Isolating new beetle from others

[Darcie]

Yesterday, I got a Cryptoglossa variolosa (black death feigning beetle). I have 3 other beetles, 2 smooth death feigning beetles and 1 blue. I put the new black one in a temporary enclosure just to be safe.

How long should I leave it in the temporary enclosure before introducing it to the tank with my other 3 beetles? How do I know if it's sick? It's been walking around, sleeping, and it ate some washed organic grapes.

It seems to move somewhat slowly, but otherwise seems fine. No leg twitching, can flip itself back up if it falls on its back (it had slipped on some cardboard tubes in the enclosure). Any insight?

 

[Elytra and Antenna]

I've never heard of quarantining darkling beetles like fish. If you do I would guess 30 days should be enough.

 

[Salmonsaladsandwich]

I'm not sure how you would recognize a contagious disease in a darkling beetle nor have I ever heard of that being an issue. I'm not saying it's not a legitimate concern, but I'm not sure what quarantining would achieve since I doubt a diseased beetles' external appearance or behavior would change noticeably unless it's near death which I imagine could take a while considering the toughness and longevity of these sorts of beetles.