Re: Cockroaches in Vivarium - Is this plan OK?
The trick is to place the trap up against the wall in a far corner, I like the trap and its position to enable a pen light peek. Leave it without disturbing for enough time for the roaches to habituate to it as secure harborage. The addition of extremely attractive food and warmer than the ambient situ will cause them to collect in a cluster of adults and nymphs taking significant dents out of the vivs roach populace with its retrieve.
To be clear, for those still apprehensive about UTH because of stories that if investigated to source will reveal either misuse or accumulative heat smother factors, be assured that an undamaged unit placed on a separate pane is placed close against the viv wall or anywhere from a few mm or cm, so that Warm Air is what is warming the spot. It isn't on the viv glass itself. This negates having to use a thermostat and keeps it versatile and portable, its condition and monitor clear.
You will not crack your tank with misting etc. If you are still nervous about it put a piece of cork etc.. but you are targeting the mid to upper 80s with your topical placement.
You may even note that darts will briefly visit warm zones in repose. But that's a whole other topic.