Dehydration and clearing
1. Place up to 20 thrips in an excavated block in clean 60% alcohol
- with very large thrips species place fewer specimens in each dish.
2. Remove the alcohol with a pipette, add a few drops of distilled
water then an equal number of drops of 5% NaOH solution. Pale specimens
may require only one hour, others can be left overnight, black specimens
may be left for 2 or more days. The exact period can only be determined
by experience, but should always be as short as possible to minimise
damage.
3. Transfer the specimens from NaOH solution to 60% alcohol, using
a needle or wire loop. Gently massage each specimen to expel most
of the body contents, and spread the legs and antennae.
4. Store the specimens in 60% alcohol for 24 hours.
5. Replace the 60% alcohol with 70% alcohol and leave for about
1 hour; unmacerated specimens must be punctured to speed the entry
of alcohols, and the legs, antennae and wings should be spread.
6. Replace with 80% alcohol and leave for 20 minutes.
7. Replace with 95% alcohol and leave for 10 minutes.
8. Replace with absolute alcohol and leave for 5 minutes.
9. Replace with fresh absolute alcohol and leave for another 5 minutes.
10. Transfer to clove oil and leave for about half an hour before
mounting.
NOTES: Alcohols and clove oil will absorb water from the atmosphere
if not protected, particularly under warm humid conditions. The
objective of the dehydration schedule is to remove water, then to
render the specimens translucent with clove oil. Clearing can be
improved by massaging each specimen gently with the back of a bent
needle.
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