Nice. P.heraclei is one of those species that does turn up quite regularly for me but it is usually uncommon. Another good reason to always take specimens and really key them through even though it looks like "just another P.vulgaris"
Well, in the field one can easily spot 'possible heraclei' by the small reddish spots at sides of tergite3. But these didn't show in the pictures above, which explained the first guess of Ph. vulgaris.