I suppose you need to observe the chaetotaxy of very small butterfly larvae for identification purposes and for drawing or taking photos. I think that a real dissection of the larva is not strictly necessary. In my opinion, an observation of the chaetotaxy under the stereomicroscope on freshly-dead larvae immersed in gliceryn is sometimes sufficient. But you can also make microscopic preparations on slides, clearing previously the entire larva by treating it in KOH solution (approx. 10% solution, the necessary time depending on the dimensions and sclerification level of the larva, and on the temperature of the solution) and then in distilled water to make the elimination of internal contents easier; so you obtain to preserve only the exoskeleton (cuticular structures) of the larva with its chaetotaxy. In order to facilitate the action of KOH on the internal organs and tissues of the larva, you can previously perforate delicately its cuticle with the tip of micro-pins (e.g. pins used for preparing adult microlepidopterans) in some areas of the integument free from hairs, to avoid damage to the chaetotaxis. After KOH solution, you can gradually ''empty' the larva immersed in distilled water (or in glycerin) by pressing it delicately, using the head of an insect pin. Finally, you can mount the larva on a slide by using e.g. Faure's fluid. Generally in such a way you obtain a dorsal vision of the chaetotaxy of the larva flattened dorsoventrally under the covering slide, but if you have more specimens you can try to prepare some of them also in lateral and ventral vision. Otherwise, when you have cleared the cuticle in the way above, you can simply immerse it into glycerin for a three-dimensional observation under stereomicroscope.  The clearing effectiveness of KOH is sometimes greater on dry specimens than on freshly-dead specimens (it is surely less effective also on specimens fixed and preserved in alcohol).

Best regards,

Rinaldo Nicoli

Thank you very much for your kind reply Sir. Actually I have preserved the first instars in the solution of Alcohol and glycerin. and I have a few collection of larvae and dissections of that also a very difficult  part. So, Is it possible to take pictures and make setal maps by using this. Would photography show the proper arrangement of the setae? Please reply. Thank you.

The procedure described by Mr Aldini is quite simple and effective. I've used it many times. Use "fresh" or preserved in alcohol larvae, make good photos of dorsal side and both laterals, and after this dissolve larvae in KOH to look at the setae of ventral side and on the prolegs. Dissected and cleared in KOH larvae are very transparent, and setae of both sides are visible (it's not very good). And keep in mind, that almost all those beautiful pictures of chaetotaxy are not photos, but drawings, results of observation and deduction, and are sometimes based on several specimens. 

Best regards,

Marek

What is the aim of your research? Simply identification of a taxon by using keys based on chaetotaxy? Publication of original research of morphological or taxonomical value, showing characteristics of the chaetotaxy in larval instars of one or more species? I think you can try to take photos at the stereomicroscope (by using a digital camera and a  computer program useful for a good representation of three-dimensional structures) for seeing if decent results can be obtained in order to your purpose. These photos can be useful at least for drawing a map of the arrangement of the setae on the surface of the different segments of the larval body. Otherwise, you can draw the arrangement of the setae directly by means of a 'camera lucida' applied on the stereomicroscope. If by any chance you have the availability of an electron microscopy lab, you can prepare specimens of your larvae for observing them and taking photos of the chaetotaxy by means of a scanning electron microscope. In this way you are surely able to obtain good pictures of the chaetotaxy.  

Regards,

Rinaldo Nicoli

Some time ago I drew sections of the microsculpture of Phyllonorycter [Lep. Gracillariidae] larvae using a drawing tube attached to a microscope.  This was quite tedious, as irregularities in the surface required frequent refocusing to see the setae clearly.  With more modern techniques I am sure photography would be more effective here.  The larvae were placed directly onto a permanent slides, and mounted in Polyvinyl Lactophenol for viewing.  the setae were drawn by pencil, and then copied onto drafting film with permanent ink.  The figures were subsequently photocopied and stored.  For identification purposes I drew the dorsal setal patterns on the head-capsule, T1, A1, A2 and the anal plate,  I recorded the lengths of the major setae, and where relevant, also their basal widths and shapes.  The pattern of microsculpture distribution was generally useful for characterising the species.   Use of  alcohol for larval storage were unsatisfactory in this procedure.

Regards,

Ken Bond

Thank you very much Sir (Ronaldo Nicoli Aldini).  Actually I have to do chaetotaxy for both identification and  publication purpose. 

Also Thank you  to both Marek Michalski and Ken Bond Sir, for your valuable information. 

With colourless collembola, we use lactic acid (chloral lactophénol is toxic nox), and we analyse chaetotaxy with a Contrast phase mikroscope.

I suppose you need to observe the chaetotaxy of very small butterfly larvae for identification purposes and for drawing or taking photos. I think that a real dissection of the larva is not strictly necessary. In my opinion, an observation of the chaetotaxy under the stereomicroscope on freshly-dead larvae immersed in gliceryn is sometimes sufficient. But you can also make microscopic preparations on slides, clearing previously the entire larva by treating it in KOH solution (approx. 10% solution, the necessary time depending on the dimensions and sclerification level of the larva, and on the temperature of the solution) and then in distilled water to make the elimination of internal contents easier; so you obtain to preserve only the exoskeleton (cuticular structures) of the larva with its chaetotaxy. In order to facilitate the action of KOH on the internal organs and tissues of the larva, you can previously perforate delicately its cuticle with the tip of micro-pins (e.g. pins used for preparing adult microlepidopterans) in some areas of the integument free from hairs, to avoid damage to the chaetotaxis. After KOH solution, you can gradually ''empty' the larva immersed in distilled water (or in glycerin) by pressing it delicately, using the head of an insect pin. Finally, you can mount the larva on a slide by using e.g. Faure's fluid. Generally in such a way you obtain a dorsal vision of the chaetotaxy of the larva flattened dorsoventrally under the covering slide, but if you have more specimens you can try to prepare some of them also in lateral and ventral vision. Otherwise, when you have cleared the cuticle in the way above, you can simply immerse it into glycerin for a three-dimensional observation under stereomicroscope.  The clearing effectiveness of KOH is sometimes greater on dry specimens than on freshly-dead specimens (it is surely less effective also on specimens fixed and preserved in alcohol).

Best regards,

What is the best method of doing chaetotaxy? What type of tools we can use for this? - ResearchGate. Available from: https://www.researchgate.net/post/What_is_the_best_method_of_doing_chaetotaxy_What_type_of_tools_we_can_use_for_this [accessed Sep 17, 2015].

I am very surprised to read a simple copy (duplicate) of my first answer (written 1 day ago to this question asked by Saveena Bogtapa) added (5 hours ago) as an original answer by Khalid Rasib. I hope that this inconvenience was only an unintentional error. Otherwise, I think that a polite way to endorse an answer written by another researcher is to upvote his answer, or to write an answer for agreeing with him (or to do both things). I think (and I hope) that all people of Research Gate will agree with me on this matter.

Best regards,

Rinaldo Nicoli

Respected Sir,

                        Thank you to all for your kind suggestions. Your valuable information has helped me alot in my  chaetotaxy work.  Thank you again.