Thrips of the British Isles
Collecting and preparing thrips
Maceration
Body contents are removed by soaking specimens in a weak NaOH solution (never more than 5%) for an appropriate period-the strength of the solution and the length of the treatment being determined by experiment. Ideally, use very weak NaOH solution (2%) overnight (for black specimens much longer), at room temperature; avoid heating, as it causes damage to setae and the body surface.
- Place up to 20 thrips into clean water in a glass staining block. Try to make some specimens float with their wings on the surface. Leave for 1 hour.
- Add to the water an equal volume of 5% NaOH solution and leave overnight (for black specimens as long as necessary).
- Transfer the specimens from the weak NaOH solution to water for a few hours, using a needle or wire loop. Gently massage each specimen to expel most of the body contents, and spread the legs and antennae.
- Store the specimens in 60% alcohol for 12 to 24 hours.
Dehydration and slide mounting
Dehydration removes water, and renders the specimens translucent in clove oil.
- Replace the 60% ethanol with 70% ethanol and leave for about 1 hour; the legs, antennae and wings should be spread.
- Replace with 80% ethanol and leave for 20 minutes.
- Replace with 95% ethanol and leave for 10 minutes.
- Replace with absolute ethanol and leave for 5 minutes.
- Transfer to clove oil and leave for at least half an hour; gently massage and stretch each specimen if necessary to prevent collapsing.