Adventures in building science gear

I’m eager to start surveying and collecting spiders, so I prematurely made a Berlese funnel, a kind of filter for collecting small invertebrates from soil samples. I say “premature”, because I made it just before last week’s big blizzard hit, so everything inside refroze, and I’d also overloaded it with too much gunk. So reset: cleared it out and tried again with a smaller sample and warmer weather. It worked!

No spiders, though. Other little critters. I’ll be hesitant to jump into any leaf piles in the future, I tell you what.


  1. jrkrideau says

    Hey, I thought the tick was rather cute.

    This reminds me why living with botanists at university was interesting. Babysitting the second largest collection of carnivorous plants in Canada was challenging. And all in a small townhouse.

  2. lochaber says

    That’s pretty cool. the idea for the egg crate and plastic canvas carry over from aquarium DIY, or something else? (I’ve used both of those fairly frequently in aquarium projects.

    I wonder how the reflector from a second lamp would work as a make-shift funnel if you wanted a metal one. The volume would be a lot smaller, but it seems like that might only be an issue if you get the chance to use dry leaf litter.

    And what about the critters too big to fit through the holes, or are you mostly looking for the tiny ones?

  3. mikehuben says

    I’ve run funnels intermittently for 40 years. It’s amazing what you can get, but very difficult to identify even to family.

    I collected and identified more than 100 families of mites for my Acarology class at Cornell, most of them from soil samples, so I know how difficult it is. I can’t put a family on the mite from the video, but it is definitely not a tick, and likely in one of the many families of predaceous mites.

    You will get small spiders in funnels, and sometimes be surprised by a salamander or something else bigger than you expect.

    40 watts seems kind of high for a small funnel like that: 25 might be better. You can also cut metal window screening into a circle and support it with hardware cloth snipped to fit. But I was impressed with your wife’s steamer idea. When I made funnels, I made them out of sheets of cardboard. And your observation about the benefits of a flat bottomed collection container are spot on. As the sample dries out, some dirt crumbles and falls through, but some more might be kicked down by the moving insects and mites.

    You’re right that you need to use a thinner sample. Otherwise you don’t get the proper “eek, it’s hot and dry here” effect. You do need to be careful of a few types of samples: for example, the biting mites in a barn swallow nest more up towards the light and out of the funnel. The nastiest sample I ever did was cormorant guano; but the stink didn’t last too long.

    Entomologists now tend to use Winkler samplers instead because they dry pretty well in any environment with sunshine, don’t need electricity and are light and compact for travel. Here is a great design for $3 Winkler samplers (scroll way down to it) that I link to on my Entomological Methodologies page. I find that most entomologists, even professionals, don’t know or use a lot of these techniques. I’ve made these samplers, and they are really easy.

    Feel free to email me if you have questions.

  4. wzrd1 says

    @3, I’ve fallen toward studying tardigrades, eventually.
    First, finding the bastards.
    Thinking centrifugal filter.

    That all said, I’ll need a few microscopes, not a biggie, even for an older model SEM or TE scope.
    I was the champion of the TEM microscopes donated to us, one near state of the art, now, long gone.
    Along with the telescope.

    Now, chemistry is treated with a jar of M&M’s, reagents, that’s college.
    We worked with active chemicals, as appropriate, under a hood.
    In junior high school, I managed to isolate a problematic, unrealized at the time. pneumococcus, which health took great notice on and due to my youth, remains unrecorded. Don’t care, something potentially bad was addressed at that level.
    Alas, that lab got shut down, for some reason. ;)
    Yeah, we had incubators and donations of cultures.

    Currently, the school system lacks even a microscope, but excels somehow.
    I suspect M&M’s, they are tasty on occasion, or something.

  5. jack16 says

    From Wikipedia: A variation of the Berlese funnel uses naphthalene flakes or similar aromatic mothballs in place of the heat source to drive organisms downward.[4] This method finds application in situations without electrical power, where the organisms are repulsed by volatile preservatives in a collection container, or they cannot migrate downward quickly enough to avoid desiccation.

    Might try this variation as well.