Hi Steve and Guus. No, you don't need CITES for orchid seeds, but there is some confusion about whole seed pods.
"The current annotation for Appendix-II Orchidaceae, Annotation #1, specifies that seeds are exempt from CITES controls, but it does not exempt seedpods (fruits)."
https://cites.org/eng/node/84280Invitro cultures/seedlings are also OK.
"Therefore it would be better to exempt all flasked seedlings of orchids from the requirements of the Convention.
In the case of species listed in Appendix II or III, and hybrids thereof, this exemption was made possible with the
adoption of an amendment to Appendix II at the fifth meeting of the Conference of the Parties and of Resolution Conf.
6.18. T"
https://cites.org/sites/default/files/eng/cop/08/doc/E-27-29-31.pdfFortunately, almost all orchid species are Appendix II species except 7 specific species and the genera Phragmipediun and Paphiopedilum (Appendix I).
https://cites.org/eng/app/appendices.phpAnders