Steven Cheshire's British Butterflies
British Butterflies: Species: Species Account - The Mazarine Blue:
Mazarine Blue
Polyommatus semiargus (Rottemburg, 1775)

Mazarine Blue egg.
  Mazarine Blue caterpillar.
  Mazarine Blue chrysalis
Mazarine Blue
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Insecta: Lepidoptera : Family Lycaenidae: Subfamily Lycaeninae : Genus Polyommatus: Species semiargus:
The Mazarine Blue became extinct in Britain in 1904 although it remains widespread on mainland Europe but is declining in many European countries... primarily due to habitat loss. The adult butterflies are very similar in size to the Common Blue but the blue colouration is very much darker. The underwings of the Mazarine Blue also lack the distinctive orange spots which are present on the Common Blue.
The Mazarine Blue occurs in a wide range of flower habitats where the larval foodplant occurs.
The reasons for the decline and ultimate extinction of the Mazarine Blue in Britain is unknown. There is also very little infomation about its original distribution in the UK.
Where to see the Mazarine Blue in the British Isles
Other notes
Lifecycle chart
Flight chart
The lifecycle and flight charts should be regarded as approximate guides to the Mazarine Blue in Britain. Specific lifecycle states, adult emergence and peak flight times vary from year to year due to variations in weather conditions.
IUCN category status 2010 5   IUCN category status 2007 34
Regionally Extinct Regionally Extinct

5Fox, R., Warren, M., Brereton, T. M., Roy, D. B. & Robinson, A.
(2010) A new Red List of British Butterflies. Insect Conservation and Diversity.
Regionally Extinct Regionally Extinct

3Fox, R., Warren, M & Brereton, T.
(2007) New Red List of British Butterflies. Butterfly Conservation, Wareham.

4More information about IUCN categories.
UK status
Larval foodplants
The primary larval foodplant of the Mazarine Blue is Red Clover (Trifolium pratense).
Butterflies of Britain ID Chart
Your personal guide to British Butterflies. This 8-panel laminated chart is designed for speedy butterfly identification in the field. Ideal for anyone interested in identifying butterflies, perfect for children and adults and ideal for outdoor use, laminated, shower-proof and robust. Get your copy today.
Butterflies of Britain (Laminated ID Chart).
Online store
Visit our online store for many more butterfly related books and gifts.
Population trends 1
UK Population trend 1995-2004 not applicable
UK Population trend 1976-2004 not applicable

1Fox, R., Asher. J., Brereton. T., Roy, D & Warren, M. (2006) The State of Butterflies in Britain & Ireland, Pices, Oxford.
UK BAP status 2
UK BAP status not applicable (link)

2For information about the UK Biodiversity Action Plan, visit the JNCC web site

National Biodiversity Network Gateway
National Biodiversity Network Gateway Distribution Map

Areas in and indicate a contraction in distribution of the Mazarine Blue except in Ireland where data is only available up until 1999.

* Records shown in outside the natural distribution may be the result of illegal or accidental releases by breeders or, depending upon the species, migrant individuals from mainland Europe.

Key to map*
= 2000 to 2010 inclusive (current distribution)
= records from 1950 to 1999 inclusive
= records from 1900 to 1949 inclusive
Records prior to 1st January 1900 are not shown.

The NBN Gateway records are shown on the map right. (See terms and conditions).

More data is available on the Mazarine Blue on the NBN Gateway web site.
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For full details of books and reports mentioned on this web site, view the references page.

Find out more online*
Mazarine Blue can be found on Peter Eeles excellent UK Butterflies web site.
Mazarine Blue can be found on Matt Rowlings excellent European Butterflies web site.

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Photographs of the Mazarine Blue
Image ID BB829 - Mazarine Blue - © Steven Cheshire
Mazarine Blue unknown (imago)
BB829 ©
Image ID BB754 - Mazarine Blue - © Steven Cheshire
Mazarine Blue unknown (imago)
BB754 ©
Image ID BB753 - Mazarine Blue - © Steven Cheshire
Mazarine Blue male (imago)
BB753 ©
Image ID BB752 - Mazarine Blue - © Steven Cheshire
Mazarine Blue male (imago)
BB752 ©
Image ID BB751 - Mazarine Blue - © Steven Cheshire
Mazarine Blue male (imago)
BB751 ©
Image ID BB750 - Mazarine Blue - © Steven Cheshire
Mazarine Blue male (imago)
BB750 ©
Image ID BB749 - Mazarine Blue - © Steven Cheshire
Mazarine Blue male (imago)
BB749 ©
Image ID BB748 - Mazarine Blue - © Steven Cheshire
Mazarine Blue male (imago)
BB748 ©
Image ID BB747 - Mazarine Blue - © Steven Cheshire
Mazarine Blue male (imago)
BB747 ©
Image ID BB746 - Mazarine Blue - © Steven Cheshire
Mazarine Blue male (imago)
BB746 ©
There are 12 photographs of the Mazarine Blue in our stock photo library.
View more photographs of the Mazarine Blue as a thumbnail gallery or as a slideshow.