This butterfly gets its common name from the long thin tail on the trailing edge of each hindwing. The tails are black with white tips, but unfortunately the butterfly pictured above has suffered damage to its hindwings and so the tails are not evident. As with so many other butterflies, the male (wingspan 24-32mm) and often slightly smaller than the females (wingspan 24-34mm). The pale bar on the intricately patterned underwing helps distinguish it from the very similar Lang's Short-tailed Blue, Leptotes pirithous.
The specimens shown here were photographed in the Algarve region of Portugal. (Pictures: Rob Petley-Jones)
In Britain the Long-tailed Blue occurs along the south coast of England and the Channel Islands very occasionally as a migrant, but it is a very rare sight in Britain because the winters are generally too cold for its survival. On mainland Europe this is a butterfly of southern countries. Elsewhere this species can be found in northern Africa and in parts of Asia and Australia.
The larval foodplants used by the Long-tailed Blue include various peas (Fabaceae), and it is considered a pest of Broad Bean and Pea crops in agricultural areas where it feeds first on the leaves and then on the contents of the seedpods.
In the Algarve and in southern Spain these butterflies can be found throughout most of the year; the specimens shown here were seen in May.
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