Some wild creatures just don't do well in captivity. Is it really an invasive species? If so, don't release it back into the wild, but if it's not invasive, it would be best to put it back where you found it.
Hi, ciwi92: Please translate your posts into English, as this is an English-speaking Forum. I have used Google translate for you this first time, but after this your German posts will be deleted.
From Google translate:
Hello I have a question I have a Conrau`s pygmy gecko lygodactylus I...