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#1 2017-10-01 21:09:12

SKirk
DF Members
Name: Array Array
Registered: 2017-09-24
Posts: 2

Beginners preservation question

Hello,
Forgive the enquiry, but having just taken an interest in diptera I've started collecting a few specimens to examine. I've noticed that one tephrid specimen has turned very dark/black since pinning it. Is this an issue with preparation or just something that can happen (and if so how can it be avoided)?
Many thanks
Simon

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#2 2017-10-02 19:21:31

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

Re: Beginners preservation question

Simon, your specimen has gone greasy - it happens, but not very frequently. I copied this text from  http://www.thornesinsects.com/en/info.html :

SPECIMENS THAT GO GREASY
SOME SPECIES OF INSECTS EXUDE GREASE AND OILS FROM STORED FOOD FATS ONCE THEY HAVE DIED. THIS CAN HAPPEN AT ANY TIME. THIS MOSTLY OCCURS IN SATURNID MOTH MALES, NOT SO MUCH THE FEMALES. MORPHO SPECIES ARE WELL KNOWN FOR THIS AND THE COLLECTORS OR BREEDERS REMOVE THE ABDOMENS, WHICH IS WHERE THE OILS ARE STORED. THE OILS WILL SOMETIMES STAIN THE WINGS. MANY OF THE SATURNID MOTHS ARE NOW STARTING TO RECEIVE THE SAME TREATMENT WITH ABDOMENS BEING SENT SEPERATELY. THEY CAN EASILY BE GLUED BACK ON AFTER THE ABDOMEN HAS BEEN TREATED WITH ACETONE. ALTHOUGH ALL PRECAUTIONS ARE TAKEN NOT TO SEND A GREASY SPECIMEN THIS MAY HAPPEN OCCASSIONALY AS IT CAN EVEN OCCUR IN TRANSIT. THERE IS A SIMPLE REMEDY TO FIX ANY OIL PROBLEM THAT OCCURS AND ONE CAN USE THIS ON OLDER SPECIMENS IN A COLLECTION AS WELL. BUY A CAN OF ACETONE FROM THE HARDWARE STORE OR AUTOMOBILE SUPPLY STORE (IN CANADA CANADIAN TIRE IS THE PLACE). PUT SOME ACETONE IN A PLASTIC CONTAINER WITH A GOOD LID TO PREVENT EVAPORATION AND SPILLS. PLACE YOUR ENTIRE SPECIMEN, PINNED OR FOLDED, INTO THE ACETONE. THE SPECIMEN, WINGS AND ALL, WILL SOAK UP THE ACETONE. AS ACETONE IS A SOLVENT IT WILL LEACH OUT THE OILS FROM THE SPECIMEN. USUALLY ABOUT A HALF HOUR IS LONG ENOUGH. SOME SPECIMENS WILL TAKE LONGER, PARTICULARLY SOME OF THE REALLY GREASY BEETLES BUT YOU WILL LEARN HOW LONG IS NECESSARY AS YOU BUILD EXPERIENCE WITH THIS. WHEN SUFFICIENT TIME HAS ELAPSED REMOVE THE SPECIMEN FROM THE ACETONE AND PLACE ON A PAPER TOWEL AND LET IT AIR-DRY AT ROOM TEMPERATURE. IT SHOULD REMOVE ALL THE GREASE AND SPECIMEN WILL APPEAR FRESH AND NEW. SOMETIMES WITH REALLY HEAVILY GREASED SPECIMENS ONE MAY HAVE TO REPEAT THE PROCESS. IT MAY NOT ALWAYS WORK 100% OF THE TIME BUT IT IS THE BEST METHOD THERE IS. ONCE YOU ARE DONE NEVER USE THAT ACETONE AGAIN. ALWAYS USE FRESH ACETONE FOR THE NEXT DEGREASING JOB EVERY TIME.


Nigel Jones
Shropshire

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