If you are still looking for Dr. Gustave (note spelling) Dahms of the St. Louis area, a daughter died in the Albany, NY area in 2009 -- Patricia H. Shepherd. Obituary mentioning her parents is available on-line. Her mother was a nurse; I have seen the name spelled as Celina and Selina. You can find names and cities of other descendants in the obituary.
I became interested in Dr. Dahms as he did illustrations for some scientific studies of wasp behavior and at least once his observations were published as part of a larger publication.