Aphid Identification II

Since the last description of the techniques I have been using to identify aphids I have greatly improved my techniques. Therefore in the unlikely event that anyone is interested in doing similar on aphids or other species I thought I would describe my current methods

The first change I made was moving from Euparal, to Canada Balsam in a method close to the method described on the Aphid Trek website. The new technique consists of:

  1. Poke the aphids with an insect pin, then put them in a ~10% sodium hydroxide solution for 12-24 hours. I am not real scientific here, and just dump some crystals into distilled water until it looks like about 10%.
  2. Squish the aphids as shown in the USDA video
  3. Put the aphids back in a new ~10% sodium hydroxide solution. Usually I heat them up to ~50C for two hours, but depending on my schedule I may leave them at room temperature for 12-24 hours.
  4. Put them in 70% alcohol for two hours or longer. I have been using tiny beakers for this purpose, although the Aphid Trek website pointed me to contact lens cases. Those are way more convenient so I will be moving to those.
  5. Repeat the same process with 95% ethanol.
  6. Repeat the same process with clove oil. I just bought the cheapest clove oil I could find on Amazonand it appears to do the job.
  7. Spread out some Canada Balsam on a slide and position the aphids. This is by far the most difficult step. Moving the aphids into position is really difficult. I use an insect pin to push them around but this isn't as easy as it sounds. I learned that using orange oil to make the Canada Balsam flow better made it easier to position them. Still though, I am always breaking off legs or antenna. Ideally I get an aphid on its back with intact legs, antenna, as well as a visible cauda, and head. I learned that putting 5-10 aphids on a slide greatly increases the chances I get one right.
  8. Put the slide coverslip on, and let the slides sit for a few days at room temperature. It would be better if I could heat them, at room temperature it takes weeks to months to actually be dry. Still though, after a couple days they can be worked with easily enough.
  9. Photograph using the same process as my last blog post.

The second main change I made was to add better scale bars. This is because aphid ID is so dependent on comparing lengths of various body parts. First I learned to make scale bars. I found that really wasn't enough though. What I needed was actual measurements the photo. So I use Photoshop to measure the relevant parts, and make custom length scale bars to put right next to the parts. This is really inefficient, someday I need to find a way to more easily label a bunch of lengths in a photo. Still though, it works.

Even with all this trouble I am only able to identify perhaps two thirds of the species I find. Sometimes the problem is poor slide mounts, but the rest seem to be divided between poorly described (undescribed?) species and species that I lack sufficient magnification to ID.

Being an Engineer, I am always game for fixing a problem with more complicated gadgets. So I just put in an order for a Labophot microscope, a phase contrast condenser, and a 10X phase contract objective. That should give me enough magnification to identify almost anything. If that fails, it would be easy enough to procure a 20X, 40X, or 100X objective.

Posted on 27 de agosto de 2017, 06:14 PM by glmory glmory

Observações

Fotos / Sons

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glmory

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Julho 12, 2017 08:09 PM PDT

Fotos / Sons

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glmory

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Julho 12, 2017 08:30 PM PDT

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glmory

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Julho 15, 2017 11:46 AM PDT

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glmory

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Julho 15, 2017 12:46 PM PDT

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glmory

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Julho 29, 2017 12:43 PM PDT

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glmory

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Agosto 3, 2017 08:34 PM PDT

Fotos / Sons

What

Pulgão Roxo da Roseira (Macrosiphum rosae)

Observador

glmory

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Agosto 9, 2017 07:28 PM PDT

Fotos / Sons

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glmory

Data

Agosto 12, 2017 03:44 PM PDT

Fotos / Sons

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glmory

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Agosto 12, 2017 02:04 PM PDT

Fotos / Sons

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glmory

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Agosto 18, 2017 08:12 PM PDT

Fotos / Sons

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glmory

Data

Agosto 19, 2017 08:25 AM PDT

Fotos / Sons

Observador

glmory

Data

Agosto 22, 2017 06:01 PM PDT

Comentários

How much money on equipment and supplies would you say you've spent so far on aphid identification?

Publicado por cedric_lee mais de 6 anos antes

Well, on the scale of bird lenses, underwater photography, or similar hobbies I am still not totally crazy. Also, as a mid-career engineer with no other hobbies I can get away with things which even a decade ago I would have thought crazy.

Still though, I will make a go at answering the request:

Camera: $1,000
Macro Lens: $1,000
Macro flash: $300
Stackshot: $500
Mitutoyo 5X and accessories : $500
Assorted slides, chemicals, ect $150
LaboPhot with condenser including bright field, dark field, and phase contrast and a 10x objective: $425.
Photoshop, lightroom and Zerene Stacker: $400

Now drawing the line on what was to ID aphids, is a bit harder. The camera in particular I probably would have got for photos of kids. So the total budget for this hobby is about 4k. Only the stackshot, microscope objective, and microscope can really be said to be for identifying aphids though.

If I was more price sensitive a few components probably could have been bought used, and in particular a good camera is really not a requirement but I got some pretty good deals on microscope components so that part is paying rock bottom prices.

Also, a lot of this stuff has extremely good resale value. The microscope components I am buying are decades old and are unlikely to depreciate much further. So if I got out of the hobby I could liquidate with a large percentage of the initial cost.

Publicado por glmory mais de 6 anos antes

Thanks for the breakdown! I don't think I'll be getting into that anytime soon.

Publicado por cedric_lee mais de 6 anos antes

Haha, probably wise.

The actual making of slides is not all that expensive. The expensive part is producing images of high enough quality to measure lengths and numbers of hairs. So if you at some point have access to a good microscope than it might not be such a ridiculous hobby to take up. If you are building a home lab though, it is pretty ridiculous.

Publicado por glmory mais de 6 anos antes

If someone wanted to enter aphid identification on a budget, the way to do it would probably be to ignore slide mounting. Just photograph aphids in alcohol.

Influential Points has lots of such photos. This link has some examples.
http://influentialpoints.com/Gallery/Aphis_callunae_heather_aphid.htm

Will be somewhat limited in more extremely diverse genus, and keying out will still require a way to measure. This could always be done with a ruler on the screen though. It could probably be done with your slug setup, and maybe a microscope slide with a well which aphids could be imaged in.

Publicado por glmory mais de 6 anos antes

@glmory : thanks for this very intersting experience sharing.
I found the USDA videos you mention particularly useful.
Note that they have now been moved to a different url :
https://www.ars.usda.gov/northeast-area/beltsville-md-barc/beltsville-agricultural-research-center/systematic-entomology-laboratory/docs/sels-slide-mounting-tutorial-videos/

Publicado por gillessanmartin mais de 1 ano antes

Thanks! At some point I noticed that link was dead but didn't find the new one.

Publicado por glmory mais de 1 ano antes

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