My name is Michael and I work for a science and nature film production company in Bristol, England, called Parthenon Entertainment. We are currently researching the possibility to film a sequence involving Roridula for a nature documentary on carnivorous plants. We are hopeful to source the species without travelling to S. Africa (where they are native), so that we can film them in a studio.
As you may know, both Roridula species are mutually associated with a hemipteran species. For example R. dentata attains a significant proportion of its nitrogen by consuming the faeces of the bug, Pameridea marlothi, whilst the bug feeds on any prey captured by the plant. But even more fascinating, it appears that R. dentata is also associated with a species of spider (Synaema marlothi Dahl., Thomsidae) that appears to predate upon the resident hemipteran. See www.jstor.org/stable/4223351 for more information.
We are hopeful to film the interaction of a Roridula species with a species of Pameridea - defeacation by bugs on plant/plants eating captured prey - and if at all possible get hold of the three species above that take part in the R. dentata, P. marlothi and S. marlothi interaction.
We would love to hear from anyone who thinks they could help us get the species to film this behaviour. Additionally, if you know of any other amazing animal/carnivorous plant interactions then we would love to hear about them.
Marcel is right, quite a few European growers have both Roridula and Pameridea bugs, I had them myself for quite a few years. I currently grow Roridula gorgonias but do not have Pameridea any more after an unfortunate insecticide incident.... pameridea feeding by gardenofeden67, on Flickr
you may also want to try the german forum at forum.carnivoren.org. I am not really sure, but i think some germans are still having plants with bugs.
I have seen myself both species in habitat in 2009 and could take some pictures of the bugs too. If that would be a help, just let me know.
I think it wouldn't be a good idea to travel to South Africa just to film these plants. Both species have a very restricted distribution and are almost unfindable if you do not exactly know where to look for them.
Btw, not only Roridula do have assin bugs, some Drosera have them too.