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(invertebrate zoology)
The dragonflies, an order of the class Insecta, characterized by a head with large compound eyes, and wings with clear or transparent membranes traversed by networks of veins.



(dragonflies and damselflies), an order of predatory insects capable of rapid flight. The large insects have a mobile head, large eyes, short bristle-like antennae, four transparent wings richly netted with veins, and a long, slender abdomen.

There are three suborders: Zygoptera, Anisoptera, and Aniso-zygoptera. The last suborder is common in Japan and India and includes a single genus, whose forms combine the features of the first two suborders. The Zygoptera have narrow fore and hind wings of nearly the same shape, which are pressed together and raised upward when at rest. In the Anisoptera the wings differ in shape and lie horizontally when at rest; the base of the hind wings is wide. The wing and the abdomen measure 10–94 and 14–120 mm long, respectively.

Dragonflies and damselflies feed on other insects that they seize in flight. They are considered beneficial owing to their destruction of mosquitoes, black flies, and other injurious insects. The insects do, however, spread protogonimosis, a dangerous disease of poultry.

Dragonflies copulate while in flight. The secondary copulative apparatus of the males is highly specialized and has no analogues among other insects. The eggs are laid in water, in the tissues of aquatic plants, or, less commonly, in wet soil. The larvae develop in water and breathe by means of gills. Zygoptera larvae have the trachéal gills at the caudal end, and the Anisoptera larvae have the rectal tracheal gills on the walls of the rectum, which is periodically filled with water. Metamorphosis is incomplete. The larvae have a very long lower lip that forms a prehensile organ, the mask, which protrudes when seizing prey and conceals the jaws when at rest. The larvae are predators, feeding on aquatic insect larvae and, sometimes, attacking tadpoles and fry. They serve, in turn, as food for fish.

At the end of the developmental period, the larvae emerge from the water and attach themselves to plants or uneven places in soil. The last molting occurs on land near a body of water. Some species can fly great distances away from water. During mass flights Libellula quadrimaculata forms a dense swarm stretching dozens of kilometers.

There are about 4,500 species, most of which inhabit the tropics and humid subtropics. About 165 species are widely distributed throughout the USSR except in arid regions.


Zhizri zhivotnykh, vol. 3. Moscow, 1969. Pages 254–59.


References in periodicals archive ?
Consequently, odonate species may be good indicator species for the quality of aquatic habitats (e.
Odonate field guides are becoming common, and this book ranks among the best available.
2003) have described methods for rearing odonates in the laboratory, but these methods often require laborious techniques, especially when rearing large numbers simultaneously.
Abundance of odonates during monsoon period at St I, III and IV was directly related to the luxuriant macrophytic growth (Cronin et al, 2006)[78].
To complicate matters, Oregon has eight eco-regions, so to spot all the possible species of odonates requires a good deal of travel.
What happened next led to the biology teacher's continuing enchantment with odonates, an order of insects that includes dragonflies and their relatives, damselflies.
The comprehensive chapters on the biology and ecology of Irish odonates, photography, and field work make it an invaluable reference for odonatologists, amateur naturalists and enthusiasts alike.
In Kenya, tree holes with fewer mosquitoes are associated with the presence of odonates in them (19).
Despite their importance in aquatic ecosystems, there is little field or laboratory data regarding the impact that environmental chemicals have no odonates.