<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
</head>
<body>
<div class="moz-cite-prefix">On 10/7/21 9:12 AM, Callomon,Paul
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:SN6PR01MB5231A9D2376A69C108D120E1C3B19@SN6PR01MB5231.prod.exchangelabs.com">
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
<meta name="Generator" content="Microsoft Word 15 (filtered
medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]-->
<style>@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}@font-face
{font-family:"Yu Gothic";
panose-1:2 11 4 0 0 0 0 0 0 0;}@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}@font-face
{font-family:"\@Yu Gothic";
panose-1:2 11 4 0 0 0 0 0 0 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0in;
font-size:10.0pt;
font-family:"Courier New";}span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;}span.EmailStyle22
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}div.WordSection1
{page:WordSection1;}</style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="WordSection1">
<p class="MsoNormal">Doug et al.,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’ve also often wondered why the insect
world persists with wooden cases. It may be because there are
few calcitic structures in most insects – my limited
understanding of them is that they are made mostly of protein
and carbohydrates like chitin – so Byne’s, which is specific
to calcium carbonate (and perhaps calcium phosphate, mammalogy
colleagues?) is less likely to rear its fuzzy head.<o:p></o:p></p>
</div>
</blockquote>
<p>Insect exoskeleton is predominantly made of sclerotin, which is a
modified form of chitin:</p>
<p>"As it matures, freshly formed sclerotin becomes a hard,
horn-like substance with a range of yellow-brown colors. As
animals adapted to life on land, increasingly diverse needs for
organic stiffening components arose (as opposed to mineral
stiffening components such as calcium carbonates and phosphates).
Among the invertebrates, this need was met largely by the
development of sclerotins and other cross-linked proteins that
allowed insects to adapt to existence on the land and later to
develop wings. Sclerotin is biochemically variable; different
species incorporate different proteins in different proportions,
and the same insect will use different compositions in forming the
different components of its body. In general, however, it is
formed by cross-linking the various protein molecules with
phenolic compounds – a tanning process under enzymatic control."</p>
<p>along with resilin, a remarkable elastomeric protein:</p>
<p>"Resilin is often found as a composite with chitin in insect
cuticle, where chitin serves as the structural component."<br>
</p>
<p>While it may not contain anywhere nearly as much calcium as a
mollusc or crustacean specimen, it seems reasonable to expect that
after decades of exposure to acid fumes, an insect specimen <b>will</b>
suffer. Given that the average insect specimen also has two or
three labels, it is probably helpful that most collections have
switched to using only acid-free paper for their labels, but - in
reality - I think the switch was made not to protect the
specimens, but to avoid problems with the labels disintegrating
over time. Of course, it might be that label disintegration has
never been solely a matter of intrinsic acidity, but exacerbated
by outgassed VOCs, in which case we may STILL have labels falling
apart decades from now, even <b>with</b> acid-free paper. That's
the kind of thing people might want to know about.</p>
<p>Why we persist is, I think, simply a matter of cost and
practicality. An insect drawer made of poplar wood with a glass
top costs less than $50, and if properly constructed affords very
good protection from dermestids and other pests, along with
structural protection from vibration and impacts and chemicals.
They can also be produced by anyone who has a modest woodworking
skill and the right tools. I'm not sure that any alternative
material (like acrylic) would necessarily be cheaper (simple
acrylic boxes seem to cost in the range of 25-50 dollars, an
acrylic insect drawer would probably cost more because of
specialized design and more limited market), or not have its own
chemical outgassing issues, but maybe it would be worth
investigating. Such investigation might be tricky, if one cannot
manufacture "test models" of alternatives easily or cheaply. <br>
</p>
<p>Peace,<br>
</p>
<pre class="moz-signature" cols="72">--
Doug Yanega Dept. of Entomology Entomology Research Museum
Univ. of California, Riverside, CA 92521-0314 skype: dyanega
phone: (951) 827-4315 (disclaimer: opinions are mine, not UCR's)
<a class="moz-txt-link-freetext" href="https://faculty.ucr.edu/~heraty/yanega.html">https://faculty.ucr.edu/~heraty/yanega.html</a>
"There are some enterprises in which a careful disorderliness
is the true method" - Herman Melville, Moby Dick, Chap. 82</pre>
</body>
</html>