Gromphadorhina portentosa colony trouble

[Neon765]

Hi everyone,

I currently have a Gromphadorhina portentosa colony, and had around 25 nymphs. It's been 4 months and a lot of them have grown a lot, however, in the last few days they are dying at an alarming rate and I can't seem to find out why this is.

I keep them at around 25°C - 30°C, the weather here is never too cold or too hot so I rarely use a heat mat - I feed them carrots, apples, cucumber, pumpkin, lettuce, celery and papaya. I mist the tank daily and use coconut fiber with sphagum moss as substrate.
They have been in good conditions all the time but for some reason they have started to die.

The tank does not seem to have any mites or anything. I just find them lying on their backs and they don't make it past 2 days.
The weird thing is that the oldest male of the colony, who is also the father, is alive and on perfect conditions, yet the nymphs are not.

I ask for your help because I have no idea what else to do, maybe I am making a mistake which I may not be aware of and is killing my colony.
Please, if you were so kind to give me advice, any suggestion will be useful for me right now. For the moment I will try to buy new substrate from a new source and relocate them again, hopefully this will keep the ones that remain alive so they can breed again.

Thanks for your help

[kevinkk]

After looking up the Latin, not many here raise roaches , there is a site you might try- "beetleforum.net"
Other than that, I'd say to clean out your tank and start over, just like fish, or anything else, once some lethal
unknown gets in, it's tough to get rid of without some work.

[adamcotton]

I saw the post in 'Presentation' which stated you are in Lima, Peru. I wonder, as an alternative to a pathogen, if your problem is due to inbreeding. It is likely that Madagascar cockroaches will be very inbred by the time you received stock in Lima, and that could be the reason your offspring are dying.

Adam.