Anything from a gallon shoebox to a large 5-10 gallon tank works well as a breeding container, I'd say 12-20 adults per gallon is a good limit. 1-3 inches of substrate, preferably fine sand, is recommended. Unlike most other Cryptoglossini these appear to highly prefer very fine sandy substrate, perhaps fine clay mixed in would be fine as well. Hides in the form of cardboard rolls, cork bark tubes, cholla wood, etc. should be provided for the adults.
I recommend keeping only a quarter of the substrate humid, the rest bone dry. This species absolutely despises high humidity, unlike some other Asbolus/Cryptoglossa which enjoy higher humidity (at least as larvae). High ventilation levels are recommended as well.
Larvae can be quite cannibalistic, so for optimal survival rates, rearing them separately is best. However you can get a decent amount of them reared up to a large size communally just by burying LOTS of food in the substrate for them (in the dry end of course, old buried food in humid substrate is a grain mite paradise).
Should you choose to separate the larvae, I find they can be reared to a mature size comfortably in 2-5 oz deli cups filled with sand about an inch deep. Ideally you want a corner or the very bottom layer of substrate to be humid at all times, but the majority of the substrate should be kept dry. Excess humidity can quickly kill larvae.
Diet:
A staple diet of dog/cat/fish food works well for all life stages. They also enjoy feeding on dead dried invertebrates, and larvae will nibble on leaf litter if provided (but it's not a necessary component of their diet). Larvae prefer their food to be buried, as they seldom come to the surface looking for food unless they are absolutely starving.
Temperature:
It seems the most optimal temperature range for breeding and fast larval growth is around 75-80F°, though temps a bit lower are OK too. Mature larvae seem to need temperatures 78-80F° or higher to induce pupation.
Breeding/Life Cycle:
Adults live at least 2-3 years, and lay eggs year round, though seemingly in spurts of a couple dozen eggs per female, with 1-2 month pauses in between. Their eggs are very large in comparison to their bodies, and are always laid in the driest parts of the substrate. They're also rather fragile, and should not be disturbed or handled, lest you risk rupturing them.
The eggs hatch after a few weeks into grubby little larvae, that quickly molt and become a bit more mealworm looking (though Asbolus larvae have much thinner, softer exoskeletons than those of Tenebrio, Eleodes, etc.). If kept fairly warm and fed frequently, they'll reach mature size in only 3-5 months on average.
Mature larvae seem to require temperatures of at least 78-80F° to induce pupation. They should be given several inches of compacted substrate, the increased depth will helpt to improve substrate stability. Mixing in a small amount of clay into the sand, at least in the lower layers of substrate, can be beneficial to improving stability as well. This is important, because the main difficulty with this species is their substrate and humidity preferences leading to pupal cell collapses.
They prefer a substrate mostly comprised of sand, my own attempts inducing pupation in more organic substrate types have all failed, I've only gotten them to construct pupal cells in sand, or sand mixed with a small amount of clay. However, they also only like their pupal setup to be semi-humid at most, and die rapidly if kept overly humid. This is a bad combination, because sand based substrates that aren't fairly humid tend to collapse very easily. If the pupal cell of an Asbolus larva collapses more than once or twice, they usually don't make another pupal cell, and just die.
So overall, getting the temperature, substrate composition and humidity levels all perfect for the pre-pupal larvae of this species is a difficult task indeed, because of this these are one of the most finicky Cryptoglossini to rear in my experience. Ironic, considering the adults are some of the most prolific I've ever kept, and the larvae themselves are very easy to rear too.
If you do get everything just perfect though, the larva will scratch out a pupal cell at the bottom of the cup, and remain in there in a pre-pupal state for 3 weeks to over a month, and then pupate. The pupal stage only lasts 3 weeks or so, maybe less if kept very warm. The resulting adult can be removed from it's pupal cell once it's turned a dark orange color, and should be placed in a well ventilated deli cup, with a thin layer of substrate, one corner kept humid, the rest bone dry. Food can be offered, though it might not eat much until it darkens and hardens up further.
1-2 weeks later, the adult should be darkened and hardened enough for introduced to the main breeding enclosure safely, and the cycle begins again.
