The unupped ability is very amusing. Though I wish you could fit that the chance is based on HP somehow...
Hmm... the upped version ability will lose its swarm synergy. I actually think you should keep the same ability for both. The unupped version is unique and distinct from other poison spreaders, and it synnergies well with the swarm ability.
These guys seem very tough for wasps. I kinda wish they were a little smaller. Having a lower cost could help promote use alongside Pharaoh to promote greater utility of swarm based strategies.
As it is right now, trying to add it to a pharaoh deck would require a trio or bow... Given the inherent instability of trios, the relatively high cost will be prohibitive. That basically relegates it to air - life mitosis duos or rainbow decks.