when to harvest drosera seeds

[sooxiwei]

hi to all again, I'm having my drosera burmanii and drosera capilaris flowering lately, according to some, they said have to wait till the Shell of the Seed to be dried up before harvesting, but my burmanii seed's shell have not been dried up but have spilled quite a lot of black and tiny small particles around...so would like to ask when to cut off those seeds shell, tq