General Question

delirium's avatar

When pinning entomological specimens... How do you get a pin through a coleopterid's pronotum?

Asked by delirium (13681points) September 7th, 2010 from iPhone

It’s bloody hard to do! I’ve tried everything, from heating the needle to building a special harness to support the beetle so I don’t destroy its legs… Nothing works. I usually just end up pinning them through tergite I or II, but it’s a bitch to do without hitting the wings on adult specimens. The only other thing that I’ve found to work is pinning between the head and thorax, but that pushes out the head in an odd way and is quite fragile. Any tips?

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14 Answers

syz's avatar

What about superglue-ing the specimen to the head of the pin rather than piercing it?

MissAusten's avatar

Hmmm….When I pin beetles, I try to get the pin through the middle of the pronotum, which doesn’t seem to disturb the elytra. I haven’t had trouble with the legs breaking, but when I pin bugs they are freshly thawed from the freezer and tend to be pretty flexible. You sound much more knowledgeable about it than I am (wtf is a tergite?!) but it’s just a hobby for me and my son.

I tend to pin insects directly into my son’s specimen box, which has a styrofoam base with some “give” to it. I use some sturdy tweezers to help hold the beetle in place. It’s also possible that the beetles we collect here in CT just don’t have as thick of an exoskeleton. Once I get the pin where I want it, I use additional pins to position the legs and antenna, then later remove those pins once the specimen has hardened.

Don’t be impressed, I had to look up the word “pronotum” but did know elytra already!

MissA's avatar

@delirium I don’t know about pinning bugs, but I do know a bit about pins. Are you certain that your pins are as sharp as they need to be?

One way of sharpening all pins is to run them through your hair one way, then repeat. They’ll go through anything. I’ve taken lots of antique pins, losing their metal and have done the same things. Worth a poke…pun intended.

gondwanalon's avatar

If you want to make your Coleoptera specimens look great and you have a Dremel tool then you can use tiny Dremel drill bits that are as thin as a standard size insect mounting pin. Check out your local hobby shop or Home Depot. Carefully drill through the dorsal aspect of the area in which you would like the pin to go through (typically the left side of the thorax elytron). With this method you can easily mount a rhinoceros beetle.

Amazon dot com also has tiny jeweler drill bits (cheap) tat fit a Dremel.

gondwanalon's avatar

I ment to say that the pin is typically the RIGHT side of the thorax elytron.

delirium's avatar

@gondwanalon Awesome! Only question is what a thorax elytron is? I’ve never heard that term. You mean the meso-thorax?

gondwanalon's avatar

The elytra are the thick horny Coleoptera front wings. They cover the membranous wings and usually the entire thorax and abdomen as well.

delirium's avatar

That wasn’t my question. I know what the words mean individually, I am quite educated in entomology, I just have never heard the term “Thorax-elytron” before. The elytra don’t cover the thorax entirely, they start posterior to the prothorax.
I just don’t know if you’re saying I should drill through the wings? I like to spread the wings and prefer not to harm them, plus their integrity is often necessary for identification purposes. The right side of the thorax elytron ends up being almost ventral which would make it get pinned sideways/upsidown.

I guess I’m just confused on your terminology. Can you draw a picture of what you mean?

gasman's avatar

I started collecting insects in the 1950s. My first serious book on the subject was How To Know the Insects by H.E. Jaques, recommended by my science teacher who had studied entomology. I still have a copy of it. On page 15, under the section “Pinning the Insect”, various body locations are given for pinning different kinds of insects—many are pinned through the thorax (pronotum or scutellum), usually slightly to the right of the midline. But for beetles the author clearly states: Right front wing (elytron) toward the base.

Are you using insect pins? They are made of spring steel, very sharp, & come in graded sizes. In my experience as a hobbyist, if the specimen has a tough, thick cuticle then try pushing the pin perpendicular to the surface. You can then straighten out the pin once it’s pierced through, before piercing the opposite spot on the bottom (ventral) side.

You can get insect pins from online suppliers such as BioQuip.

gondwanalon's avatar

The word elytra comes from the Greek word “elytr” which means a hood or cover.

When the beetle takes flight, the elytra lift up (like the hood of a car) allowing the membrane wings to extend out and to function.

Beetles have 4 wings: 2 elytra and 2 membrane.

I hope that this helps.

delirium's avatar

@gondwanalon Yeah, trust me, I know all that.

@gasman Yeah, I’m using insect pins.

I’m going to try pinning through the scutellum and see how that works out. Additionally the jewelers drill should help. Maybe.

gondwanalon's avatar

With all the effort and care that you give to your specimens I’m sure that they will look great. Be sure to use moth balls to protect your hard work.

MissAusten's avatar

@delirium Do you have pictures of insects you’ve pinned? Is it your own collection, or something you do for school/work?

delirium's avatar

Thanks All

@MissAusten I’ll eventually take some pics. I may have a few around here. But all the pinning is for me as a hobby.

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