Ooth laying sequence

[kamakiri]

S.limbata ootheca laying pics from this morning.

Outer left side:

Placing left side eggs (3 per side):

Left center egg just placed (compare to frame above):

Interlayer and top/fine zipper exit foam:

Finish covering:

Finished ooth from the top (laid right to left in this shot):

This ooth has an estimated 6 x 20 layers or 120 eggs.

The sequence for a layer starts on one side with the outer foam.

Typically, 3 eggs were placed from outside to centerline (from above, they form a half of a chevron, pointed toward the mantis).

Fine exit foam and interlayer are placed. I cannot tell if this is really one operation or two, but I suspect it is one, with the hardening outer skin forming the hard part of the 'zipper'.

Those 3 or 4 steps are repeated for the other half.

The finishing and starting layers are just the same as the outer foam.

Notice how the cerci guide the process and are at most times on either side of the zipper.

 

[Peter Clausen]

If you are lucky enough to see her laying the next ootheca, what do you think it will look like? 6 eggs across again?

And what about other females of this species?

Very interesting observations!

 

[kamakiri]

Peter, for others of the same species I'm not sure if they're all the same 3+3. 1 out of the 10 latest looks much wider than the others. It is from a larger female and I wouldn't be surprised if it is 4+4 instead. For this individual, I do not see why the next ooth would be different than 3+3. Most of the successive layings I've seen for a given female are similar in size, except when feeding is changed. It will be interesting to dissect that wider ooth when it has hatched. Or I might be lucky enough to see the next ones laid.

 

[Peter Clausen]

I wonder why they choose the dimensions they do? Is there some internal calculator that says 120 = 6 X 20? Why not 8 X 15 or 4 X 30? Would you agree that the width of the oothecae are all approximately the same? If this were true, they might all be about 6 across, but vary in length depending on how many eggs the female will be laying. What do you think?

 

[superfreak]

this is a great thread! id say the width of the ooth would be dependant on how far the mantid can comfortably flex its abdomen to each side. the hypothesis would be larger mantis/longer abdomen = wider ooth? it'll be interesting to see if this is the case.

oh and nice pics!

 

[Rick]

Very interesting. I have often wondered why mantids lay different shapes.

 

[Katnapper]

Love the observation and pics!

 

[kamakiri]

I was thinking along the lines of what superfreak is suggesting. That female is a bit larger, and more arc makes sense. I think the only way to know will be to cut them open or watch a larger/wider one in the process. I'll take some pictures of the mantises with their respective ooths soon. I do have a couple of old hatched ones left that are like the smaller size. I'm pretty sure they will be 3+3.

And on another note, there is a fair amount of variance in the look of the ooths, even for ones of similar size. Laying on the cloth lids may also be a factor in going wider. Two of the other larger females just made a bit longer ooths. Pics will show best what I mean.

 

[kamakiri]

Here's a version showing the layers and 'chevron' order as I mentioned above.

 

[kamakiri]

Here are a couple from 10/14 am showing a section of 4+4 eggs being laid. Not the best pics, but I had a hard time getting a good shooting angle for this one.

These also show the sticks that I've mounted to the 'kritter keeper' lids that I've been using for S. limbata adult females.

 

[wero626]

Wow i think you took great pics cant wait till i get some of my mantid pics up... :lol:

 

[kamakiri]

This is one laid early this morning:

It appears that the eggs on the mantis' left side have the columns collapsing at the center and a new one started on the outside. This one appears to generally be a 3+3 layout where the left side is disturbed by making the turn due to the small radius of cup.