Sooner or later, every coleopterist will need to consider the moral issues surrounding ‘collecting’. ‘Collecting’ in the sense used by entomologists is almost always a euphemism for ‘killing’. Few specimens are found already dead and although one might think you could ‘collect’ a specimen, study it in life and then release it again, this is not common practice.
It is possible for a beginner to make serious progress in the study of beetles without collecting, but this is a difficult route which few have tried. The literature frequently assumes beginners will collect, and often fails to mention that it is ever possible to identify beetles without collecting them and keying them out. Those who do choose to collect specimens will doubtless wish to limit the number they take and to minimise any negative impacts they may have on populations.
- To generate reliably-identified records – these can be fed into the national recording schemes, or to Local Records Centres and be used to the benefit of conservation. Records based on specimens can also be re-identified in future if additional species are recognised as British.
- To develop your own reference collection – this can then be used to develop your identification skills to the point where you can identify more beetles in the field, and begin to study behaviour, habitat use and other aspects of their ecology and natural history.
- To promote the study of beetles to others, who may have very limited experience of seeing beetles in the field.
- To study them under a microscope, or to make a dissection.
Bad reasons for collecting beetles
- To fill a collection the way a stamp collector fills a stamp album.
- For profit from sale or exchange of specimens.
Collecting as a threat
The collection of specimens is a necessary requirement of many studies on beetles. Whilst the removal of adult specimens from a population is theoretically damaging, its impact is generally likely to be trivial for the species. Many species occur at moderate to high densities within their preferred habitats, and most techniques for finding or trapping beetles are very inefficient. However, in a few cases, detailed below, collecting can be an immediate and significant threat. It is certain that habitat loss and habitat degradation are ultimately very much more serious threats to beetle conservation. And ignorance of the species, their distribution and their habitat requirements is a serious obstacle to their conservation.
Under special circumstances, collecting can be a significant threat: when a species is easily found, occurs in small populations of long-lived adults, has low reproductive rate, occurs in easily damaged habitat, is targeted by beetle ‘twitchers’, or is targeted by greedy or commercial collectors.
The impacts of collecting can be mitigated to some extent by avoiding collecting gravid females (with conspicuously swollen abdomens) and by preferentially collecting males.
The future of collecting
It is interesting to speculate whether the study of beetles will evolve in the way that birdwatching and butterfly-watching have evolved. In those groups, the collecting of specimens has become increasingly outdated and unnecessary as field guides, field identification skills and optical equipment have all improved. This has also opened the way for a much greater number of people to get into those groups. Could certain families of beetles such as the longhorns (Cerambycidae), ladybirds (Coccinellidae) and ground beetles (Carabidae) go the same way?
How to kill a specimen
If you’re interested in this topic, you should definitely read the comments at the bottom of the page too with some excellent contributions from people with much more experience than me of methods 2, 3 and 5.
1. The best method: ethyl acetate.
Place your specimen in a glass tube, with a tight-fitting stopper. Put one or two drops of ethyl acetate (modern name: ethyl ethanoate) onto a piece of tissue paper, put that into the tube with the beetle and seal the lid. The beetle will be ‘put to sleep’ fairly quickly. Although there may be a period of rigor mortis, this will last no more than 4 – 6 hours, after which the specimen will be relaxed, allowing ‘carding’ (setting in position and gluing to a piece of card). Note that the tube must be glass – ethyl acetate dissolves many plastics! Appropriate care needs to be taken in handling this chemical: ethyl acetate liquid and vapour is flammable. Specimens in tubes with a bit of ethyl acetate will be preserved in a suitably relaxed state for several days, possibly weeks, depending on how good a seal the tube has. They will keep longer in a fridge or freezer.
A good tip from Andreas Herrmann which I’d not heard before is to add a drop of water (or spittle!) to the tube along with the ethyl acetate (1 drop water to 3-5 drops ethyl acetate gives best results). The water enables the hydrolysis of ethyl acetate, resulting in acetic acid and alcohol. Most likely the acetic acid protects the beetles from becoming stiff.
2. A useful back-up in the absence of ethyl acetate: boiling
Dropping specimens into boiling water is an effective and quick way to kill them within seconds, and then quickly transfer to cold water. This also helps to clean specimens. Haven’t tried this. It might even be a better method than ethyl acetate.
3. Alternative method: alcohol.
Submerge in 70% ethanol (alcohol) or IMS (Industrial Methylated Spirits). Beetles killed in this way are quite stiff and very difficult to card, seemingly because the alcohol dehydrates the specimen. They will however remain preserved almost indefinitely as long as the alcohol does not dry out. 70% alcohol is flammable, so care needs to be taken.
4. Alternative method: the freezer.
As with alcohol, this doubles as a killing method, and a method for long-term preservation. Specimens killed in this way tend to be quite stiff.
5. The traditional old method: the laurel bottle.
Young laurel leaves, collected in late May or early June, and mashed into the bottom of a big jar provide a cyanide killing bottle to last a whole year, apparently. Old leaves, and leaves which are not chopped finely enough, are much less effective. Laurel bottles apparently work extremely well, if you get it right.