The Truth about Dragonflies/ A Naturalist Perspective

I did some research on the internet about dragonflies. It's been a really warm winter here and I'm expecting to see a lot of interesting bugs this year. Dragonflies can be thought of as opportunistic predators who have a wide range of dietary preferences which happen to include eating mosquitoes and some other insects we find distasteful like flies and gnats. Dragonflies are well equipped predators who have evolved over millions of years, and are able operate efficiently in both in their aquatic environment and in flight....  

Most of the life cycle of the dragonfly is spent in a predatory immature stage living in the water. There are probably  at least some 5,000 species of dragonflies or more worldwide. Dragonflies species may differ in many aspects. Depending on species for example, the immature aquatic stage for example, could last from a few months to a several years.  Dragonflies hatch from Eggs which, depending on species, will be laid on vegetation near or over water, sometimes eggs are placed  directly in the water. They will then all emerge from the eggs as nymphs.

 Nymphs ( or dragonfly larvae) look very different from the adults. They still have six legs, two antennae, but rounder more filled out bodies.  They can usually be found hiding in the rocks or in the silt under the water. Nymphs are able to launch themselves rapidly through the water through specialized gills.  They are equipped with a retractable mouth part (prehensile labium) which can be thought of as a kind of extendable jaw.  Nymphs diet includes catching and eating worms, mites or any smaller insect they can catch. Nymphs have been observed eating  tiny fish fry, tadpoles, even smaller nymphs. Thankfully their diet also includes eating mosquito larvae and other invertebrates we find harmful or annoying.

Adults will emerge after a series of several nymph growth molts. When they are ready for maturity they climb out on some vegetation, split their "skin" and the vastly different, four winged, big eyed, long bodied, six legged adult emerges. There is no intermediate metamorphic stage.

Adult dragonflies are thought to be one of our fastest flying insects, having been clocked at going 30- 35 mph hour in bursts of speed. They are agile fliers and can fly backwards, forwards and are able to hover briefly. Adults use several of their legs to make a kind of cage to capture other flying insects. They can crush and eat their prey with their well developed mouth parts. Large compound eyes enable them to sense a wide range of prey movement from many different directions. As predators, adult Dragonflies eat flying insects they can catch. Dragonflies have been reported eating butterflies and bees, for instance. Adults also eat mosquitoes and other insects we consider as "pests" as well.

 Dragonflies usually be distinguished from their close relatives the damselflies as most species of dragonflies keep their wings stretched out to the sides of their body even when at rest. They come in many colors and their wings have different patterns and spots. Dragonflies are active during sunny day time hours. The one I  found sunning itself in a field in late October, in the Hudson Valley area of NY was probably (as an adult) near the end of it's life cycle. Only the nymphs stage dragonflies can remain active in their aquatic environment during our temperate zone cold winter months. The frosts kill the adults who will have already mated and laid their eggs.

Only a few species of Dragonflies migrate.  Dragonflies depending on species, can often be found near bodies of water such as ponds, streams or lakes, in or near swamps and wetlands, sometimes further inland. Many species prefer fresh water habitats. Dragonflies are very susceptible to water pollution.

Some things I found helpful:
Using the Order name "Odonata" in searches. Looking at Field Guides. Surfing the internet for
State and Country websites which will often post species that are native to our areas,checking out international dragonfly organizations. I also found the website  ucmp.berkeley.edu/arthopoda/uiramia/odonata very helpful in trying to understand more about entomology.