female lays her eggs on a variety of leguminous plants, including Common Birdsfoot–trefoil (Lotus corniculatus). The caterpillars feed on the leaves. They are attended by ants of the genera Lasius, Formica, Myrmica, Tapinoma, and Plagiolepis. When half-grown, the caterpillars may hibernate in the litter layer. In hot climates, aestivation possibly also takes place, in the egg or larval stage. The caterpillars pupate in the litter layer. Depending on the geographical position and altitude of the breeding ground, the Common Blue has one to three (or even more) generations a year.

Family	Lycaenidae
Subfamily	Polyommatinae
Genus	Polyommatus
Species	icarus
Authority	(Rottemburg, 1775)
English Name	Common Blue

European Red List 2010	Least Concern (LC)
EU 27 Red List 2010	Least Concern (LC)
European Red List 2025	Least Concern (LC)
EU 27 Red List 2025	Least Concern (LC)
Habitats Directive
Bern Convention
CITES

#	Order	Family	Genus	Species	Vernacular Name
1	Fabales	Fabaceae	Astragalus	glycyphyllos	Wild Liquorice
2	Fabales	Fabaceae	Astragalus	monspessulanus
3	Fabales	Fabaceae	Astragalus	sirinicus
4	Fabales	Fabaceae	Astragalus	thracicus
5	Fabales	Fabaceae	Coronilla	varia
6	Fabales	Fabaceae	Cytisus	scoparius	Broom
7	Fabales	Fabaceae	Genista	hispanica	Spanish Gorse
8	Fabales	Fabaceae	Genista	pilosa	Hairy Greenweed
9	Fabales	Fabaceae	Hippocrepis	comosa	Horseshoe Vetch
10	Fabales	Fabaceae	Lathyrus	oleraceus	Garden Pea
11	Fabales	Fabaceae	Lotus	angustissimus	Slender Bird's-foot-trefoil
12	Fabales	Fabaceae	Lotus	corniculatus	Common Bird's-foot-trefoil
13	Fabales	Fabaceae	Lotus	corniculatus ssp. corniculatus
14	Fabales	Fabaceae	Lotus	corniculatus ssp. delortii
15	Fabales	Fabaceae	Lotus	dorycnium
16	Fabales	Fabaceae	Lotus	glareosus
17	Fabales	Fabaceae	Lotus	hirsutus	Hairy Canary-clover
18	Fabales	Fabaceae	Lotus	ornithopodioides
19	Fabales	Fabaceae	Lotus	pedunculatus	Greater Bird's-foot-trefoil
20	Fabales	Fabaceae	Lotus	pedunculatus ssp. pedunculatus
21	Fabales	Fabaceae	Medicago		Medicks
22	Fabales	Fabaceae	Medicago	x varia	Medicks
23	Fabales	Fabaceae	Medicago	disciformis
24	Fabales	Fabaceae	Medicago	falcata
25	Fabales	Fabaceae	Medicago	littoralis	Shore Medick
26	Fabales	Fabaceae	Medicago	lupulina	Black Medick
27	Fabales	Fabaceae	Medicago	minima	Bur Medick
28	Fabales	Fabaceae	Medicago	polymorpha	Toothed Medick
29	Fabales	Fabaceae	Medicago	sativa	Lucerne (see ssp.)
30	Fabales	Fabaceae	Medicago	truncatula	Strong-spined Medick
31	Fabales	Fabaceae	Melilotus		Melilots
32	Fabales	Fabaceae	Melilotus	albus	White Melilot
33	Fabales	Fabaceae	Melilotus	indicus	Small Melilot
34	Fabales	Fabaceae	Melilotus	officinalis	Ribbed Melilot
35	Fabales	Fabaceae	Onobrychis	caput-galli
36	Fabales	Fabaceae	Onobrychis	supina
37	Fabales	Fabaceae	Onobrychis	viciifolia	Sainfoin
38	Fabales	Fabaceae	Ononis	arvensis
39	Fabales	Fabaceae	Ononis	spinosa	Spiny Restharrow
40	Fabales	Fabaceae	Ononis	spinosa ssp. procurrens
41	Fabales	Fabaceae	Ononis	spinosa ssp. spinosa
42	Fabales	Fabaceae	Ornithopus	perpusillus	Bird's-foot
43	Fabales	Fabaceae	Oxytropis	campestris	Yellow Oxytropis
44	Fabales	Fabaceae	Spartium		Spanish Broom
45	Fabales	Fabaceae	Trifolium		Clovers
46	Fabales	Fabaceae	Trifolium	arvense	Hare's-foot Clover
47	Fabales	Fabaceae	Trifolium	campestre	Hop Trefoil
48	Fabales	Fabaceae	Trifolium	dubium	Lesser Trefoil
49	Fabales	Fabaceae	Trifolium	fragiferum	Strawberry Clover
50	Fabales	Fabaceae	Trifolium	nigrescens
51	Fabales	Fabaceae	Trifolium	ochroleucon	Sulphur Clover
52	Fabales	Fabaceae	Trifolium	parnassi
53	Fabales	Fabaceae	Trifolium	pratense	Red Clover
54	Fabales	Fabaceae	Trifolium	repens	White Clover
55	Fabales	Fabaceae	Trifolium	scabrum	Rough Clover
56	Fabales	Fabaceae	Ulex	europaeus	Gorse
57	Fabales	Fabaceae	Ulex	parviflorus
58	Fabales	Fabaceae	Vicia	hirsuta

Common Blue (Polyommatus icarus)

Description

Distribution

Larval Foodplants