Adult cockroach shed, with bad results, and possible hermaphrodite nymph

[Keith]

One of my adult female dubia has tried to shed again, I would not have believed it was possible if I never saw it, but it's true. Sadly, only half her skin split so the other half is still on with no way to come off, and it looks like her insides came out for some strange reason. If she had done a full shed with no injury I see no difference in body parts other than slightly larger size, so no wings or any other odd body changes, she would have just been larger. I am not sure why this occurred, or if anyone ever had a adult roach do a full shed and live because that would be very cool to have and document!

I also have a dubia nymph that when you look at the wing pads the top right looks almost like a male wing pad and the top left female, what do you think?

[Keith]

Nymph

[Zephyr]

If you could flip that dubia nymph over so we can look at the sternites, that would be very helpful in determining if it's a gynandromorph or not.

As for your post-ultimate dubia molt, I have experienced this with other species with brachypterous adults. I've had at least two Byrsotria females attempt this before, both ending in failure.

I brought this up to Dr. Saarinen, an entomologist at the University of Michigan-Dearborn. She thought it was bizarre and semi-implausible. I have the specimen in my freezer so one day I'll open it up so her and I can examine it.

Dr. Louis Roth believed that the various extents of winglessness (in cockroaches at least) was a direct link to the extent of that species's paedomorphy, or retention of juvenile characteristics. Along with winglessness ocelli area was also thought to be related to the amount of paedomorphy. Where does this play in with individuals like your female dubia? Well, since there are mutations, and we raise roaches in unnatural environments, chemicals or a variety of other factors may influence our roaches, and they may bring out other juvenile aspects in roaches with some extent of winglessness. For example, though this is simply speculation, adult female dubias may have higher levels of juvenile hormone in their systems, which may in part control their development into paedomorphic adults. Chemicals in dog foods, or in genetically modified fruits/veggies may encourage more JH to be produced in their systems, and this would cause a roach with an already higher level of JH in its body due to its paedomorphism to be more susceptible to the effects of JH, which includes ecdysis.

Simply speculation, as stated before; this may be a fairly commonplace thing in wild dubia colonies, perhaps due to genetic anomalies or other unpredicted factors. Lots of food for thought and research too!

[Keith]

I would not say the females retain juvenile characteristics as they can reproduce and have 2 wing pads where juveniles have 4. Also what I don't understand is if these females have more of a juvenile hormone level, wouldn't they keep growing as nymphs and never actually molt into adults, and how can you have nymph hormones yet physically have mature reproductive parts? Also, why do all these specimens only manage to shed half of the skin and not the full skin like they should, it's almost like the shed hormone only reached half the body and started at the back instead of the normal way in the front.

[Zephyr]

I would not say the females retain juvenile characteristics as they can reproduce and have 2 wing pads where juveniles have 4.

Reduced ocelli and lack of wings are juvenile traits. If you were to lift those forewings you would find another pair of hindwings underneath them.

Also what I don't understand is if these females have more of a juvenile hormone level, wouldn't they keep growing as nymphs and never actually molt into adults, and how can you have nymph hormones yet physically have mature reproductive parts?

As I said, speculation. But higher levels of JH are associated with ecdysis. There are, of course, many other complex factors at work here, though it is interesting to note that the variety of castes found in termites are pheromone controlled as opposed to genetically hardwired. Termites are also capable of switching between castes in their early instars as well as performing stationary or regressive molts, the latter of which being something other insects can't do.

Also, why do all these specimens only manage to shed half of the skin and not the full skin like they should, it's almost like the shed hormone only reached half the body and started at the back instead of the normal way in the front.

The front end of the body is trapped not because of hormones reaching one end and not the other, but rather that the part of the exoskeleton that is contained within the wings is trapped because wings are not designed to be shed in 99% of insects, with mayfly subimagos being the exception.

[Keith]

Got ya now, never knew any of this about insects just goes to show there is always new stuff to learn.

I wish the gal had fully molted that would have been really special since all my roaches were bred by me, and I read about some tarantulas that lived from it.

From what you were saying about termites and castes, do you think this female was the dominant one of the colony and that perhaps made hormones to try and ultimate molt as a sign of dominance? Roaches are related to termites closely so mabye this is a reason for it?

Has any males ever done this, what about hissing cockroaches?

[Keith]

Here are the best back and underside photos I could get.

[MantisMan]

well the nymph looks like female and the reason tarantulas survive molts is because arachnids molt even after reaching maturity

[pierre72]

One of my adult female dubia has tried to shed again, I would not have believed it was possible if I never saw it, but it's true. Sadly, only half her skin split so the other half is still on with no way to come off, and it looks like her insides came out for some strange reason. If she had done a full shed with no injury I see no difference in body parts other than slightly larger size, so no wings or any other odd body changes, she would have just been larger. I am not sure why this occurred, or if anyone ever had a adult roach do a full shed and live because that would be very cool to have and document!

I also have a dubia nymph that when you look at the wing pads the top right looks almost like a male wing pad and the top left female, what do you think?

Oooo! Sorry to here that Keith.