Learning to make and use aspirators has been key in doing certain surveys. Recently i used the aspirator to collect a spider from my ear: https://www.inaturalist.org/observations/74107412
@kiwifergus what is a sit-still?
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A flour sieve for water beetles. A handful of dried-up pond mud for micro-crustaceans. I like all the ingenious traps people come up with for extracting insects from difficult habitats, such as pitfalls set in a platform to collect in scree, subterranean traps for certain weevils, and pumping groundwater out of river gravels and through a sieve for various little-known interstitial invertebrates, but I never get around to making them.
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I probably donāt need to say, but I will anyway, you then put the mud in a jar of clean water and wait for things to hatch out.
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Iāll have to try that sometime.
Mine is a Petri dish, the bottom part having a piece of cling film stretched taut over the top of it and held in place by a rubber band. You expel the bug from your pooter into the lid of the Petri dish, then place the bottom on so that the cling film presses the bug to the lid. Do it slowly so the bug can adjust position of legs to better cope with being made to āsit stillā. Terrific for getting ventral views of spiders that normally never offer such views, and has the advantage of not damaging critical structures like trichobothria. Not good for slimy critters, or those that shed scales (like moths)
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Can see that working nicely, thank you.
Sweep net and aspirator/pooter for me. I collect diptera, and this is the best way to get good specimens. Of course traps are very effective, malaise, water etc. and I will use that too, but then we typically collect for wet storage, and I really prefer dry material. Traps will also result in catching all kinds of stuff that I have less interest in.
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Iāve tried this many, manytimes, but it seems that I pretty much always forget a detail, thus causing the tiny beetles to go into my mouth. Or I just forget something and it either falls apart when I need it most, or it just doesnāt work. Which is part of why Iām just going to save up to get on off of BioQuip.com, it will probably be safer on my part. Less swallowing of specimens that way.
I still prefer hand collecting.
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get some clear tube, about a metre (yard) long, cut a piece off the end about 100mm (4in) and then over the end of the long piece, place a piece of very fine mesh cloth (small holes, but allows air to pass through). Tape it to the tube so that you can suck the other end and air still goes through. Then place the cut off piece back, and tape it back in place, trying not to cover too much of the sides of the tube. This end piece is where the bug will end up when you suck on the other end.
I used a piece of tubing from a hospital, that had swellings every metre. I cut it at the swelling, where the internal diameter was the same as the external diameter elsewhere along the tube. Then I cut off the swollen part from the longer piece, placed over the cloth, and pushed on the shorter piece with its wider swelling. extremely simple to assemble, easy to use, easy to clean regularly. I hang it around my neck when in the field, and it is readily available when I need it!
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Another take on the homemade pooter: The smaller diameter tube at the distal end may help to increase the strength of the suction you create. The screen fits nicely here where the tippet (to shamelessly adopt the flyfishing term) joins the larger tube. Sometimes these tippet pieces can be lost, so I keep a few replacement ones handy. The different colored tubing that is used as the mouthpiece can come in handy as a last second warninig when you arenāt paying quite as much attention as you really should be and you go to suck on the wrong end, which, from experience, truly sucks. The in-line fuel filter is there to stop the very small unwanted items that might get thru the screen. The person who showed me this addition related a story about a researcher using aspirators within caves who was aspirating a lot of specimens off scat, and had some things pupate in his sinuses, as i recall. Anyway, it seemed like a good addition after i heard that. Screens to use can be inexpensively obtained from paint strainers, that are like 0.25 cents each at our local hardware store (as an example, https://www.amazon.com/TCP-Global-Strainers-Micron-Filter/dp/B000PA09V0/ref=sr_1_5?crid=30OIRFN9TWB14&dchild=1&keywords=paint+screen+filter&qid=1619380414&sprefix=paint+screen%2Caps%2C288&sr=8-5)
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The filter is a cool idea! For scat or any situation that might have volatiles that I donāt want to be inhaling, I would investigate options for attaching a small battery powered pump that can be easily turned on or off.
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I donāt think this has much of anything to do with this topic, but Iām just wanting to know if there is already a topic posted yet, that is not closed to new replies, for nature poetry?
If anyone could answer this, that would be great! Thanks!
Has anyone used CO2 for knocking out insects to avoid having to take specimens to ID?
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No, but I have knocked them out with small amounts of laughing gas, and with a 5- minute exposure to methyl acetate gasses.
And I have put them in the refrigerator to slow them down temporarily, long enough to get microscope pictures. It only lasts a few minutes, and then they are active again.
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Jasons technique of cooling in the fridge is probably the most common and insect-friendly choice. Iāve used amyl acetate vapours to gently puff into a spiders retreat to entice it out. Itās the chemical responsible for the smell of bananas, and itās heavier than air and somewhat cloying on the lungs, so the spider leaves the retreat until the vapours get absorbed into the surroundings. Ground based tunnelwebs especially this is good forā¦ zero damage to their silk retreat! For some spiders the internal female genitalia need to be examined under microscope, so not even CO2 would help in that case! At least with most male genitalia the structures required are for the most part visible, so itās technically possible to examine them with a live spider and then release afterward. Even then it can come down to having the exact angle of view to make the determination, which can be very tricy with an attached palp!
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yes, dissection essential atm in some cases if you wish to determine species of course,
and understand the need for taxonomists / other naturalists doing this.
I have killed specimens in the past but I remain uneasy with it though myself.
I have also refrigerated many times, but this doesnĀ“t work so well with some taxa (e.g. ichneumons). It also still feels invasive to meā¦and there are other reasons I donĀ“t really want to take specimens home. But this side of things is a different conversation :)
Overall I think being able to capture detail in the field just seems more optimal and suited to me.
But there are limits with complex taxa, photography and a moving being.
How have you delivered the gas?
I read some people saying they used CO2 capsules like this ā¦
I wondered about using it with a pump like this
Usually with a pressurized pump, similar to those in the link, but had either the fumes, or the CO2 in the little tank, barrel, canister, whatever the can-like thing is called.
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