If you can't find one, try drying the elytra and then mark them using a fine, permanent (alcohol soluble) line pen

Hi Randolph

Have you tried one of the printable labels from

http://www.cils-international.com/content/cils-laboratory-laser-printable-durable-labels

they seem to have a wide variety of types and some can be immersed in solvents or water and can tolerate a wide range of other conditions.

Hi Randolph,

we have some fairly mixed experience using permanent (oil) paint markers and superglue+"plastic" paper that does not extend when wet (using the method described in Davy-Bowker 2002 paper). I will be happy to share experience and tips with you. Neither of the two methods worked flawlessly for us and I am looking for an improvement as well.

Edit: I think your Papilio link might be similar to the stuff we used (except that it was not provided with the adhesive layer) but I cannot say for sure. The main problem is to come up with tags that stick to the beasts long enough, many are surprisingly good at getting rid of things...

I have no experience attaching labels to insect cuticle, but you might try some of Diversified Biotech's Tough-Tags printable labels. Some are solvent and water bath resistant polyolefin labels designed for adhesion to plastic, glass and metals. http://divbio.com/tough-tagslaserlabels.aspx

I have no experience, but you might be try nail polish. I use it for marking flour beetles.

Thanks all for the responses. We have been using nail polish, but need individual marks for hundreds of beetles, hence the printable numbers on labels. I have written to both companies suggested above, and only divbio got back to me. They don't know if their best will be good enough, but they're sending me a sample to try, and I'll report back to them.

Randy

HI Randolph, look at this paper around marking of ground beetles "A method for rapidly mass laser-marking individually coded ground beetles (Coleoptera: Carabidae) in the field". That group used a laser to permanently etch a number into the elytra of the beetles making each one distinctly identifiable and permanently marked avoiding any potential for loss of ID.

I have used plastic labels made with a machine like the DYMO® Express Pro™ Handheld Embosser affixed with super glue to mark crabs.These can be trimed to a relatively small size and the combination of numbers/letters and tape colors allows for a large number of unique labels. These were permanent until the animal molted.

I have used Hallprint shellfish tags and superglue to attach to freshwater bivalves. They are very thin (and flexible) vinyl labels but you do need to use glue for them. They can print whatever coding you want on them, check the website here http://www.hallprint.com/1327/1390.html.

3M manufactures a veterinary surgical form of cyanoacrylate glue called VetBond. It sets on contact with water and on larger aquatic animals will keep a label attached for at least a year. There is a small amount of heat released on setting, so quick immersion after placing the label is probably a good idea.

Randolph, did you find suitable labels? I'm looking for a solution for permanent tags for largish (>1cm) diving beetles and would be interested in your experience.

Try Museum Supplies, e.g. http://www.supaprice.co.uk/p/result.jsp?q=waterproof+paper&qs=ti&ts=go for waterproof paper - you would then have to glue it on.

I have used a dot method based on Earlich and Davidson (http://images.peabody.yale.edu/lepsoc/jls/1960s/1960/1960-14(4)227-Ehrlich.pdf) with some success on Bloody nosed beetles

Hi , you may be interested in this paper: A new approach to individual marking of insects: usability confirmed in semiaquatic bugs Vojirova and Ditrich.

To Dave and Alessandro: permanent submersion in water is the source of all the trouble... (BTW, Tomas Ditrich is my colleague - they used a method similar to what we did with diving beetles but their bugs do not dive :)

To Randolph: I would also be happy to know what solution you found to be working best for you in the meantime, especially for beasts with smooth elytra, such as Graphoderus or male Acilius.