Wednesday, January 31, 2018

From Second To Third Instar Spotted Oleander Caterpillars

We last left you on day six of our tiny caterpillar story.  Number nine was accommodating to his new skin and the others had started to enjoy some fresh greens and sunshine. 

Day seven was all veggies all day long and a lot of consumption was happening in these parts.

Beside the fact that they have now reached 5/8 of an inch, the biggest change is that our little ones are now eating right down the edge of the leaf and devouring whole portions of it not just the top layer. 

what goes in must come out so the end result (pun somewhat intended) is an obvious increase in frass.  The good news is that caterpillar poop is dry.  Or at least it is by the time Nicole cleans out their box.  It just all rolls together like sand and she pours it into the trash.  Something else that wasn't quite obvious until the cats (and their resulting frass) increased in size is that it is green.  Sort of makes sense when you think about it.

When we arrived home late on the evening of day seven our baby Spotted Oleander Caterpillars were given a whole new, fresh and clean set-up.  Although they nibbled a tad, they were not their usual exuberant selves in the presence of fresh food.

Although this one whom has now become known as number eight continued to chow down for a bit...

the other ones were beginning to look and behave 'funny'.  They were very puffy looking and they had all assumed the same position on the top of a fresh leaf. 

Do I look bloated to you?

At first, Nicole thought that maybe they were just going to team up on the leaf and eat the whole thing together like a little caterpillar party. 

However, they never moved and they never ate even a single bite. 

Instead they just sat there and in the morning they were still sitting there. 

This had Nicole very worried so on day eight she watched them intently.   She could see them on top of the leaf while she worked on her computer. 

Then, one time she glanced over and they were all gone!  She rushed over to their container and had to do a double-take because for a moment she thought that her world had literally turned upside down. 

The caterpillars had all moved to the underside of the leaf.  Almost like clockwork it seemed. 

There they sat, not touching the new food she had just brought them.  Although she thought that perhaps they were getting ready to molt again, her worry continued because it was taking so much longer than it did the first time. 

Nicole got no sleep between day eight and nine because she kept getting up to check on the babies.  At one point she looked at them and they seemed dark.  This was a cause of great concern as dark in cats or eggs usually means 'the end'.  

It should be mentioned that while these eight were for all appearances suffering a great fate, number nine was thoroughly enjoying his solo buffet.

So, the runt will be the only one to survive, she thought.  Unexpected.

In the morning light she decided that the only reasonable thing to do was to take some macro photos and see if she could determine anything by looking on the computer. 

What she determined is that their darkening color was a result of being able to see their new body and crisscrossed tufts of new black hairs under the exterior shell they were getting ready to shed.

Their head capsules were also looking very clear and shining in the sunlight. 

This was a relief and quite a sight to behold and witness considering the first time they molted they were too tiny to gain a good view of the process.  This time, we were able to witness every aspect and it was fascinating.

We'll walk you through it as much as possible.  Since this was our first time with a good view of the process Nicole shot a combination of photos and video.  The video we'll share later.  Here's the photos.

Shew!  Fresh out of my old skin and looking like a 1950's greaser.  Time to pump my tail up and down for a little while and then like magic..

POOF!  My hair miraculously pops up into place.  Just like that!

Then it is time for a little wiggle dance. 

Wiggle.  Wiggle.  Wiggle.  I comb my new hair.  All while still hanging upside down, mind you.

The last thing I do is rub my head on the leaf to dislodge that old 'too small' head capsule.

Here it is, the old head capsule.  Just barely bigger than a pencil tip. 

Here's a great shot of the old skin (hair and all).  If you look closely you can even see where the cats legs were.

After good rest, the baby Empyreuma affinis caterpillars turn around and eat their old skin.  It usually takes many more hours before they are ready to start eating leaves again.

But once they are, they go about it in a ravenous way!

Yum, yum, yum.

A couple of days of constant eating and pooping and growing.

Lots of eating and pooping... and growing.

Just look at how beautiful we have become!  We are officially third Instars and well on our way to molting into fourth.

As of this writing, as Nicole checks the calendar and checks on the young spotted oleander caterpillars it appears that they are already preparing for their third molt.  Oh how time flies!

And, just how is number nine doing?

Well, we are finding some separation in our siblings.  On day nine seven of them molted all within about thirty minutes of each other and have immediately shown significant changes in size with the largest on being a full 7/8" and then some.   Number eight who is just slightly smaller than the other seven molted a day later on morning number ten. 

Number nine is still hanging in there and finally molted on the afternoon of day eleven.  Today number nine finally started moving around and showing himself and compared to the others still has some catching up to do.

The size differential is significant but since he is passing all of the expected molting milestones we hope that number nine will pull through to become a beautiful Spotted Oleander Caterpillar Moth (Empyreuma pugione).  Either way, it appears that had he been left to fend for himself in the wild, there is a good chance he may not have made it.


                                             And, that's the frass from our world...