It has sometimes been erroneously stated that "Come and Be My Butterfly" was replaced by "The Polka Contest" (performed by Ambrose, Ermengarde, Irene, Cornelius, Barnaby and the ensemble). shortly after the opening. In Before the Parade Passes By, a biography of Gower Champion by John Anthony Gilvey, it is stated (on page 152) that the change was made when Ginger Rogers took over as Dolly on August 9, 1965. This also seems to be incorrect as a playbill from July 1965 does not list "Come and Be My Butterfly" but does list "The Polka Contest." A playbill from June 1965 does list "Come and Be My Butterfly." So the change seems to have been made sometime between June and July. This alighs with something else that has occasionally been stated — that the change was first tried in the first national company, which opened in April 1965, and then was put into the Broadway production. Some state that the change was first made in the Australian production, which opened in March 1965, and it was then used in the first national company. This may be true but we have not been able to definitively confirm it.
The playbills we have seen suggest that the change was made in the Broadway production when Charles Nelson Reilly and Eileen Brennan left the show and were replaced by Lawrence Holofcener and Patte Finley in mid-July 1965. Carol Channing was still in the show at the time. Playbills from July 1965, with Channing as Dolly (along with Holofcener and Finley), list "The Polka Contest" and do not list "Come and Be My Butterfly."