Does anyone have any experience with pairing Catocala?
I reared a good number of C. retecta this year. I had more than I needed for pins so I put 8 males and 5 females into a netting cage 17" high with a 13" diameter. I feed them every evening with sugar solution on cotton wool pads. They've been in there for more than 3 weeks now and still seem healthy and strong, they fly quite a lot - even during daylight.
My question is: what sort of time should they pair and how long should the pairing last? I've been checking the cage about midnight before I go to bed, and again when I wake up but I've seen no pairings. I've seen the occasional couple in the morning very close to each other as if they'd just separated but they could equally have just settled down this way. If I do get a paired female I'd like to remove it for laying but currently I've no way of knowing whether they've paired.
I assume that by "host" you mean the host plant. I don't think that Catocala would need the foodplant present to pair, they certainly don't need it to lay. But it certainly wouldn't do any harm to try so I'll give it a go.