Sample Preparation

With my new setup, I am starting to get remarkably detailed images of arthropods. Better yet, since I am still working out the details of how the system works I expect them to improve quite a bit over the next few weeks. If I don't already, I expect to have the photographic capability to create identifiable photos of most arthropods in the near future when I get a 10X microscope objective.

What I very much do not have though is the knowledge and skill to prepare samples and know what to photograph to ensure I have the correct details for an ID to be made. In the case of ants, I was given this wonderful guide that at least gives me a road map to get where I need to be. It really looks like with it and my setup I should be able to get identifiable photos of most ant species if I take the time to properly prepare them.

Other arthropods look more tricky. In particular, it appears that I will need to pick up a few more important skills such as dissection and slide mounting. Does anyone have good guides for what I would need to do to properly prepare flies, wasps, spiders, aphids, mites, leaf hoppers, beetles, or similar small arthropods? Ideally, I would like a set of procedures which I could follow to be sure I had and all the correct photos of it for an expert on that taxon to be able to identify it to species and a properly preserved specimen in case it is something special. At the moment, I have no idea how difficult this will be, but it seems like for at least a few of those groups it should be something I can learn to do with a bit of practice.

@silversea_starsong @borisb @edanko @rjadams55 @psyllidhipster @bug_eric @treegrow @cedric_lee @gcsnelling @robberfly

Publicado por glmory glmory, 01 de janeiro de 2017, 10:45 PM

Observações

Fotos / Sons

What

Formiga-Vermelha-Do-Fogo (Solenopsis invicta)

Observador

glmory

Data

Dezembro 28, 2016 09:04 PM PST

Fotos / Sons

What

Mosca-Do-Vinagre (Drosophila melanogaster)

Observador

glmory

Data

Dezembro 30, 2016 09:55 AM PST

Descrição

Since the Photoshop was so extreme, I decided to post all the intermediate images for the one image. First 34 photos were stacked in Zerene stacker and some basic retouching was done. Then I removed the point in Photoshop.

Fotos / Sons

Observador

glmory

Data

Janeiro 1, 2017 02:15 PM PST

Comentários

You may wish to contact UC Riverside for advice on entomological specimen/sample preparation. I know that a alcohol mix is used to preserve several arthropods, although I never learned where you buy such alcohol, what type of alcohol you need (there are many), and how it is used. Sadly the only responses I've received in the past have been "it's easy, just look up a guide online".

Publicado por silversea_starsong mais de 5 anos antes (Sinalizar)

Hi there,

I can give a couple of recommendations. Regarding alcohol, you generally preserve them is 75% ethyl alcohol (EtOH), but 70% which can frequently be found in pharmacies can be used in a pinch. try not to use isopropyl alcohol for extended periods because it tends to make the specimens brittle. Lab grade EtOH can be purchased relatively inexpensively through BioQuip (home for all your entomological supplies!). One thing to know is that when I mix it myself to the proper dilution using my tap or well water, it often forms a white precipitate in the liquid. I let it sit for around 24 hours and then slowly pour it through a coffee filter in a plastic Melitta coffee cone to get crystal clear liquid.

When preparing spiders, try and get photos of the living beastie because their colors change in EtOH and it would be great to better match a photo the living spider to a confirmed ID. In addition to multiple photos of the living spider, you want include (if possible) from the preserved individual, pictures of its eye arrangement, both from above and front, the spine pattern on the underside of the tibiae on their front legs, and either the epyginum (females) or palps (males). To photograph the palp, it is often easiest to amputate the right (spider's right) palp so you can manipulate it and get shots from multiple angles. Bioquip sells tiny viles so the palp can kept with spider.

hope this helps!
RJ

PS - there are numerous guides to specimen prep, but Agriculture Canada published "The Insects and Arachnids of Canada Part 1; Collecting, preparing, and preserving insects, mites and spiders" (1977). I like this one quite a bit and there are more up-to-date guides at BioQuip.

Publicado por rjadams55 mais de 5 anos antes (Sinalizar)

Not much more I can add other than work on your ant mounting technique. Proper mounting of ants is critical for Id. At least you do not suffer from the too much glue syndrome so many folks fall victim to.

Publicado por gcsnelling mais de 5 anos antes (Sinalizar)

@rjadams55 The guide "The Insects and Arachnids of Canada Part 1; Collecting, preparing, and preserving insects, mites and spiders" ( http://www.esc-sec.ca/aafcmonographs/insects_and_arachnids_part_1_eng.pdf ) is exactly what I need. Some of the procedures are pretty intimidating, but it at least gives a place to start. It looks like slide mounting aphids, thrips, mites and springtails is not too elaborate a thing to do. I will have to look into it. Flies, small beetles and other small insects requiring dissection still seem ridiculously difficult. Might be necessary to hunt down a local entomologist and make them show me.

Spiders don't seem so intimidating. Still waiting on the ethanol though, is there a pressing need for photos both fresh and preserved? Or is taking photos immediately then preserving in case it is something interesting a good way to go?

Publicado por glmory mais de 5 anos antes (Sinalizar)

@gcsnelling How long do you leave the ants in alcohol before pointing? I left them for a few hours in 70% isopropanol but still had a heck of a time getting legs to stay down.

