Comments on curation: Materials for pinning Coleoptera.

Curation, as considered here, the pinning, labeling and storing of insect specimens, is an art, a virtuosity. In my humble opinion, a dying art. Curation, like a lot of things we attempt, is a skill one can only improve by doing. Of course, one must first be able to discern what a well curated specimen is.

In prior posts, I emphasized the importance of accurate, concise specimen data. Whether you collect for the science, the desire to discover new species and add to the knowledge of distributions, biology, and taxonomy, or, you collect for the aesthetics, the intrinsic beauty of a drawer or schmitt box of tiger beetles or butterflies, without reliable data the specimens are scientifically worthless. As they say, it depends on which side of the fence you’re on. Most of us are aware of and avoid those collectors who intentionally provide vague cryptic data with their specimens in an attempt to protect collecting sites from other potential collectors, for monetary gain, or merely to boast they have the largest series of a particular species. 

Since my collecting efforts are primarily for coleoptera, here, and in following posts, I discuss how to properly pin (colloquially referred to as “mount”) those types of specimens. For other insect orders, Orthoptera, Lepidoptera or Odonata for example, the reader should explore the internet for relevant websites explaining the pinning conventions for those specimens.

A “mounting or setting board” is a small piece of high density, closed-cell foam at least 1-inch in thickness. Rectangular pieces of blue or pink foam insulation are ideal. However, other types of foam insulation will work, even pieces of foam packing used to brace computers, televisions, and other electronics during shipment will do in a pinch.

Image credit: NaturePlus Beetle Blog

Cover the setting board surface with a sheet of bond-type copy paper (recycle those printing debacles from the trash). The purpose of which is to prevent the tarsal claws of specimens clinging to the surface of the insulation and breaking off when removing the dried, set specimen.

 Insect pins are like brushes to painters - buy quality. There has been considerable debate on which are the best insect pins especially since the classic Elephant brand is no longer being produced. I do not recommend trying to pinch pennies here. Since the demise of Elephant brand, I have been using and recommend the “Koštál” brand produced in the Czech Republic.

Insect pins are about 1.5-inches (37 mm) in length and graduated according to gauge (= thickness) by a series of numbers, 000 - 7. The lower the number, the smaller the gauge. Always use proportionately sized pins to the specimen being pinned. That is, a number one or two pin would be suitable for a small buprestid or tiger beetle; a number three for a large cerambycid.

The pins are available in two finishes or coatings: black enameled or stainless steel. Stainless steel are recommended for use in humid tropical climates as a rust deterrent; not much of a concern here in the southwest. Their cost is usually a few dollars more per pack of 100 than the black enameled.

Image credit: theskepticalmoth.com

Minutens

For very small beetles (< 5mm), I prefer the “double mount” method using minutens, short pins, 12 mm in length, without heads. The specimen is pinned as usual (through the upper right elytron), then inserted into a small rectangular piece of poly foam, preferably plastazote. Pinning requires a certain amount of patience and dexterity while working under a microscope or optivisor. 

Image credit: purdue.edu

Of course, there is the traditional “point” method using some type of adhesive (PVA glue or clear fingernail polish) to attach the specimen to the tip of a small paper triangle. Depending on the amount of adhesive used, the mount may be problematic.

Double-mount pinning method for very small Coleoptera

I do not advocate the use of “glue boards” (Aufklebeplattchen), a European method of mounting specimens, mainly because once the specimen is glued in place, it is impossible to examine beneath the specimen that may have  diagnostic characters (connate abdomeres, apical ridges, trochanter setae, emarginate mentum, etc.). To do so, you would have to relax and remove the glued specimen from the board, ... is that really something you would want to attempt with a series of specimens?

So then, for the average beetle specimen, here are the basics needed.










I suggest a pair of “vial forceps” for removing specimens stored in alcohol.

Continued ...

Vial forceps from BioQuip.com

© Delbert La Rue 2014. All Rights Reserved.