Lepidopteran genital dissection

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lepidopterolog, 09.11.2007 23:24

I hope the topic will be useful for everyone. The proposed method is far from the only one, so everyone can write what method they use. Dedicated to the Ripper
So, let's start with thin nail scissors, the abdomen of the prepared specimen is cut off to half and placed in a test tube. In a test tube, pour a little 10-20 % alkali (preferably KOH) and put it in a saucepan in a water bath. Water must not enter the test tube! Water in a saucepan is brought to a boil, the pan is kept on low heat for 30-40 minutes (depending on the size of the butterfly - the larger the species, the longer). Remove from heat and carefully remove the test tube. Using thin tweezers, we take out the abdomen and put it in a Petri dish with water. Next, you will have to work very hard: you need to carefully remove the genital apparatus from the abdomen, removing all the excess (muscles, ligaments, remnants of the fat body, etc.). This is best done under binoculars or a powerful magnifying glass. As a rule, after cooking, the genitals are easily removed by pressing on the end of the abdomen with a blunt dissecting needle. With the help of two needles, the genitals are cleaned of all excess, taken out of the water and dried on filter paper. Now the genitals can be permanently stored in a drop of glycerol in the cell of a pill blister, which is pricked on a butterfly pin. That's all there is to it
The genitals are straightened directly during viewing, on a slide in a drop of glycerin. It should be added that the lye can be reused quite a few times until it turns brown. When cooking several bellies at the same time, the main thing is not to confuse which genitals correspond to which butterfly. For this purpose, numbered test tubes are used, and a piece of paper with its number is pinned on each pin with a butterfly.
The method only seems cumbersome, but it is completely uncomplicated (I did it the first time).

This post was edited by lepidopterolog - 09.11.2007 23: 38

Comments

12.11.2007 18:22, okoem

Caustic potash is bought at the market, sold in white plastic cans with a hermetically screwed lid.

I was told this technique.
The drug is placed in a test tube with alkali. Next, a piece of gauze, folded several times, is thrown over the throat of the test tube. When boiling, lye can sometimes "shoot", and gauze is needed so that splashes do not fly out of the test tube.
Next, a piece of newspaper is taken, rolled up into a tube, the tube is flattened and thus a dense paper strip about 2 cm wide is obtained from the newspaper. We fold the strip in half, so that this strip bends around/ covers the test tube, the edges of the gauze should fall under the strip, i.e. be pressed down by it, so that the gauze does not fall off the neck of the test tube. Next, we hold the entire structure by the ends of the strip folded together and boil it over a spirit lamp or on gas.
Boil until pure chitin remains in the test tube. After that, we wash and examine it under binoculars or a microscope.
You can preserve the drug in a drop of sugar syrup. Then the drug is put in water and the sugar is dissolved.

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03.12.2007 21:24, NicoSander

Digestion of the abdomen is carried out in a 10-15% solution of caustic potassium (sodium). When cooking in a chemical test tube on an alcohol lamp, in order to avoid throwing out the boiling solution, constant shaking is necessary, which also contributes to the rapid removal of flakes and allows you to notice the readiness of the preparation in a timely manner (transparency of the abdomen). Small preparations usually require processing within 1-2 minutes, large ones-up to 5 minutes or more. It is better, however, not to cook the abdomen until it is completely transparent – the remains of tissues and the fat body can be destroyed with preparation needles under binoculars, preserving the integrity of the abdomen, after which two or three times boiling is enough to enlighten the drug. Sometimes, especially when several preparations are processed simultaneously, digestion is performed in crucibles or buckets on an electric stove, or long-term exposure in a cold alkali solution is used. To avoid the appearance of air bubbles, it is preferable to wash the preparations in boiled water. Consider preparations in pure glycerin; for large butterflies, take a salt shaker or glass with a hole, small preparations are placed in a drop of glycerin on an ordinary slide. The genitals are pulled out of the abdomen with dissecting needles and straightened in the desired angle. In some cases, to maintain the desired position, the drug must be pressed with a piece of cover glass.

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05.12.2007 5:41, Vadim Yakubovich

Good evening! Lye is not ethyl acetate, it is easy to" make " it yourself.
Take ordinary baking soda (NaHCO3), pour a not too thick layer into an iron saucer and warm it up. Lye - fine white powder:

NaHCO3 → NaOH + CO2↑

(!) Coal gas is released. Not so bad, but it's better to open the window.
Ps: ethyl acetate is also not difficult to get, but in my opinion, acetic acid is much more convenient.
I'm glad if I helped anyone

It won't work. At most, Na2CO3 is formed and carbon dioxide is released with water. There is an old method when a solution of sodium/potassium carbonate was boiled with slaked lime. After some time, a sufficiently high concentration of alkali accumulated in the supernatant. By the way, sodium carbonate itself has alkaline properties. Or simply, go to school, to the chemistry room and get ready. The substance is cheap, they will not refuse.