Perplexing molting question

[Keith]

I witnessed a medium-large dubia nymph molt from start to finish. When it first emerged it was swollen and the body length was very long (it looked like an adult female size). I checked on it hours later, it was now flat, and the body length had shrunk to half its length it wasnt as long anymore. I was fooled it had molted to an adult, but it looks like it might be a sub-adult nymph now.

I think I know why the bloating, that was air to expand and split the old skin, right? But why at first was the body long, and over an hour shrunk to at least half it's "emerging" length? Was that basically how long it will be after it eats and grows more before it sheds next?

I think its temporarily longer because how else would a hardened exoskeleton grow with the nymph, the body is now "pre stretched" all it has to do is be filled and expanded by food now. Like a balloon, it starts off small, but when you add air (in this case food for the roach) it magically becomes much larger and stretches without breaking.

Sorry if this sounds confusing its hard to explain.

 

[Laura519]

My B. lateralis would do the same. I also noticed that they had a kind of seam down their back that would make them wider when they hardened than their previous form. Intriguing, no?

 

[Ticul]

Cool observation!

 

[Ralph]

When they molt they swallow a lot of air, which results in the elongated abdomen and helps them break out of the exuvia. Afterward they release the extra air and the intersegmental membranes relax back to the normal state.