Common Blue

Common Blues often spend their caterpillar days guarded by ants, who eat the honeydew that the caterpillars secrete. In return, the ants ward off predators. The butterflies emerge from mid-May onward in the UK. Male Common Blues are violet-blue, and females are brown and orange.

The rich yellow flowers in the photos below, taken in the UK and Spain, are called Bird’s-Foot Trefoil. Common Blue caterpillars eat them, and these wildflowers also provide nectar for many insects.

Common Blues can be mistaken for a few other species. The butterfly below is not a Blue at all. It is a Brown Argus, which is found in the same habitats. Marked by the red circle, there is a ‘figure of eight’ – two spots side by side – on the lower wing, which distinguishes it from Common Blues. Other differences include its brown, chequered border, while Common Blues are fringed completely in white.

Sources

‘Bird’s-Foot Trefoil’ (UK: Plantlife, 2020) <https://www.plantlife.org.uk/uk/discover-wild-plants-nature/plant-fungi-species/birds-foot-trefoil&gt;

Eeles, Peter, ‘Similar Species’ (UK: UK Butterflies, 2020) <https://www.ukbutterflies.co.uk/species_similarities.php&gt;

Foley, Caroline, The Natural Garden Handbook (London: New Holland, 2009) p 58