Polyommatus thersites

English name:
Chapman’s Blue
Full scientific name:
Polyommatus thersites (Cantener, 1835)
Croatian name:
Grahorkin plavac

Red Book Category in EU: LC

Red Book Category in Croatia: NT

Wings span: 25-31 mm

Polyommatus thersites, male, Medvednica, 0522L8621
Polyommatus thersites, male, Medvednica, 0522L8621
Polyommatus thersites, male, Medvednica, 0522L8621
Polyommatus thersites, male, Medvednica, 0522L8621
Polyommatus thersites, female, Medvednica, 0522L8271
Polyommatus thersites, female, Medvednica, 0522L8271
Polyommatus thersites, female, Medvednica, 0522L8271
Polyommatus thersites, female, Medvednica, 0522L8271

Flight Period and Life Cycle

Flight period of Polyommatus thersites in Croatia
Flight period of Polyommatus thersites in Croatia

2 broods per year. Overwinters as caterpillar.

Distribution in Croatia

Distribution of Polyommatus thersites in Croatia
Distribution of Polyommatus thersites in Croatia

Common in the coastal area. Check the included map.

External Morphology Characteristics

The upper side of wings is blue in males and brown in females. Males have blue gradual darkening in discal and postdiscal zones on the upper side of the forewing. This is andriconal zone. In females, the series of dark and orange spots are more prominent on both wings. The cell spot is missing. Similar to Polyommatus icarus form icarinus and Polyommatus escheri. The comparison is below:

Polyommatus escheri, Polyommatus icarus form icarinus and Polyommatus thersites ID characteristics of ventral view
Polyommatus escheri, Polyommatus icarus form icarinus and Polyommatus thersites ID characteristics of lateral view, wings closed

(1) Orange spot in S7 is more prominent in Polyommatus thersites and very weak in Polyommatus escheri.
(2) In Polyommatus thersites in zones from S2 to S4, the orange spots barely touch margin black spot, and touch is absent in S5 and S6. In Polyommatus icarus form icarinus there is a noticeable stronger touch in S2 and S3. The touch weakens in S4 and S5 and there is no touch in the S6. In Polyommatus escheri, the touch is weak on S4 and almost absent on S6.
(3) The black elongated spot in the discal zone is weakly expressed in Polyommatus thersites. It is a bit more prominent in Polyommatus icarus form icarinus. In Polyommatus escheri, it is clearly marked and has sharp edges.
(4) Black spots in zones S5, S6 and S7 are placed on a slightly curved imaginary line. The imaginary line is marked in pink color. In Polyommatus thersites, that imaginary line is a little more rounded, i.e. a black discal spot in zone S6 is closer to the orange spot in zone S7.

Behavior

Imago feeds with nectar of various flowers.

Caterpillar Host Plants

Family legume (Fabaceae) like Onobrychis viciifolia.

Habitat

Flower meadows reach with legume. Elevations: 100-1100m.

Gallery

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