In my experiene pin if big, glue if small, wet if delicate.

I have a private collection of beetles (mainly Buprestidae). I prefer pinned specimens, but small ones (say, below 3-4 mm in width) may be damaged by pin No. 1 or more, while thinner pins are difficult to handle (e.g. to insert in not very soft bedding of insect-box, so I glue them (small specimens) on cardboard triangles (on right side of metasternum) and pin the triangle. I do not like to glue larger beetles because they are then very difficult to handle, ventral side is poorly (if on transparent plastic lamellae) or not at all (if on cards) visible ad must be unglued before examination, what is terribly time-consuming and provokes damaging. Gluing large (even very large) specimens on cards with the "ideology" to have them "perfect" is now popular, but in my opinion it is only good for amateurs (i.e. "amateurs type C" in my terminology: non-scientist fancy collectors) or for expositions, i.e. when the beetles are not expected to be scientifically studied. Of course larvae may be better kept wet in some preservative, but I work only with imagines, so this is not my problem and not my expertize...

Hi there,

while working on psyllids (Hemiptera: Psylloidea) during my PhD, I tried to generate three separate collections, including mounted (glued, since they are very small), microscope slide mounted and ethanol preserved specimens.

I really think it is important to preserve some samples in each of these ways, especially since psyllids (like aphids) are quite small insects with soft bodies. This is mostly due to the fact that none of these preservation method is perfect.

For example, dry mounted specimens tend to shrink and it is very hard to distinguish the genitalia. On the other hand, ethanol preserved specimens are very useful for genetic studies (DNA is preserved) but the colouration could fade with time. Similarly, microscope slides allow a clear view of the morphological characters but do not allow (usually) to keep the specimens intact, instead they require dissection.

Therefore, I know that in many institution, at least in New Zealand and Australia, insects are preserved in all these ways. However I am not aware of policies or guidelines.

Hope this helps!

I strongly suggest, as a complete priority, keeping some or all specimens in absolute (95%) ethanol, or a better molecular preservative. The reason is that in the near future it might become impossible to report or publish on many topics without supporting molecular data. Whether you agree or not with this policy, a great deal of molecular information (genetics of the specimen, its microbiome, etc) is certainly lost with conventional (pins, etc) preservation. Regarding loss of color, it occurs anyway in many insect groups, like grasshoppers, dragonflies, ants, etc. when pinned or stored conventionally (dry), so the best solution might be to take numerous photos before storing specimens in liquid preservatives as mentioned.

Hi all,

in my private collection I have specimens pinned (Orthoptera and Heteroptera Gerromorpha) and specimens glued on cards or card tips (Heteroptera Gerromorpha).

In the collection of Fondazione Museo Civico di Rovereto there are mostly pinned insect, plus some glued and in alcohol specimens. Here we hold the collection Livio Tamanini (Palearctic Heteroptera) and the largest Orthoptera collection in Italy (Galvagni and Fontana Paolo Fontana ).

There is no written policy at the moment in the museum.

Ciao

Filippo

Hi, I keep a personal collection of about 100 boxes, almost exclusively Lepidoptera and Coleoptera. I have all Lepidoptera pinned, and most beetles, except very small ones which I glue on cards. I think pinned specimens are the best, cause you can examine also the underside, but for very small ones (less than 5mm) you can't avoid glue, otherwise very possibly you will damage the specimen trying to pin it, even with number 00 entomological pins (especially if it's beetle). Regarding ethanol, I don't use it at all with Lepidoptera (scales will be washed out). I use it for beetles or anything else, BUT I put them only for a few hours after killing them by freezing. This helps avoiding corruptions like rotten specimens (black corrupted membranes between head-pronotum and pronotum-mesothorax..) during drying. But you can't keep specimens in alcohol for long time..They become brittle..Alcohol (+95%) is good however for keeping the specimens for DNA studies, as known. Regarding larvae, I freeze-dry them slowly (months), but the result is amazing!! They look like alive! Then I glue on cards. As for sensitive insects like Odonata (loss of colour) or Orthoptera (shrinking abdomen, colour loss), I pin them directly after killing, and freeze-dry them. The result is quite good.

