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Hi Steve & All,
To paraphrase Mark Twain, the necessity of expensive gadgets is
greatly exaggerated by expensive gadget salesmen. That is their job.
Extracting a pinned or pointed insect from a Styrofoam pad and
inserting it at a different angle, without damage to the voucher, is as
easy as rolling off of a log in rough water. Styrofoam is mostly air,
after all, so pins slip in easily, slip out easily and the hole closes
almost as fully as a hole in water does when a solid object is
extracted. Thus the same pad has served for many thousands of pin changes.
And one should not handle pinned insects while wearing boxing
gloves; especially in the dark or in haste.
{On an interesting side note; Styrofoam shrinks to about 5% of
original volume when in close contact with crystals of
paradichlorobenzene. And I agree; when glueing something to Styrofoam a
glue which does not dissolve Styrofoam is indicated. }
On the other hand, pinning Arthropods which have a hard exoskeleton
or pointing tiny fragile/ appendage knotted vouchers, free of damage or
without obscuring diagnostic features, can be a genuine challenge. More
so in spades if a new batch of pointing liquid fails to harden as
intended and things gradually spiral off of the points over a period of
months (This happened once when my 1960 batch ran out}.
At times static electricity causes very light insects to leap away
from a poised point just before contact.
Pinning and pointing these delicate things is however good training
for tying a midge fly on a #16 hook. And yes Paul; it worked great one
evening when all else had failed.
YT, DW, Kentville
On 6/28/2020 1:36 PM, Stephen Shaw wrote:
> Hi Dave,
> A nice inexpensive idea, but it only gives rotation about one axis, so to see more angle you’d have to repeatedly reposition the pinned insect’s pin in the styrofoam - feasible over small angles, but not a great idea anyway with delicate mounted insects. Maybe lichens are more resilient. Also, the solvent in many glues will dissolve styrofoam — regular aquarium sealant works fine.
>
> A device for rotating in all 3 axes X, Y & Z is technically called a goniometer. I’ve made several such miniature Heath Robinson/Rube Goldberg devices for microscopic photography of pinned insects over the years. A cheap large one, size like yours, used to be available from Bioquip in California — I have one bought years ago, maybe $20. Bioquip now lists only the ultra-deluxe stainless steel version for US$254 (!). To see its construction, identical to the one I have, google:
> https://bioquipinc.com/
> and insert 11RPSM in the search box. Must be some rich entomologists in USA — I wouldn’t pay $254 for this.
> Steve
> ------------------------------------
> On Jun 28, 2020, at 8:41 AM, David Webster <dwebster@glinx.com> wrote:
>
>> Dear All,
>>
>> I have decided to take a few minutes to describe a simple device
>> which I made many decades ago (just after fridge magnets appeared) to
>> hold pinned insects or parts of plant material (flowers, moss, lichens,
>> liverworts...) mounted on insect pins for examination using a dissecting
>> mike.
>>
>> The Styrofoam disk has not required replacement after much use.
>>
>> Materials:
>>
>> A strip of sheet iron 16 mm wide, 9.7 cm long and 0.6 mm thick;
>> dimensions are not critical.
>>
>> A disc 20 mm diam, cut from a fridge magnet.
>>
>> A 14 mm square of Styrofoam, cut from a 5 mm thick meat tray.
>>
>> Insect pins.
>>
>> Assembly and use:
>>
>> Bend the sheet iron strip at 90 degrees to form two arms; 4 cm and
>> 5.7 cm long
>>
>> Glue the Styrofoam square to the fridge magnet disc.
>>
>> Because the diameter of this disc is slightly greater than the
>> width of the iron support one can readily raise, lower or rotate the
>> object viewed to the desired orientation. The long arm of the sheet iron
>> holder is upright for examination of unusually large material; otherwise
>> the short arm is upright.
>>
>> YT, DW, Kentville
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
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