Distribution Burundi, Kenya, S Sudan, Rwanda, Tanzania, Uganda, N/E Zaire (Democratic Republic of the Congo)
Type locality: Bugoye, east foot of Ruwenzori Mts., Uganda.
Photo doesn't really show a spot. I see something that looks like maybe some skin shed, or a piece of bug debris on lip. Another picture would help. Is it on the inside of mouth to?
Over 80% of trees and plants found in Jungles are toxic in varying degrees. So, I've so soften my views on what, and what not to use. Funny to look back in time and see what I've previously posted :)
How's the weather? where you live. Sometimes temps. and lenght of daylight play a roll. Low 80's and 12 hours of light
Also placing another male in the mix, sometimes spurs on competition for a mate.
You can try feeding, as added variety. Their mouth part can't bite anymore than a crickets. I only stay away from the kissing beetle family's with their piercing proboscis beaks.
If I was really mean, I'd tell you to place the beetle in your hand and press down with other hand. Now release the beetle and place hand in front of nose and breathe deeply.
I would avoid using broccoli, and cauliflower too much. Carrots are used widely. And while no nutritional value in celery it can be used to hydrate the crickets, with the water stored inside the stock part of celery.
Try mustard greens, and a little chopped up butternut squash.