Polyommatus thersites

(Cantener, 1835)

Chapman's Blue

Description:
Chapman's Blue looks very like the Common Blue (P. icarus). However, the two black spots in the cell on the underside of the forewing are absent. It occurs in warm, dry places, such as calcareous and poor grasslands, fields of sainfoin, and abandoned agricultural land.
Eggs are laid on Sainfoin (Onobrychis viciifolia), and in Greece also on Cockscomb Sainfoin (O. caput-galli). The caterpillars feed on soft parts of the leaflets, leaving the veins. The small caterpillars go into hibernation, and in those parts of the range with hot climates, the egg goes into aestivation. The caterpillars are attended by ants of the genera Lasius, Formica, and Tapinoma, and hide themselves in the litter layer and pupate.
The Chapman's Blue usually has two generations a year, but in the south of the range also three.

Habitat:
Dry siliceous grasslands
Dry calcareous grasslands
Mesophile grasslands

Similar species:
Polyommatus dorylas
Polyommatus icarus
Polyommatus escheri

%LABEL% (%SOURCE%)