Publicado por glmory mais de 5 anos antes (Sinalizar)

Isoproyl tends to stiffen them as does higher concentration ETOH which does cause some trouble. You can leave them long enough to be confirmed dead then give a warm water soak briefly which will soften them some. Different ants vary in their difficulty in positioning. Pogonomyrmex is esp tough, Camponotus is fairly easy. For specimens which are difficult I would Position them accordingly and allow them to dry before pointing them.

Publicado por gcsnelling mais de 5 anos antes (Sinalizar)

This set of videos from the USDA is really good. I just watched through the one on aphids, and it goes step by step through everything you need to do to slide mount one properly:
https://www.ars.usda.gov/northeast-area/beltsville-md/beltsville-agricultural-research-center/systematic-entomology-laboratory/docs/sels-slide-mounting-tutorial-videos/

Publicado por glmory mais de 5 anos antes (Sinalizar)

It sounds like trying warm water is worth trying, so I will do that next time. I have an order of 95% ethanol and will shortly pick up some 70% ethanol so maybe this problem will go away once I am not using isopropanol .

Publicado por glmory mais de 5 anos antes (Sinalizar)
Publicado por edanko mais de 5 anos antes (Sinalizar)

@rjadams55 Don't have ethanol yet, but tried taking the pictures you described of a small female spider. Probably should have chosen a larger one to start with, but the only larger one I found was a brown widow and after my previous experience I kill those on sight.

http://www.inaturalist.org/observations/4882251

is more magnification on the epyginum all that would be required to be sure to have enough pictures to be possible to ID to species?

Publicado por glmory mais de 5 anos antes (Sinalizar)

@edanko that is a neat site!

I get the feeling that is a minimum needed for a probable ID, not the total sum of photos to be certain to have an ID. Some of the other links describe dissection techniques which seem like they need followed for the more obscure species. Things like dusky lady beetles and many flies really sound like they need dissection, but I haven't found a guide that gives me enough confidence to try. Probably will need to squeeze some more resolution out of my system before it is even worthwhile though I suppose.

Realistically, I have enough information from this thread to keep me busy a few months though. I just ordered ethanol and an insect slide mounting kit which should keep me busy: https://www.bioquip.com/search/DispProduct.asp?pid=6385

Publicado por glmory mais de 5 anos antes (Sinalizar)

Great comments. Learned more here in a day than I have in nearly 4 years. What is the 95% ethanol for though?

Any entomologist specializing or even handling beetles at all could probably help you in the ways of preparing dissection slides for beetles (including ladybeetles).

Publicado por silversea_starsong mais de 5 anos antes (Sinalizar)

I also recommend not entirely limiting yourself to photographing dead specimens -- the living photos may be less useful in ID, but they are arguably more beneficial in the long run. The quality of "living" is a very special thing and you can't capture the real significance of an insect when it is dead.

On the other hand it isn't worth risking escapees :)

Publicado por silversea_starsong mais de 5 anos antes (Sinalizar)

Yeah, when I am not so excited to figure out something new I still have more than my share of live insects. In the case of ants, I have been taking live photos then taking an ant home for some time. That works well since I can tag the location and time more accurately. It just seems like I have what I need to produce identifiable photos of lots of really tricky stuff so I should be doing so. Also, a lot of what I have been photographing I caught by putting out a yellow bowl of soapy water. So there wasn't much opportunity to photograph them alive.

95% ethanol is the only strength BioQuip sold. I figure I can get 70% locally. I needed it both for preserving arachnids and as a step for slide mounting things like aphids.

Publicado por glmory mais de 5 anos antes (Sinalizar)

That is a difficult one because it was likely an immature without a fully developed epigynum, but with regards to magnification, it looked good. In a great deal of the arachnological literature spiders are described based on the structure of their reproductive organs with little information provided regarding their appearance in life. This is not surprising as it has traditionally been the case that these spiders were only examined by a specialist after they had been in alcohol for quite some time, many years in some cases. It would be a fantastic contribution if you were able to photograph the living spider, at least with a dorsal shot, and then match that to species descriptions using the scientific literature.

One trick when photographing a cursorial spider is to slip it in the refrigerator for a few minutes. While it is in there, set up your shot with a model (a sunflower seed works well) as they revive quickly. Once your shot is set put the spider where you want it. You should have about 30 seconds before it begins to scurry off.

Publicado por rjadams55 mais de 5 anos antes (Sinalizar)

@rjadams55 OK, picked up some everclear (which in California is 75% alcohol) and proceeded to catch two spiders after photographing them. After they sat in ethanol for an hour or so I took closer photos.

The first looks to me like the photos turned out alright, as it appears to be a mature female it seems like it should be identifiable:
http://www.inaturalist.org/observations/4897620

Pretty sure the second is an immature male, so I don't think it is identifiable unless it is something common:
http://www.inaturalist.org/observations/4897621

Publicado por glmory mais de 5 anos antes (Sinalizar)

@rjadams55 I managed to catch a couple more spiders including my first which were male. I get the right photos for this one?
http://www.inaturalist.org/observations/4902275
Not sure if I need to cut off a palp, or make a better effort to hold it in a particular position.

Publicado por glmory mais de 5 anos antes (Sinalizar)

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