Insects that have a complete metamorphosis (abrubt changes from larva-pupa-adult) develop, what I guess can be compared with stem cells in humans, groups of cells called "imaginal discs".
In mosquito larvae and pupae most of the internal organs break down into a liquid. Except that there are a few clumps of cells that remain intact, these are the "Imaginal discs" which give rise to the adult's tissues and organs.
Top: dorsal view of thorax showing one imaginal disc (red)
Lower: ventral view showing these discs more clearly.
the blue arrow points to the paired ventral nervous system and a segmental ganglion just below the arrow. (I think the nervous
system might be carried over from larva to adult).
Nikon 4x CF N Plan Apo on bellows; 20µ frames stacked with ZS.
NUM10126
Last edited by NikonUser on Tue Dec 14, 2010 9:29 am, edited 1 time in total.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
What you explain about the "imaginal discs" and the nervous system is very interesting! A few weeks ago I found a larva in a pot of plants on the terrace and we took some pictures swimming (may be shacking is best description) in a UV filter at low magnification as curiosity, rather like this is some Aedes specie? I think mine is Aedes albopictus, the "cursed" tiger mosquito that cause quite dolorous bites!
Some recommendation or link for try a specie identification?
Thanks Joaquim.
This larva was in a bird-bath, last Summer (July). It could be either an Aedes sp. or a Culex sp.
Sorry I cannot help with European ID manuals (I'm in Canada).
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
NikonUser wrote:Thanks Joaquim.
This larva was in a bird-bath, last Summer (July). It could be either an Aedes sp. or a Culex sp.
Sorry I cannot help with European ID manuals (I'm in Canada).
That is the "subject" and I think is very similar to your mosquito picture (mine is much worse):
Given that this is an asian invasive species (if that is a Aedes albopictus), which extends quite easily and I took the shot in early November would not surprise me that you saw out there shortly!
Joaquim F. wrote:n early November would not surprise me that you saw out there shortly!
Best regards
Joaquim
Not known from Canada. Anyway, it would not be flying here until at least May - very cold here in the Winter!
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
Hi John:
These larvae, and all insect larvae, have a full set of organs and muscles, such as a gut, breathing tubes, muscles to move the jaws, muscles to walk, and excretory system, etc.
None of these organs are carried over to the pupa and adult. Instead they are broken down to the basic building blocks such as proteins and fats and a whole new set of organs and tissues are developed.
But in the larva stage there develops clumps of undifferentiated cells (the imaginal discs). The cells in these discs (the white blobs in the photos) resist the action of the enzymes that destroy all the other tissues. It is these cells that that give rise to all the organs of the mature insect.
It's analogous to embryology where a ball of identical cells (in the blastula) give rise to all the different types of cells in the human body.
Just remember, one cell (a fertilsed egg) eventually divides into millions of daughter cells which form all sorts of tissues. Imaginal disc cells work in a similar fashion.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
This is the siphon (tail) end of this larva.
MT=Malpighian Tubules (=kidneys)
st: single group of bristles posterior to the pecten teeth makes this an Aedes sp. and differentiates it from the other very common local group of mosquitoes (Culex spp.)
Nikon 4x CF N Plan Apo on bellows, 6µ frames, ZS PMax.
NU10111
Above is a crop, full frame below:
NU10112
Last edited by NikonUser on Tue Dec 14, 2010 12:03 pm, edited 1 time in total.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
Thanks for the additional info and image NU – fascinating stuff!
The quality of that last image is wonderful! (Impressive how much magnification you can squeeze out of that 4x – is this cropped or are you using really long extensions?). The lighting helps highlighting the different parts – the MT in particular really stands out here.
If you'd ever decide to make an illustrated book on insect anatomy I'd be the first to buy it!
Thanks John.
I have added a full frame image below the original; shows food in the gut.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
