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The Society for the study of flies (Diptera)

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#1 2016-08-08 11:25:46

Jaybee
Registered user
Name: John Bridges
Registered: 2013-06-30
Posts: 26

Forgive my presumption that I know what I am talking about.

It's always a bit tricky when a numpty novice like me wishes to pass on a tip to experts and non-numpties.
It can go one of two ways - you show yourself up or just now and again what you have to say may be of interest.
I've never ever worried about showing myself up but I can only hope this is of interest.

My prime reason for collecting hoverfly specimens revolves around taking close up shots that show salient features for ID purposes.
Once I have finished with the specimen they are shipped off to Roger (Morris) for final confirmation of identification for my submitted records.

To begin with the big issue for me was how specimens changed as they dried and in particular the deterioration in the eyes.
I can understand now why people who have looked at specimens for years are reluctant to venture into ID from photos - dry specimens and photos of live specimens are a world apart in colour etc.

To cut a long story short I came up with this solution which suits my purposes fine.
All specimens are dispatched using Acetone free nail varnish remover, pinned and placed inside of an air tight plastic box (I blag these from local sweet shop)
Along side of the specimens I place a single Wet wipe (containing moisturiser) - Wilkos own brand work well.
With the lid firmly in place the box then sits in my very warm, tiny computer room on top of one of my servers (so gets even warmer)
This evaporates the moisture in the wet wipe (it is changed when dry and moisture is regularly wiped from the inside of the lid etc to prevent specimens getting dripped on)
The specimens have never seen the inside of a fridge or freezer and seem happy with that.
The only time they go in the fridge is when I bag them up individually to send to Roger.
I can't testify to the archive possibilities but certainly for a period of a few weeks it seems to be a decent method of keeping specimens fairly "fresh"

This had been in "The box" for two weeks prior to photographs
http://northeastwildlife.co.uk/temp/esfp.jpg

Some of these specimens have sat in this warm box for over three weeks waiting to be photographed - each is still very flexible and "bendy" smile
http://northeastwildlife.co.uk/temp/box.jpg

Last edited by Jaybee (2016-08-08 11:29:22)

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#2 2016-08-08 18:41:54

conopid
DF Members
Name: Nigel Jones
From: Shrewsbury
Registered: 2008-02-27
Posts: 637
Website

Re: Forgive my presumption that I know what I am talking about.

Interesting. Although I have not tried it myself, some people immerse pinned specimens in acetone and this appears to preserve specimens in near mint condition for a long time. The technique is described (by Jari Flinck) in the photo.


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Nigel Jones
Shropshire

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#3 2016-08-08 21:22:50

brianh
DF Members
Name: Brian Harding
From: Kidlington, Oxfordshire
Registered: 2008-10-27
Posts: 323

Re: Forgive my presumption that I know what I am talking about.

I think that the Flinck technique has more to do with degreasing.
If I have the occasional greasy specimen then I immerse in ethyl acetate, or more usually in 2-ethoxy ethanol, followed by ethyl acetate.
This is an effective treatment and restores true colours.
By removing the fat then the specimen is more likely to remain in good condition for a long time.

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#4 2016-08-10 00:56:02

conopid
DF Members
Name: Nigel Jones
From: Shrewsbury
Registered: 2008-02-27
Posts: 637
Website

Re: Forgive my presumption that I know what I am talking about.

Just to confirm that Jari Flinck does use the acetone technique to preserve specimens in pristine condition, rather than for degreasing. The discussion thread that this was taken from was all about keeping specimens in top condition.


Nigel Jones
Shropshire

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#5 2016-08-10 11:31:09

brianh
DF Members
Name: Brian Harding
From: Kidlington, Oxfordshire
Registered: 2008-10-27
Posts: 323

Re: Forgive my presumption that I know what I am talking about.

As Flinck says in his last sentence this technique does degrease, and that may be the reason that the flies remain in pristine condition.
I use a similar method to the main post prior to pinning, but occasionally the flies do get a bit damp.
For me it is probably more important to get them pinned quickly, before allowing them to dry for long term storage.

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#6 2017-07-10 16:55:44

KenMerrifield
Administrator
Name: Ken Merrifield
Registered: 2008-02-21
Posts: 227

Re: Forgive my presumption that I know what I am talking about.

I had intended to respond earlier to mention that chopped Laurel leaves are an alternative method of keeping specimens moist and the cyanide gas released from young leaves inhibits mould formation. I have found that Laurel leaves seem to preserve Tabanid eye patterns for a number of months.
There was an article on the use of rehydration to restore eye colouration (p10- 15) in Fly times a while ago-
http://www.nadsdiptera.org/News/FlyTimes/issue48.pdf

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