Extraction and thrips and other whole or equivalent insects from frozen blackberries and raspberries: collaborative...

A method was developed for the extraction of thrips and other whole or equivalent insects from frozen blackberries and raspberries. The method consisted of a thawing and drained weight step, followed by acid maceration. Berries were wet-sieved over a No. 25 sieve nested in a No. 80 sieve. The berry tissue retained on the No. 80 sieve was dehydrated with isopropanol and then treated with chloroform. The chloroform was stripped from the residue with isopropanol. The berry residue was extracted with light mineral oil from a 40% isopropanol-Tween 80-Na4EDTA mixture. The collaborative study was successfully completed with 83.3% average recoveries of thrips and 19.2% coefficient of variation. The method has been adopted official first action.