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Family Aeschnidae

This is one of the largest groups of dragon-flies, and comprises many of our largest forms. The eyes meet on top of the head. In coloration and general appearance they are much like the preceding families but with the majority of them the wings are generally clear with only apical brown spots and sometimes they are a little smoky. These large dragon-flies are abundantly found all through the summer. They are among the first to appear in spring and among the last to disappear in the autumn. Their flight is very strong, and the large species are most ferocious-looking creatures. In fact, the largest and most powerful dragonfly in the North American fauna is Epioeschna heros Fabr. One of the commonest forms which may be seen in many parts of the country is Anax junius Drury. On account of the strong flight of these insects they are frequently found far away from the place of their birth seeking their prey in the fields and about open places in the woods, busying themselves continually in the capture of flies and even larger insects. The male and female of Anax junius paired are common objects flying over the water. The female seems to prefer to lay her eggs in stagnant pools or in ponds where the surface is covered with duckweed and other aquatic plants. The female submerges her abdomen in laying her eggs. According to Williamson, this species appears in large and compact flocks, some of them numbering several hundred individuals, and they pass back and forth frequently near the ground as twilight comes on, seeking especially swarms of midges.

Six genera are represented in this country, mostly the species belonging to the typical genus AEschna.