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Distinguishing features ofdragonflies include fore andhind wings dissimilar in venation paleoptera and, usually, shape; discoidal cell divided into two triangular areas; eyes contiguous or nearly so; and larvae stout and without caudal lamellae.

Superfamily Aeshnoidea

The south Australian and South American family NEOPETALIIDAE (nine species) contains the most primitive of recent dragonflies. The PETALURIDAE (11 species) is also an archaic family within which are found the world's largest extant species with wingspans of more than 16 cm. Their larvae are semiaquatic burrowers, living in swamps or beside steams. The AESHNIDAE form a large and cosmopolitan family of about 375 species of large, strongly flying insects characterized by their enormous eyes that meet broadly in the midline of the head. Larvae are mostly stout, elongate insects found among vegetation in a variety of still- or moving-water habitats; a few, however, are semi-terrestrial or terrestrial. The GOMPHIDAE (800 species) is another primitive family whose adults have widely separated eyes and are generally black and yellow, with one or the other color predominating according to the habitat in which they are found. They have a rudimentary ovipositor, and eggs are laid by simply dipping the tip of the abdomen into the water. Though some gomphids breed in still or sluggish waters, most breed in flowing water, and often their eggs have an adhesive exochorion or ropelike filaments that may prevent their being washed away. Gomphid larvae are burrowers or sprawlers in the substrate, and some burrowing species have a greatly elongated 10th abdominal segment in order to retain respiratory contact with the water and fossorial forelegs.

Superfamily Cordulegastroidea

This superfamily contains only one small family CORDULEGASTRIDAE (60 species), with a palearctic and oriental distribution. Its members carry a combination of aeshnoid and libelluloid characters. Some species are open-country forms that breed in small ponds or streams; others are associated with mountain streams.

Superfamily Libelluloidea

Both the CORDULIIDAE (Figure 6.12) and the LIBELLULIDAE are large, cosmopolitan families, though the former is a paraphyletic group. Corduliids (360 species) breed in a range of still- and moving-water habitats, including temporary pools and swamps, and the larvae of some species are able to withstand limited desiccation. A few species have terrestrial larvae. Libellulidae (900 species) principally breed in still-water habitats, though larvae of some species are stream dwellers. Larvae of most species are secretive, hiding among rotten vegetation at the bottom of the pond or lake; a few others have become secondarily adapted for a more active existence among growing vegetation. Adults vary greatly in size and coloration, the family including some of the most strikingly marked Anisoptera with pale wings bearing spots or bands of pigment, commonly dark but sometimes bright shades of orange or reddish brown.

FIGURE 6.12. A dragonfly, Macromia magnifica (Corduliidae). (A) Adult male; (B) larva, dorsal view; and (C) larva, lateral view with labium extended. [Reproduced by permission of the Smithsonian Institution Press from Smithsonian Institution United States National Museum Proceedings, Volume 49, 'Notes on the life history and ecology of the dragonflies (Odonata) of Washington and Oregon,' July 28, 1915, by C. H. Kennedy: Figures 134, 146, and 147. Washington D.C., U.S. Government Printing Office, 1916.]

FIGURE 6.12. A dragonfly, Macromia magnifica (Corduliidae). (A) Adult male; (B) larva, dorsal view; and (C) larva, lateral view with labium extended. [Reproduced by permission of the Smithsonian Institution Press from Smithsonian Institution United States National Museum Proceedings, Volume 49, 'Notes on the life history and ecology of the dragonflies (Odonata) of Washington and Oregon,' July 28, 1915, by C. H. Kennedy: Figures 134, 146, and 147. Washington D.C., U.S. Government Printing Office, 1916.]

Beekeeping for Beginners

Beekeeping for Beginners

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