Mosquito wing

Images made through a microscope. All subject types.

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NikonUser
Posts: 2676
Joined: Thu Sep 04, 2008 2:03 am
Location: southern New Brunswick, Canada

Mosquito wing

Post by NikonUser »

A short article in MicrobeHunter using wing scales to test lenses. Wings are far less dense than those of moths, useful for transmitted light. More images here:

http://www.microbehunter.com/wp/wp-cont ... n_2012.pdf

Image
NU12004
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

Mitch640
Posts: 2137
Joined: Sun Aug 15, 2010 1:43 pm

Post by Mitch640 »

I recently posted some pics of bug parts from some old cheap slides from the 50's. One was a mosquito wing like this. Later, I was discussing with someone, the use of diatoms to determine the resolving ability of lenses, and how mosquito or butterfly wing scales could also be used. Are the lines on the scales pretty much all the same distance apart?

NikonUser
Posts: 2676
Joined: Thu Sep 04, 2008 2:03 am
Location: southern New Brunswick, Canada

Post by NikonUser »

Not having a diatom slide I have no idea of the dot spacing. Butterfly and moths vary greatly in size and are likely to have different-sized scales.

The common garden/household mosquitoes (Aedes spp. and Culex spp.) are similar in size and likely to have same-sized scales.
As seen in your images of a mosquito wing there are 3 types of 'scales':

Those on the outer edges are long, wide and show very little contrast. On my slide I can count 11 lines, including the 2 outer edges, on a scale that is 15µ wide.

Those on the veins are shorter, less wide and show a high contrast; 6 lines in a 12.5µ wide scale.

The wing membrane is covered with tiny hairs, each about 5µ long and spaced in rows 10 hairs per 80µ.These show up as OOF dots on your wing (clear hairs on the wing shown in Microbe Hunter.)
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

Mitch640
Posts: 2137
Joined: Sun Aug 15, 2010 1:43 pm

Post by Mitch640 »

I also noticed on my slide, that the center was in focus and the edges not. Not what I expected from a Plan lens. Both the 20x and 40x PH lenses showed that.

discomorphella
Posts: 606
Joined: Sun Oct 01, 2006 7:26 pm
Location: NW USA

Post by discomorphella »

If you are curious, this old post
http://photomacrography.net/forum/viewt ... highlight=
has a few calibrated SEM shots of a diatom, where the pore pitch is approximately 0.5 um. THere are others with a pitch (measured with SEM) of ~250 to 350 nm (0.25 to 0.35 microns). These are right at the resolution limit for partially coherent imaging with your 1.4 NA objective at 550 nm (brightfield with your field diaphragm set ~0.7 of the full back plane of your objective, technically at 550 nm, or green light illumination). Although the mosquito wing is also a nice resolution target. I often set the high-dry objective's correction collar using a Cymbella or similar diatom if I am looking at aquatic samples.

David

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