Compound eyes large, often covering most of the head Four membraneous wings with many veins and crossveins Base of wings narrow, stalk-like One distinctively pigmented cell stigma on leading edge of wing Abdomen: They may also catch and eat honey bees — then they are regarded as pests by the beekeepers. In some parts of Europe, dragonflies are considered a threat to the poultry industry because they transmit Prosthogonimus pellucidus,a parasitic flatworm.
See Article History Alternative Title: The adults are easily recognized by their two pairs of narrow, transparent wings, sloping thorax, and long, usually slender body; the abdomen is almost always longer than any of the wings. Large, active by day, and often strikingly coloured, they are usually seen flying near water.
Odonata is an order of carnivorous insects, encompassing the dragonflies and the damselflies. The Odonata form a clade, which has existed since the Triassic. Dragonflies are generally larger, and perch with their wings held out to the sides; damselflies have slender bodies, and hold their wings over the body at . Odonata definition is - an order of insects containing the dragonflies and damselflies and characterized by aquatic larvae that are nymphs or naiads and by predaciousness in both adult and larval forms. Introduction. Odonata are an order of aquatic palaeopterous insects. There are about extant species in just over genera. Adult odonates are medium to large in size, often conspicuous and/or brightly colored insects and .
Adult odonates are voracious predators, as are the aquatic larvae. The name dragonfly is commonly applied to all odonates, but it is also used to differentiate the suborder Anisoptera from the suborder Zygoptera.
The order Odonata is small and well known; the total number of living species Order odonata does not greatly exceed the 5, or so already described. Odonates are globally distributed from the tropics, where they are most numerous and varied, to the boreal forests of Siberia and North America.
They are also found throughout the Southern Hemisphere, with the exception of Antarctica. Ross While the basic structure of adults is uniform, coloration is highly variable—hues range from metallic to dull, sometimes in combination.
There is also a wide range of sizes; damselfly species have both the shortest and longest wingspans—about 18 mm and 19 cm 0. Click each stage to view details.
Odonates are among the few insects that have secured a major place in folklore and art. In Japan, where a journal Tombo has been devoted to reports of their biology sincedragonflies Odonata traditionally have been held in high regard.
In other Asian cultures they are considered benign and auspiciousbut in Europe they have often been perceived as threatening, even though they do not injure humans. The young, termed larvae or sometimes nymphs, are functionally wingless and live in a variety of shallow freshwater habitats including tree holes, ponds, marshes, and streams.
They are often bottom-dwelling and are well-camouflaged, their mottled or drab colours matching the sediments or water plants around them.
Although large numbers of mosquitoes and other insect pests are consumed by larvae and adults, odonates are generally indiscriminate feeders that seldom affect humans economically. Larvae, however, have been used successfully in Myanmar to interrupt transmission of the mosquito-borne disease dengue.
Natural history The larval stage Eggs are laid in or very near water exceptions include the terrestrial larvae of a few Hawaiian damselflies Megalagrion and Australian woodland dragonflies of the genus Pseudocordulia.
The hatchlings then develop through a series of stages, or instarsmolting at the end of each instar into similar, but larger and more developed, versions of themselves.
Very soon after leaving the egg, the first instar prolarva sheds its cuticular sheath, releasing the tiny, spiderlike larva. Because it is aquatic, the larva differs markedly in structure and behaviour from the flight-oriented adult.
Wing sheaths are not even apparent in the early instars; it is not until about halfway through larval development that they appear, becoming rapidly larger during subsequent molts.
Larvae molt approximately 8 to 17 times, and some grow to more than 5 cm 2 inches in length. The number of instars varies both within and between species.This chapter introduces the insect order Odonata.
It provides the most recent phylogeny and up-to-date systematics as well as genera and species numbers of the various families in the biogeographic regions. Order: Odonata Dragonflies and Damselfies The key for Odonata can be found in Chapter 5 of the Guide to Aquatic Invertebrates of the Upper Midwest, pages Introduction.
Odonata are an order of aquatic palaeopterous insects. There are about extant species in just over genera. Adult odonates are medium to large in size, often conspicuous and/or brightly colored insects and .
The order Odonata includes dragonflies and damselflies, dedicated predators of other insects. Odonates begin life in ponds, streams, and other freshwater sources.
This site is designed to make available what we know about the distribution, biogeography, biodiversity, and identification of Odonata (dragonflies and damselflies) in the Western Hemisphere. Use the navigation bars at . An online resource devoted to North American insects, spiders and their kin, offering identification, images, and information.