17 XII 2018

Sergio: At least as regards the [overwhelming majority of] beetles, traditional pinning (directly of specimens or of cards they are glued on) is so much more convenient and so much better suiting the most cases of scientific (especially morphological) study that it would be a nonsense to preserve them routinely (except from specific projects, e.g. molecular analysis) otherwise. I, for example, as an entomologist, not biochemist, am interested in taxonomy, biogeography, evolution of beetles – entire beetles, not only their DNA sequences! – for me (and other “comprehensive” biologists) colour, shape, size, proportions, details of pubescence or sculpture, &c., &c., &c., which I can more or less exactly interpret in terms of biological function, homology, probable (immediate and evolutionary) reaction to environmental changes, &c., are much more informative (and so much more important) than the difference between AGTGCT and ACTGCA, and examination of all these morphological data can be incomparably more efficiently (quickly, exactly, reliably) done with pinned specimens than with those preserved in fluid (everyday I see my Wife working with – by necessity preserved in formalin or alcohol – small crustaceans, so I have ample opportunity for direct comparison...). Moreover (also very important!) practically all scientific collections of beetles have been preserved as pinned (or glued on cards) specimens, so the eventual “cultural revolution” proposed by you would make any (necessary not only for a taxonomist) comparison with “historical” material (e.g. type-specimens, those collected in no more existent localities, longer series of currently rare taxa, &c.) additionally difficult and less reliable.

Even the molecular analysis can make sense only if the specimens are reliably identified, and identification keys are – and in the predictable future will be – based on morphology (as to the role of “DNA-barcodes” see the attached paper), the more so that for many species (e.g. fossil, recently extinct, very rare, inhabiting areas unaccessible for collectors, &c.) DNA sequences will probably never be known. You are right, there is nowadays the tendency to “exterminate” morphology and morphology-based taxonomic publications from the self-styled “top”-journals (highly censored, profit-oriented editions of Elsevier, Brill & Co.), but there always remains the possibility to publish in Procrustomachia or similar journals, and if the incresingly dominating oligopolists succeed (I hope they will not, but in this New Brave World anything is possible...) in their efforts to prohibit uncensored editions, then scientific activity would lose any true sense, and those who wished to honestly contribute to the real knowledge of the real world rather than practising “a kind of academic prostitution” would need to change their profession whatsoever; in such situation the way of preservation of insect specimens would be totally immaterial... But fashions come and go, so I hope the fascination in reducing a living organism to a sequence of four capital letters will also pass over!

So, to conclude: as regards beetles, “wet” preservation should be applied only to previously reliably identified individuals predestinated to some special study (like DNA-sequence analysis), whereas the “general purpose” collections should be kept as dry, preferably pinned specimens!

I agree with Roman. DNA is just another tool. It's not everything. It should be used in combination with classic morphological studies, which I find more important. If we accept any result of DNA studies (in many cases they are strange..), doing taxonomic revisions basically according to them, then we could have a taxonomy less close to reality..So, collections of pinned/glued specimens are very very important.

Hmm.. there was a survey on facebook by Mike Ferro on this topic recently. I'll forward it to you.

I have a collection of staphylinid beetles. Since most of these are tiny I glue them. I pin only very large specimens and these only rarely because in my opinion once you pin them some structure is destroyed irreversibly. And if in case of a revision you want to do genital preparations later (you nearly always have to with Staphylinidae), then you would have to take animals off the needle and on again, which is not a good idea.

I only glue only one or a few animals of a species series and keep the rest in ethanol since they might be useful for DNA analysis somewhen in future. Sometimes I send such intentified specimens to DNA banks like BoLD.

But a word here: Preparation starts already before collection management. If curators are actively collecting animals for their museum collection, they should avoid formalin in pitfall or other traps, since later analysis of the DNA will then not be possible anymore.

I have a collection of Cerambycidae. Most of my specimens are glued except the big species (for example Prioniinae); these are pinned.

