THE DRAGON-FLY AND ITS VICTIM
(Macromia sp.)
Who would suspect, as one of these dragon-flies darts by him on the roadway, that every few minutes its jaws are crunching some helpless insect caught in its flight?
When I caught the dragon-fly whose picture is shown here, I held him by the wings, and, catching a fly that buzzed about the table, dropped it in his claws. Without a moment’s hesitation his mouth opened wide and closed upon the fly. I watched it disappear underneath his great upper lip and almost fancied I could hear its shell crack as the powerful jaws and lower lips turned it around and around in the mouth. A few seconds only, and the sucking throat had drawn out all the blood and the lips threw out a ball-like mass made up of the fly’s wings, legs and crushed body skeleton. Then it opened again for more.
One entomologist has said that in two hours a dragon-fly will eat at least forty house flies, and Doctor Howard says that if starved for food it will eat up its own body.
No doubt these dragons of the air are to be counted as among our greatest friends, and in places in the East where life is made a burden by that humming, stinging pest, the mosquito, its presence in great numbers helps amazingly in keeping down the day-flying forms of that insect. It has gone into the Hawaiian Islands with the mosquito and has learned there to breed in the water found on the leaves of lilies growing on dry land.
Perhaps someone will find a way to domesticate this creature and make it live upon the house flies around the house. As a first step, Needham has fed the larvæ on bits of meat.