Blue Death-Feigning Beetles-temperature and best ways to regulate it

[Aquarimax]

I recently obtained a Blue Death-Feigning Beetle. I am currently keeping it in a temporary enclosure with a largish desert Tenebrionid beetle ( likely an Eleodes sp. ) and a couple of smaller desert Tenebrionid beetles I collected locally. I would like to keep them in a desert vivarium in my cubicle at work. The problem is that the climate control is, well...not under my control, and the building is a little cool...my infrared temp gun gives readings of about 72-73 F, which isn’t too bad, but in winter, they are planning on taking it down to 68 F.

Do I need to provide supplemental heat, at least in winter? I have read conflicting information on this.
If it do need to provide supplemental heat, how should I do so? A side-mounted UTH seems inefficient for the amount of heat that will reach the beetles in such a well-ventilated container. A bottom-mounted UTH would only heat any inverts that happened tomburrowmdown to it, in which case it would be likely to do more harm than good. At least that is the case with millipedes.
I could use a CFL lamp above the tank, it would provide a little warmth, but is am not sure that is a good idea either. People,seem to have differing opinions on whether an overhead light is beneficial fo BDFBs...What are your thoughts? Here are 3 of the 4 beetles chowing down on some bug Burger:


Thanks!

 

[All About Arthropods]

No need to provide any additional heating, things can get rather cool even in the deserts where these are from in the fall and winter time so they naturally face cooler in nature anyway. In my previous house, temps used to even drop to the high 50s at the coldest times in winter and all tenebs were fine. Very nice beetles by the way! The larger one is an Eleodes hispilabris and the smaller I can't identify to species, but it is definitely Eleodes as well.

 

[Aquarimax]

No need to provide any additional heating, things can get rather cool even in the deserts where these are from in the fall and winter time so they naturally face cooler in nature anyway. In my previous house, temps used to even drop to the high 50s at the coldest times in winter and all tenebs were fine. Very nice beetles by the way! The larger one is an Eleodes hispilabris and the smaller I can't identify to species, but it is definitely Eleodes as well.

Thank you, @All About Arthropods, that is great to know the lower temps won’t affect their health. Did you see a significant reduction in activity levels at lower temperatures? Did they attempt to brumate?
Thanks for the ID! I was wondering if the larger one was E. obscurus, but now I know. I am lucky enough to live within a few minutes of good collection sites for Eleodes species...unfortunately I think I am too far north for Asbolus, but that’s what Bugs in Cyberspace is for.

 

[All About Arthropods]

Thank you, that is great to know the lower temps won’t affect their health. Did you see a significant reduction in activity levels at lower temperatures? Did they attempt to brumate?
Thanks for the ID! I was wondering if the larger one was E. obscurus, but now I know. I am lucky enough to live within a few minutes of good collection sites for Eleodes species...unfortunately I think I am too far north for Asbolus, but that’s what Bugs in Cyberspace is for.

No problem. My memory is a bit sketchy, but I may have actually kept a lower powered heat lamp over them that raised the temp up a few degrees now that I think about it, but it definitely got lower than 68 F at times. I don't remember too much, but I definitely don't recall any trying to brumate.
E.obscurus was a great guess considering that it is the most similar looking Eleodes sp., but they are a bit larger and more flattened in appearance. Very nice! It'd be my dream to live near deserts and be able to appreciate all the amazing microfauna that they bring by simply stepping out of my house.