I do normally take good quality pictures, dorsal, ventral and laterally, so I can study any details without needed to "disturb" the specimen.

If for any reason I need to de-glued some specimen, a few drops of ethyl acetate over the glue will dilute it very fast without any damage for the specimen.

I strongly believe this system avoid the damage of the specimens and avoid the frustrating situation to see a lot of Types with legs and antennae broken and lossed after some years because of the study/handled by different scientifics.

@Sergio: As for the type of glue I can recommend simple wallpaper paste. Just a drop of water is needed to detach the animal from the platelet. It only takes a minute or so to liquefy this type of glue. And if you leave the (tiny) animal in the drop for half an hour or so, eventually renewing the drop, then the beetle might be even soft enough to do genital preparations right on the platelet.

Thanks Armin for your advise.

I do normally use a white glue for wood, paper and so on, used by the students for mannual works and diluted in water.

I will test your wallpaper

In our laboratory, we keep specimens as dry pinned, glued and also in absolute Ethanol. In my opinion specimens also be kept directly in -80 degree refrigerator without using ethanol or any other fixative. It could be useful for examining characters which are delicate. In my laboratory we have specimens of Elateridae, Meloidae, Coccinellidae, Buprestidae and other insect and arthropod specimens.

About alcohol and genitalia: alcohol tends to spread the specimens' intersegmental membranes. Sometimes this happens to such degree that genitalia come fully out of the abdomen. I have experienced this especially with some Tenebrionids, after putting them for some hours in alcohol after killing.

So, at least for some fresh specimens, alcohol can be helpful with genitalia (avoidance of destructive preparations). On the other hand, in addition to the disadvantage of making specimens brittle, alcohol often makes them oily, as dissolves the fat, and then they need gazoline baths.

At least all pre-imaginal stages (larvae, nymphs, pupae) of all insects, and all stages of all apterygote insects, Ephemeroptera, Plecoptera, Copeognatha, Parasita, Thysanoptera, Plantisuga, Trichoptera must be kept only in liquid (90% alcohol is preferrable). For some other taxa dry collections are still used, and because of this systematics of these taxa remains to be on a rather low level.

This is off topic of my discussion's question.

Hello Dmitry;

I tend to a teaching collection of about 100 drawers and about 10 m of wet shelves The wet specimens are stored in 95% EtOH. The vast majority of the collection is pinned because it is far more useful in the teaching lab and is very much less expensive to maintain.

1. Those small specimens (mostly parasitic wasps and ants) that are glued to points are the subject of concern about the adhesives used to attach them. "Hide glue" is what is in current use but we are experimenting with some polymers that are reported to have greater longevity.

2. There are no written departmental policies concerning these practices. Students are trained by the faculty whose practices are fairly uniform.

I look forward to your summary comments, Jim Des Lauriers

I am working on chalcidoids(Micro Hymenoptera), I used to sort specimens in 80% Ethanol and thereafter mount them on rectangular cards using glue.

To pin is best. But occasionally glue for very tiny insects.

Dear Dmitry;

Large (> 1cm) and hard-body insects are pinned. Small hard-body insects are double-mounted and glued on their sides on a triangular cardboard . Small soft-bodied insects like hymenopteran parasitoids are preserved in 70% alcohol

To everybody;

Several of the earlier comments about the adhesives used in putting insects on points or cardboard indicate how diverse the adhesive choices are. Some of them are not durable. This is quite a problem in collections where the specimens are intended to be long-lasting. Here is a link to a paper that evaluates the problem and some of the alternatives.

Preprint A review of adhesives for entomotaxy

Regards, Jim Des Lauriers

1. All of the above, depending upon taxon/size.

2. No, as I'm an individual.

3. For Formicidae, always point mounting using liquid hide glue. Almost everything else (mainly Coleoptera, Hemiptera, Diptera and other Hymenoptera) is either pinned (micro in a plastazote strip and pinned) or pointed depending upon size. I never card specimens. Unmounted ants from a nest series and anything soft bodied is retained in 94% ethanol.

