Mating problems

[TheGreenMan]

My friend wanted me to post a question on these forums as he is having difficulty getting his Ctenomorpha (margin winged) to mate and his Golaiths also. He has mature males and females but no sign of mating. any idea what could be causing this to happen? I have never had problems with any of my species so i'm baffled as to what might be causing them to not show interest in each other. any input is apprecaited.

[Daniel Ballmer]

I often don't see matings. There are species and individuals which mate only at night.