Death to thrips!

A simple soul, Lord Marshmoreton - mild and pleasant, yet put him among the thrips and he became a dealer-out of death and slaughter, a destroyer in the class of Attila the Hun and Genghis Khan. Thrips feed on the underside of rose leaves, sucking their juice and causing them to turn yellow; and Lord Marshmoreton's views on these things were so rigid that he would have poured whale-oil solution on his grandmother if he had found her on the underside of one of this rose leaves sucking its juice.

(From A Damsel in Distress, by Sir Pelham Wodehouse)