4. Mostly I want a reference collection with key features visible, which dictates the choice of mounting technique. Ants in ethanol are occasionally provided to researchers undertaking genetic work.

Yes, depend on taxon or on what you want to see at it. For gluing, it's a must to use a 100% water soluble glue. never know when you need exactly the glued part of the insect to identify or re-identify it.

I work on Syrphidae and always dry pin my specimens. The pin is put through the thorax at the right side as many species have latero-medial pollinosity or some kind of symmetric colour pattern.

I have a private collection so no policy on paper.

I have studied many collections and found glued specimens too. They tend to go loose easilly, especially when trying to soften them in some kind of humidity box. The wing and legs tend to be glued to the cardboard too and characters get obscured rather easy. So in Syrphidae I do not advise glueing.

Preserving wet (alcohol!) is only for short period and to extract DNA. If kept in alcohol for prolonged periods colours, pollinosity and even pile tend to get blurred and identification gets more difficult.

the pin is best because im interesting with buprestids beetles and I had a private collection so no policy needed.

hope to read more a bout this subjects with my respect

Dmitry Telnov it depends of the order :

- Dermaptera are glued (because pinning damage them, as the body is usually elongated and quite soft, it often breaks when pinned) but Thelyphonida, Embioptera and Mantispids are kept in alcohol. I try to keep some Dermaptera in alcohol too, to enable DNA studies

- it's my own private collection so no policy. Purpose of it is systematics and phylogeny researches

Hello Dmitry: I happened upon a paper that is pertinent to your question. The title...A review of adhesives for entomotaxy. doi.org/10.7287/peerj.preprints.27184v1

The permanence and reversibility of various adhesives in common use are evaluated. It might be useful to several of the people who have commented here. best regards, Jim Des Lauriers

Hello Dmitry:

1. Yes in our Museum we pin the specimens (large specimens like Coleoptera, Hymeopotera, Lepidoptera, Odonata, Hemiptera etc.). Small insects like parasitic hymenoptera (Chalcidoidea, Braconidae, Ichneumonidae etc), ants (Formicidae), small coleoptera and Hemiptera we glue on triangular cards or points. We try to avoid alcohol, only temporaly or kep them for longer periods for DNA extractions.

2. Yes, we have in our institution a guideline regarding mounting of entomological specimens.

3. I work all orders, specially Lepidoptera, Coleoptera, Hymenoptera, Hemiptera, Odonata, Mantodea.

4. For soft body insects like mealybugs, thrips, aphids, spidermites, scaleinsects, whiteflies, we mount them in microscope slides protected with a glass cover glued with Canada balsama. Prior to slide mounting the specimens are cleared in 10 % KOH and then stained with acid fuchsin ( only for mealybugs, whiteflies, spidermites, thrips, aphids, genitalias of Lepidoptera, Hymenoptera and Coleoptera).

Of the three methods pinning is more suited but in allthree practices of preservation insects original body colour will be lost.At least one type specimen can be stored in deep freez to retain all physical features intact..

In my experiene pin if big, glue if small, wet if delicate.

We pin fresh specimens as well as preserve in solutions depending

I work with leafhoppers and planthoppers, usually preserved in 70% ethanol (99% if molecular analyses are needed)

The pin is put through the thorax at the right side

Pinning: Every dry specimen will be mounted on a black insect pin. These pins come in a variety of sizes and the size of the specimen will dictate the size of pin. Different types of specimens also require diffrent pinning techniques. Most insects will be pinned through the thorax on one side (usually the right) of the center line.

Glue: A point is a small triangular piece of paper that is used to mount small insects (thrips, lice, aphids etc.). A dab of Elmer's glue is placed on a piece of paper and then dried until tacky (a minute or two). It is an excellent way to preserve and study small soft-bodied insects. The specimens are placed on the left-hand side of a microscope slide and a drop of mounting media (Canada balsam) is added. Then a cover-slip is placed over the media and specimen.

