Cryptoglossa Surprise!

Well, this is interesting. Back in August, I received 4 Tenebrionid larvae from a friend that were all labeled as a certain species, however, only two of them ended up being of that species. The other two were apparently larvae of Cryptoglossa muricata, and I may be the first, (or at least second if Dean Rider beat me) to rear larvae of this species to adulthood! And it was completely by accident! 😂 

So, this story all began on August 8th, when I received the larvae. I kept them in deli cups filled with sand, and a TINY bit of coconut fiber mixed in, with a vertical humidity gradient, and fed them leaf litter and chick feed. They were shipped in warm weather, which wasn't fatal to them thankfully, but approximately 10 days later, on the 18th or 19th, I noticed that the spike in temperatures had caused one of the larvae to construct a pupal cell, where it was going to pupate "prematurely"... A week after that, on the 26th, another one of the larvae followed suit and also made a pupal cell. 😐 I was a bit dismayed by the inevitable small size of these two larvae when they matured, as I was under the impression that they were larvae of a species that gets quite large, but hopeful that they'd at least mature successfully into healthy, albeit tiny adults. 

The first larva spent around 17 days in it's pupal cell before pupating on September 6th. It's worth noting that at this point, my bedroom (where I keep all my bugs), had started cooling down to room temps during the day, rather than the 80s/90s it was reaching during the day in midsummer. So the development of that pupa happened at room temps, though it did construct it's cell and enter it's pre-pupal stage when it was still rather warm in my room. 

Pupal cell and pre-pupal larva

The second larva was doing OK in it's pupal cell, but at some point, maybe a week after it constructed it, I accidentally caused it's pupal cell to partially collapse while watering it's deli cup, and so a few days after that, I dug that larva up and placed it in an artificial pupal cell of sorts. Much to my surprise, the seemingly immobile larva suddenly sprung to life and started burrowing quickly. Evidently, larvae of this species don't enter their completely immobile, pre-pupal stage until they've been in their pupal cells for quite some time... 

So the next day, September 20th or so, I decided to move it to a deli cup, where, instead of the pure sand I'd been keeping them on, I made the bottom inch of substrate a 50/50 mix of sand and coconut fiber. I thought that this would make it's future pupal cell stronger and more resistant to collapsing. However, the larva was seemingly unable or unwilling to use that medium to construct a pupal cell in. So, sometime last week, (forgot to note the date), I redid the deli cup one last time, changed it back to an all sand substrate, and low and behold, it's made a new pupal cell, which I'll do my best not to collapse this time. 😅

The second larva, shortly before making it's first pupal cell

Anyways, backtracking a little bit, that first larva to pupate on September 6th took around a month to develop, (perhaps because it was kept rather cool as a pupa), and finally eclosed on October 4th. I checked the deli cup it was in, and was startled to see it's pupal cell had completely collapsed. I dumped the contents out, happy and confused to find the adult beetle completely intact, but not at all the species I had thought it would be... I instead had an adult beetle of a species that had quite possibly never been reared before in captivity, and one I never actually thought I'd keep myself. Cryptoglossa muricata, one of the black death feigning beetles! 😮

Teneral adult, 10/4/20

Teneral adult, 10/13/20

The adults of this species seem to take FOREVER to fully harden and darken, which, considering their exoskeletons are SO hard and thick, makes sense that it'd take longer to harden than those of darklings with more thin, brittle exoskeletons, like some Eleodes spp. It's been 12 days, and this adult C.muricata has yet to darken fully, it's still a dark red color. I think it has been eating the chick feed I've offered it, so it's hardened enough to eat at least. 

BTW, shortly after realizing that these two larvae had actually been of Cryptoglossa, I did move my other larva into a much warmer spot, which will hopefully speed up it's pupation and get it developing quicker than it's sibling. 

Now, how did this mix-up happen? I honestly don't know, while the tank that my friend had been keeping her darklings in WAS a mixed tank, there were apparently never any Cryptoglossa adults in there, and so she thought all the larvae in there were from the other darkling species I had wanted... 😂 She still doesn't know how on earth any Cryptoglossa larvae could have gotten in that particular enclosure, but somehow they did, and since they look rather similar to the larvae of the other species in that enclosure, we were both none the wiser until this first larva matured. 🤣 An interesting experience nonetheless, and I hope I get lucky and end up with a sexed pair of this species, as now I'd like to rear larvae from egg to adulthood myself, so I can say I've successfully bred and reared at least one death feigning beetle species. 😜

Anyways, that's gonna do it for this post, I'll be sure to keep you all posted on my two individuals, hopefully this adult darkens soon so I can get some pictures of a fully darkened C.muricata! Thanks for reading everyone, take care, stay safe, and I'll see you all next time! 😉