Fig. 183.—May fly.
Among all the insects of the field and swamp none are more familiar than the dragon fly (Fig. 184), which children were once led to believe had a vicious habit of sewing up the eyes and mouth of any one; hence the name "darning needle." These insects are often beautiful, with their rich wings of glistening lace, four in number, their bodies gleaming in tints of bronze, blue, and black. The abdomen is long and slender, like a needle; the head is prominent and armed with powerful jaws; the eyes are large and compound, with several single eyes as well. Some dragon flies are very small. Others are large, as those of the Malay Archipelago, where the natives trap them and use them for food. The dragon flies are hunters, preying upon other insects which they capture on the wing, and large forms have been seen taking very young fishes from the water, swooping down upon them like hawks.
Fig. 184.—Dragon fly.
Fig. 185.—Larvæ of a dragon fly.
The development of the dragon fly is interesting from the fact that the young lives a long period in the water. The eggs are deposited in the water, hatching out into curiously shaped creatures (Fig. 185), which are among the most ferocious of all the water insects. They pass two years in this form, preying upon other animals and even small fishes. The larva has a proboscis which ordinarily folds over the face and is called the mask (B), but when an insect approaches, this strange appliance with powerful jaws or hooks is shot out (A) with dire results. After the two years have passed the pupa, as it is called, climbs up a stem, leaves the water and casts its skin, appearing as a full-grown dragon fly ready for a life of rapine on land.
Fig. 186.—Ant lion, adult and larva.