Wet: This method is used for softer insects (larve and the like). The aquatic insects are preserved in containers in 70% ethanol.

Cada metodología tiene sus pro y sus contra, la coleccion seca (Pegamento y fijacion) son mas economicos, mientras que la coleccion humeda, tiene mayor manipulacion con el paso de tiempo, ademas que facilitan la extraccion de ADN.

One more important remark: in the last years there is a spreading custom to glue even large or very large beetles on cards. This is usually "justified" by arguments of aesthetical or "curatorial" [allegedly better protection against accidental damage of legs and antennae] nature. In my opinion, both allegations are flawed, but even if true, this must not be the decisive factor: well, to frame the beetle in a more or less elegant glazed casket and hang it in the wall like a keepsake photo it may be pinned, glued, embedded in plexiglas, or whatever you wish, but killing animals for such goals is anyway hardly acceptable, in fact barbarian custom: the main - in fact: the only valid! - justification of collecting living organisms is their scientific/educational function, and serious scientific study of collected specimens is unconceivable without the possibility to examine not only their dorsal but also (in many groups much more important!) ventral side! Accurate examination of ventral side is evidently impossible on a glued specimen, so it must be unglued what - besides creating a real danger of damage and (still worse!) confusion - is a time-consuming procedure, making scientific study unacceptably lengthy and/or inexact! So,

1) collected specimens should be easily available for exact scientific study; therefore

2) beetles (and representatives of other hardly chitinized groups, like bugs) should be pinned or, if too small for pinning, glued on triangles from side, whereas

3) gluing on cards so that ventral side is not visible should be avoided anyway, and never done with specimens of more than 3-4 mm. in width;

4) if gluing (e.g. of very small or seriously damaged specimens) is nevertheless unavoidable, use always a water-soluble glue - using of "waterproof" (e.g. aceton-based) glue for biological specimens is simply a crime!

Wishing you effective studies!

Roman

I have a small personal collection. I pin most insects using a #3 insect pin. I glue them to points if the insect is too small for this treatment. Immatures are preserved wet. I have a few ants where I collected several dozen individuals from a single nest. These are preserved wet to keep the different casts together.

An instructor disliked the fine insect pins because they have a tendency to flick their specimen across the room if you do not remove the pin from the pinning box perfectly straight.

In my youth I liked Riker mounts. I abandoned that once I started identifying specimens. All of the Riker mounted material worth keeping is now pinned.

I agree with Bert Kohlmann .

Hello Dmitry.

I only have a private collection and, in my case:

1. the preparation depends on the tipe of insects/animal and what I pretend with them. Some are in pin (Lepidoptera), other glued on cards (ants or small species like little Coleoptera), others are keeped wet with al least 70% alcohol (spiders, mealybugs, aphids, larvaes, caterpillars and other animals like small reptiles) and even others just dry (Coleoptera, Orthroptera...some caterpillars and pupae). I also have some Odonata dried and others in pin, all depends on the purpose. Being a private collection...I basicly can do whatever I want.

2. The preparation method that I use is the way I learned in Entomology. For pinning I use entomological pins and follow the rules, i.e. Coleoptera - Pinpoint in elytron on inner front of mesothorax (glued on card, in triangule, when they are too small), Lepidoptera and Orthroptera correctly pinned with none, one or two open wings; etc.

3. All that I find, like and prepare.

4. Since child that I always liked to observe, capture and learn with the insects, spiders and animals in general. Having a bedroom full of dead insects was always normal. Without a correct order, I allways had my collection. While I was growing up I became aware of the methods of preparation and during my studies, I actualy learned how to do it correctly and started to use it. The purpose of my collection is for my joy, for learn and to be able to show and demystify to others this "little world" of life.

as I am working on Moth (Lepidoptera) specially on Erebidae. ya, I am pinning the specimens with ento pins as according to their size. Mounting on glass slide only their external genitalia earlier in my lab. but, now a day I am using Leica microscopy for photography and same genitalia kept with me for future references.. mounting of specimens not done in my lab. preservation dry wooden box collection chambers recommended.