No, it's a common misconception about nature and evolution that I genuinely dislike having to tell people because of how often it comes up.

And no, I didn't know what you meant. Like I guess your phrasing leaves room for your clarification as an interpretation, but I definitely don't think of a complete lack of feeling when you say "cause any feeling but pleasure".

Lastly, why would they not feel pain from it? There's no particular reason they would feel pain either, but neither situation confers any obvious evolutionary advantage - indeed, it only comes up once they reproduce, so if there is a pain response it's not advantageous or disadvantageous until they've already passed their genes on.
We've just barely started grappling with the idea of that maybe plants feel pain and have some form of consciousness, only having some weird data that we're still trying to make full sense of - you have no basis by which to assert that they're capable of feeling pleasure, never mind the specific things they'd enjoy.