Saturday, February 3, 2018

Third Molt... Our Empyreuma affinis Babies Are Fourth Instars!

As of our last writing, the majority of the spotted oleander caterpillar babies had already begun the period of inactivity which indicates the beginning of a molt. 

During this period, their body is producing an enzyme that will dissolve the interior portion of what is soon to become their old skin.  Also, their old head capsule, although still on their  head like a mask, has also separated from their old skin in preparation for the crawling out. 

Knowing this, explains why we were able to see a change in the head area and also able to see the new hairs matted underneath the soon to be old skin.

How does a caterpillar know when to molt?  It appears that there is a chemical secreted from the brain.  This 'Juvenile Hormone' as it is sometimes called when referring to the larvae (caterpillar) stage, tells the body to do the same thing but make it bigger. 

One research study has found that what triggers this hormone is oxygen depravation.  It seems that although the caterpillars body can grow its respiratory system cannot and when the body begins being starved for oxygen, the brain triggers the release of the Juvenile Hormone and the molting process begins.  With that process comes a larger respiratory system.

Pretty cool, right!

Cat on top is still overstuffing (this is typically when we see the super bright neon orange color) and Cat on bottom minutes from molting.

Cat on top molted earlier (the hair length has become easiest way to know) and has begun devouring leaf his sibling is preparing to molt under.

Hey, don't mind me, I'm just busy trying to molt down here!

Darlene came home from work to see the cats new container and commented that they were moving up in the world.  While that is true, the reality of it is that the cats have all seemed to go their own way on this last molt and the normal swap the old for the new  just wasn't going to work.  So, a container big enough to hold the fresh cuttings for the already molted ones as well as the older cuttings that some cats were still molting on (because they should not be moved when molting).

As of this writing, number nine is still a third instar while his siblings have all reached fourth.  He's been gorging on the new leaves though an should molt tonight.  He is currently measuring a full 1/2" while his siblings are twice that size.  He's got a long way to go and it is curious just how the process of becoming the Spotted Oleander Moth will go for him.

Speaking of.... here's a compiled video of the molting process that Nicole put together.  Turn on your volume if you want to hear the music and enlarge it to full screen for better viewing.  Enjoy!