Hissing cockroach horns growing without shedding

Keith

Keith

Megaloblatta
I have an older nymph that had been denied proper nutrition for prolonged time and near starvation, it's getting great care now and nutrition.

Its a male, and it had no horn bumps young males have, but over the weeks even though its fat and ready to shed soon, it suddenly has horn bumps and they slowly are getting wider and taller.

I thought the bumps only can grow after shedding, how is it bumps are growing without shedding? Is it like calcium growth like our fingernails? If this is possible than perhaps mature male hissers horns can get slightly larger over time!

 
No. An insect's outer exoskeleton is essentially "dead". There is no cell division, thus no growth in the pro and epicuticle. Secretion of new cuticle occurs at the epidermis, under the old layers of cuticle. Internal tissues can grow and insects have softer portions of their exoskeleton that allows for some expansion (between segments and such).

But as for a nice hard sclerotized pronotum - no, it's not growing. I suspect that your hisser may be eating it's exoskeleton. I have a few giant cave roaches that did that for several molts. The only way I knew that they molted was their brighter/cleaner appearance and a slight increase in size.

 
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windward said:
No. An insect's outer exoskeleton is essentially "dead". There is no cell division, thus no growth in the pro and epicuticle. Secretion of new cuticle occurs at the epidermis, under the old layers of cuticle. Internal tissues can grow and insects have softer portions of their exoskeleton that allows for some expansion (between segments and such).

But as for a nice hard sclerotized pronotum - no, it's not growing. I suspect that your hisser may be eating it's exoskeleton. I have a few giant cave roaches that did that for several molts. The only way I knew that they molted was their brighter/cleaner appearance and a slight increase in size.
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The first part makes sense, however I'm 100% sure it hasn't shed yet its same size and color and white stripes are still present. What I think is happening is horns are developing under the old exoskeleton giving it the raised bumps, its ready to shed very soon so that means when he sheds he will finally have horns!

 
Keith said:
What I think is happening is horns are developing under the old exoskeleton giving it the raised bumps, its ready to shed very soon so that means when he sheds he will finally have horns!
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The new cuticle layer is only secreted shorty before molting and the pronotum wouldn't be flexible enough to offer space for any growth in the meantime.Plus the new cuticle layer under, even should he be ready to shed tomorrow, would not be firm enough to push up the old.I think he just snuck a molt past you. Once you gave him enough food his body would rapidly put it to use.

If you don't have an undergraduate level entomology textbook (introductory level) you should consider getting one. Cheap used textbooks can be found online on amazon's market place or half-priced book's market place. The benefit of a introductory text over looking stuff up online is that all of your terms will be defined and you'll have labelled illustrations.

 
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Yes, that one is very good. I will warn you though, physiology and development is fairly thoroughly discussed and thus makes it aimed at someone who at least has had a college biology course or two. This text also includes some basic information on aquatic insects, parasitism, and various interactions. Its a bit light on taxonomy, though.

If you want dichotomous keys down to family level of several orders, than you would want something like Borror and DeLong's text - but that one is $200+

If you go with Gullan and Cranston pick up a used copy.

 
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I'm not imagining things, pronum is developing more without shedding! I can't explain how or why nothing in any book explains it as I've got entomology books and a book on cockroaches, Unfortunetly they don't discuss the long term effects of malnutrition and how the body recovers from it.

Not only are the bumps getting larger the curved area between the horns is starting to raise, I know it didn't have that a few days ago and I know it hasn't shed because its alone and it wouldn't be the same size it would be larger plus it still has the white spots which proves its still immature its vanwerbecki Hisser. I wish I had a photo the day I found it and now to compare you'd see what I mean !

Don't cockroaches secrete a waxy coating the repels water? When I found him he was dull gray and not shiny, over time he became shiny black and smooth, perhaps this coating can build up over the exoskeleton? I had a roach bleed by the pronum and it healed over time and a piece that got chipped had sealed up and eventually a thin layer covered it up , as if part of the exoskeleton regenerated as it was an adult roach, explain that in your book!

 
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