Pieris pupae

Pieris pupae

Observation - Pieris pupae - UK and Ireland. Description: Three white butterfly pupae attached, by silk girdles, to three different tree trunks in close proxi

Three white butterfly pupae attached, by silk girdles, to three different tree trunks in close proximity, at about waist height. Two were light brown, but one almost white, with darker markings. The nearest available crucifers from which the caterpillars could have walked to their respective tree trunks would probably have been Garlic Mustard or perhaps Hedge Mustard or Nipplewort - about three metres away is the North Downs Way, which follows the wood edge, separating it from pasture, with the usual range of common wayside plants.
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I don't know how to separate the various whites in their pupal stage but I wonder whether the habitat might point more to Green-veined. All three species pupate through winter, of course.