Preparation of genitals

Community and Forum → Entomological collections → Preparation of genitals

24.10.2016 15:46, AVA

I have been using this method for a long time, only now there is a heat-shrinkable tube (cambrick), sold in radio markets and radio stores, I take transparent, different diameters for different sizes from 2 mm to 5 mm. First, one end is sealed, a gas lighter, Then squeezed with tweezers, a drop of glycerin is added to the bottom with a syringe, the preparation is added to it, if necessary, glycerin is added, the absence of glycene is required 2-3 mm from the open cut, It is heated, the cut is squeezed with tweezers. Germitichnost is checked by easy squeezing.

I have been using similar polyethylene tubes of different diameters for many years. However, with one difference. I do not clamp the outer end of the tube, but insert a plug made of styrofoam "worms" cut into pieces, used as a sealing filler. This ensures constant access to the drug without the need to cut off the outer end of the tube (and, accordingly, shorten it).
When necessary, without removing the container from the pin, I remove the stopper and take out the drug with a curved pin at the end. No problem.
There are only a couple of important points. First, you need to heat the tip of the tube, but clamp it with cold (!) tweezers. Secondly, glycerin should not reach the plug from the inside, so that there is no capillary leakage.
By the way, some foreign analogues also suggest the possibility of regular opening of the container. But their difference lies in the fact that the pin is stuck not in the flattened "tail" of the container, but in its silicone plug. However, it is more difficult to remove such a container from the stopper than to remove the stopper. And, as experience shows, " my " way is simply safer for an impaled insect.

24.10.2016 17:09, EvgenD

For storing drugs, I use tubes from droppers, it is sold in almost any pharmacy, it is inexpensive, the kit includes about a meter of the tube. The exact name is "one-time system for infusion of infusion solutions", the pharmacists themselves call it simply - "system". For small and medium-sized butterflies, it is quite suitable, larger scoops, for example, Amphipyra pyramidea, are already problematic to cram there (therefore, in addition, I recently purchased a package of micro-tubes "for a large animal" on Entosfinx). I borrowed the idea here, on the forum, about 5 years ago. But the tubes were supposed to be sealed at both ends. Pretty quickly, I decided that this was inconvenient and began to solder only on one side, and on the other - to plug a small plasticine stopper. Now I first solder and cut the tube into pieces of the desired length, then use a syringe to inject 1-2 drops of glycerol into each piece (insulin syringes are not suitable, the hole is too small, the glycerol does not pass well; you need to take a syringe with a thicker needle). then I make plugs and plug the "test tubes". After that, I glue a rectangle of cardboard to the middle of the tube with cyanoacrylate glue (supermoment), for which the entire structure is pinned under the insect. It looks something like this:
picture: IMG_7742.jpg

25.10.2016 21:51, EvgenD

"...these tubes are made of PVC ..."

I hadn't really thought about it before. Can you tell me how to determine what plastic the tube is made of? I didn't find any labels on the packaging about this. As for the difficulty of sealing, the photo is rather not a very successful sample, which was made in a hurry. If you carefully heat the tube near a low flame (for example, an alcohol lamp or a candle), it melts normally and does not burn, a flat tail is easily formed with tweezers.
The question of the reliability of gluing also bothered me, I used other adhesives before. Sometimes the tubes fell off. I have been using cyanoacrylate for 3 years, during this time there were no problems. Perhaps gluing is really worth giving up. Next time I'll try to make longer ponytails and pin the tubes through them.
My plasticine plugs do not claim to be leak-proof. They may lose their properties over time. I'll be able to tell you about it in 20 years. One colleague suggested using wax instead of plasticine, but I haven't had time to try it yet. Probably, it is possible to plug both sides with plasticine, why not. I just do what I'm used to. I also saw the option of storing drugs in such tubes, sealed on one side and open on the other. But in this case, the glycerin will dry faster.

26.10.2016 16:12, AVA

I hadn't really thought about it before. Can you tell me how to determine what plastic the tube is made of?
PE melts under moderate heating. PVC-as if it swells, and then charred and burns with the release of black smoke and an acrid smell. Silicone does not melt at all, only deforms.

... the photo is rather not a very successful sample, which was made in a hurry. If you carefully heat the tube near a low flame (for example, an alcohol lamp or a candle), it melts normally and does not burn, a flat tail is easily formed with tweezers.
In principle, you can create a "tail"for their PVC pipe. But the compressed layers do not fuse, as a result of which glycerin flows through the remaining micro-gap, causing corrosion of the pin.

The question of the reliability of gluing also bothered me, I used other adhesives before. Sometimes the tubes fell off. I have been using cyanoacrylate for 3 years, during this time there were no problems. Perhaps gluing is really worth giving up.
For gluing PVC, there are special types of glue that I haven't seen on sale for a long time. And since I myself did not use such glue, I have no idea about its durability. But the fact that such glue, judging by the smell, contains vinegar, is not good for collections.

My plasticine plugs do not claim to be leak-proof. They may lose their properties over time. I'll be able to tell you about it in 20 years. One colleague suggested using wax instead of plasticine, but I haven't had time to try it yet. Probably, it is possible to plug both sides with plasticine, why not.
Plasticine has one hidden disadvantage – often its plasticity is based on the addition of glycerol to the original mixture. So when glycerin gets on the cork from the tube, plasticine absorbs it and turns into sour cream, thoroughly soiling the tube itself from the inside. Neither wax nor paraffin improves the problem.
I tried a different approach: using a metal tube of the desired diameter with a sharpened edge, I simply cut out cylinders from fine-pored PPE ("foam"), with which I plugged the tube.

I also saw the option of storing drugs in such tubes, sealed on one side and open on the other. But in this case, the glycerin will dry faster.
Yes, it will gradually evaporate if the humidity is low. But, on the contrary, at high humidity, glycerin absorbs moisture, filling the entire tube and even flowing out of it.

26.10.2016 17:50, AVA

Long been sold here are such figoviny very convenient.

These are the test tubes I had in mind when I mentioned foreign analogues (see URL #378).
But I would not be in a hurry to say that they are more convenient than others. Tested by experience and denied use. Why?
First, I have already written about the fact that the test tube is removed from the silicone stopper with difficulty.
Secondly, it is even more difficult to return the removed test tube to its place. You must first insert a thin pin between the stopper and the tube wall, push the tube all the way down, and then carefully remove the pin. The fact is that the silicone stopper fits very tightly into the test tube, and the compressed air simply pushes the stopper back (perhaps someone else remembers how the rubber stoppers on penicillin bubbles were closed?). In this, in principle, there is no problem when you have pin number 3 and thicker, and when 00-000? Yes, with your manipulations, you are more likely to bend the pin or damage the object than to remove the test tube and return it back.
And, finally, you have a cute bug removed there. But my objects are at least 3-5 times smaller than even the smallest of the available test tubes of this type. Do I have to fill the whole box with test tubes?
No, please don't.

Likes: 1

26.10.2016 20:01, Bianor

Some are spinning, so you have to clamp them not in the bend, but near the test tube. You can't even stick a zero in most of them. Here's a little thing with test tubes, nothing is spinning:

user posted image

By the way, about the size. Here are the genitals of Inurois and some moth on the same scale, which I cooked just for the sake of example:

user posted image

The butterfly itself is twenty times larger, and the genitals are so tiny that you don't even have to combine pieces of images, it fits completely into the frame, and there is still room. Most likely it is connected with the winglessness of females, because Erannis also has disproportionately small genitals, but there the butterfly itself is large.

This post was edited by Bianor - 26.10.2016 20: 13

Likes: 2