A male Pieris brassica or Gonepteryx rhamni had also been observed "leaf tasting" in search of females that had not been mated.
When landing (and looking to lay), a female touched briefly an unsuitable leaf before flying off.
I thought that I might of had some evidence, on at least one occasion, that a female Pieris brassica, when I looked at her in slow motion, used her proboscis to help taste a leaf briefly, before flying away, to find a better place to lay her eggs.
As one knows, some butterflies, when disturbed from nectaring, fly off before, retracting their proboscis.
![Shocked :shock:](./images/smilies/icon_eek.gif)
Here was a video link:
https://youtu.be/1bi_S9Suvzg
Kind Regards