Its eyes and body are the color of mud and must be very hard to see.
This photograph shows the mask in place, the grinning mouth a long curved slit across the face, while resting on the ground, as one would rest one’s elbow on the table, is the powerful claw arm, so strong that you would find it difficult to pull the mask away, or having done so to keep it down.
DRAGON-FLY NYMPH UNMASKED
(Libellulid)
Pulled down from the mud dragon’s sheep-nosed face, the mask is resting on the ground. It can be stretched out much further and also opened up to form a pair of powerful claws. Along the edge of the mask is a fringe of inward-pointing spines like those which edge the leaf margins of a venus flytrap. The eyes are large and many-faceted and form the blunt-pointed corners of its head.
The under-water battles in which these mud dragons, or dragon-fly nymphs, take part must be something terrible. It is recorded that in Hungary 50,000 young fishes were put into a pond in which enormous numbers of these nymphs occurred and only fifty-four fishes survived. One is not surprised to learn, too, that they will eat each other up.
On the whole, however, it is doubtful if between the flies and other injurious insects which the dragon-flies destroy in the air, and those larvæ of mosquitos which the water nymphs destroy in the ponds, there is any other family of insects toward which man should feel more indebted than toward the family of the odontata or dragon-flies.