The Ilex Hairstreak (Satyrium ilicis) strongly resembles the False Ilex Hairstreak (Satyrium esculi) and also the Sloe Hairstreak (Satyrium acaciae) but this latter does not occur in Spain and Portugal.
The False Ilex Hairstreak is principally an Iberian species and can be confused only in Spain and Portugal (and sometimes in southern France) with the Ilex Hairstreak which occurs in southern and central Europe.
However, there are some small differences between the Ilex Hairstreak and the False Ilex Hairstreak.
The Ilex Hairstreak is darker chocolate brown and its orange spots are somewhat paler in color and more clearly marked by black edging.
The orange spots in the False Ilex Hairstreak are finely edged black only on the inside; on the outside this is residual or absent.
In the Ilex Hairstreak, the marginal white line seems to be stronger, while for the False Ilex Hairstreak it is weaker and may just reach as high as the tail.

In the garden of B&B Granja da Cabrita, Coimbra, Portugal, 11 June 2023