Lycaenidae: Polyommatinae

07162 Chapman's Blue Polyommatus thersites, (Cantener, 1835)

BF -- (ABH61.000)

Slavyanka Mtn. foothills, 1st July 2008, male clearly showing androconial patch.
Slavyanka Mtn. foothills, 1st July 2008, male clearly showing androconial patch.
 Photo © Nick Greatorex-Davies
Slavyanka Mtn. foothills, 1st July 2008, male clearly showing androconial patch.
 Photo © Nick Greatorex-Davies
 2010-2016
 2017
 2018
 2019
Slavyanka Mtn. foothills, 1st July 2008, male.
Slavyanka Mtn. foothills, 1st July 2008, male.
 Photo © Nick Greatorex-Davies
Patnikovo, Eastern Rhodopis, 18th June 2014, male.
Patnikovo, Eastern Rhodopis, 18th June 2014, male.
 Photo © Nick Greatorex-Davies
Patnikovo, Eastern Rhodopis, 18th June 2014, male.
Patnikovo, Eastern Rhodopis, 18th June 2014, male.
 Photo © Nick Greatorex-Davies
Hvoyna, Western Rhodopi Mtns., 11th June 2011, male.
Hvoyna, Western Rhodopi Mtns., 11th June 2011, male.
 Photo © Nick Greatorex-Davies
Petrovo, SW Bulgaria, 1st July 2008, male.
Petrovo, SW Bulgaria, 1st July 2008, male.
 Photo © Nick Greatorex-Davies
Arda valley, Eastern Rhodopis, 16th June 2014. Male.
Arda valley, Eastern Rhodopis, 16th June 2014. Male.
 Photo © Nick Greatorex-Davies
Arda valley, Eastern Rhodopis, 16th June 2014. Male.
Arda valley, Eastern Rhodopis, 16th June 2014. Male.
 Photo © Nick Greatorex-Davies
S. of Koprivlen, SW Bulgaria, 5th May 2014. Male.
S. of Koprivlen, SW Bulgaria, 5th May 2014. Male.
 Photo © Nick Greatorex-Davies
S of Koprivlen, SW Bulgaria. 11th May 2015. Male.
S of Koprivlen, SW Bulgaria. 11th May 2015. Male.
 Photo © Nick Greatorex-Davies
Chetertsi, (Kyustendil Province), W Bulgaria, 14th June 2016. Male.
Chetertsi, (Kyustendil Province), W Bulgaria, 14th June 2016. Male.
 Photo © Nick Greatorex-Davies
Arda valley, Eastern Rhodopi Mtns., 13th June 2013. Male.
Arda valley, Eastern Rhodopi Mtns., 13th June 2013. Male.
 Photo © Nick Greatorex-Davies
S. of Koprivlen, SW Bulgaria, 5th May 2014. Female.
S. of Koprivlen, SW Bulgaria, 5th May 2014. Female.
 Photo © Nick Greatorex-Davies
S of Koprivlen, SW Bulgaria. 11th May 2014. Female.
S of Koprivlen, SW Bulgaria. 11th May 2014. Female.
 Photo © Nick Greatorex-Davies
S of Koprivlen, SW Bulgaria. 11th May 2014. Female.
S of Koprivlen, SW Bulgaria. 11th May 2014. Female.
 Photo © Nick Greatorex-Davies
Chetertsi, Kyustedil Province, W Bulgaria, 14th June 2016.
Chetertsi, Kyustedil Province, W Bulgaria, 14th June 2016.
 Photo © Nick Greatorex-Davies
S of Koprivlen, SW Bulgaria. 11th May 2015. Male.
S of Koprivlen, SW Bulgaria. 11th May 2015. Male.
 Photo © Nick Greatorex-Davies
S of Koprivlen, SW Bulgaria. 11th May 2015. Male.
S of Koprivlen, SW Bulgaria. 11th May 2015. Male.
 Photo © Nick Greatorex-Davies
S of Koprivlen, SW Bulgaria. 11th May 2015. Female.
S of Koprivlen, SW Bulgaria. 11th May 2015. Female.
 Photo © Nick Greatorex-Davies
S of Koprivlen, SW Bulgaria. 11th May 2015. Male.
S of Koprivlen, SW Bulgaria. 11th May 2015. Male.
 Photo © Nick Greatorex-Davies


General Information

Widespread and common where foodplant is abundant

 

Easily confused with the Common Blue (Polyommatus icarus). In the male the presence of the patch of hairy androconial cells in the basal 2/5th up the upper forewing is diagnostic, but this can only be seen if the wings are open and it can be hard to see unless the light and angle of view is right.

 

The absence of the basal spot on the underside of the forewing is an indication that the specimen might be thersites, but is not diagnostic, as often Common Blues are also lacking this basal spot (form icarinus), which is much more frequent in eastern Europe than in the UK. There is often a difference in the ground colour of the underside of the wings in males, which tend to have a pale milk-chocolate ground colour contrasting with the pale grey of the underside of the forewings. However this is a subtle difference, but with experience I have found it possible to pick out thersities from icarus when they are puddling together on damp mud.



Habitat

Dry grassland often in rocky or bushy places.

 

Foodplant: Species of sanfoin (Onobrychis spp.)

Regional Information

Recorded in 38 (2%) of the 1900 10km squares of Bulgaria.

Last recorded in June 2019

Recorded date range (Adult): 05 May to 08 August

Similar Species
Dobarsko, Rila Mtns., 10th July 2008, male.
Dobarsko, Rila Mtns., 10th July 2008, male.
 Photo © Nick Greatorex-Davies
Common Blue Polyommatus icarus