Nature's biplanes

[Berman]

This is regarding dragons and damsels. Flies that is. On my property in Oregon, USA there are many different species. I was observing a group of Blue Eyed Darners(Rhionaescha multicolor according to my guidebook). There is a kind of stroboscopic effect  as  their wing flapping has a very short stroke and the center of this stroke happens twice per cycle. When they are flying directly towards you, they seem to have a biplane appearance as the rear wings are mounted lower on the thorax. Incredible fliers. Sixty kilometers per hour in a straight line. Change of direction or altitude in a flash. I often wonder if they can independently control the speed, dihedral, and angle of incidence of each wing. I closely looked at the wing of a dead specimen. The venation, of the leading edge and "spars", is composed of a series of rectangles for maximum rigidity. The trailing edge is a series of pentagons composed of two ninety degree angles at the trailing edge and the inner portion made from three sixty degree angles. The center part of the wing is made up from a series of random "lozenge like" polygons to maximize flex and create a pocket of air on the downstroke.
 Many of the males and females of the same species have different colors and markings. Today, I spotted a female River Jewelwing damselfly, male Varigated Meadowhawk,male Flame Skimmer,male Widow Skimmer, plus male and female Blue Eyed Darners which are the most plentiful.

[Des]

I have an outdoor fish pond and during summer it attracts a number of Dragonflies. I sit and watch these amazing creatures with their incredible flight characteristics, they hover motionless for long periods of time, skim the water with their abdomen, and catch smaller insects in mid flight, I watched one catch seven smaller insects in a matter of half a minute with some amazing aerobatics. The colour of these Dradonflies vary from a vivid red, a bright yellow to an olive drab colour, with the sun hitting them they make for a very impressive display, just one of natures amazing creatures.

Des.

[lone modeller]

Dragonflies are among the oldest known insects. They were well developed during the Carboniferous Period (known in America as the Pennslyvanian about 300m years ago)) where specimens have been recovered from coal seams with a wingspan of 1 meter (3 feet). Just how these monsters breathed is still a mystery to palaeontologists - some have suggested that oxygen levels in the atmosphere must have been much higher than at present. I am skeptical of that for a number of reasons and think that they had a different system of breathing to modern examples, but be that as it may. They are also common in certain strata in the Jurassic (about 180 - 120m years ago) where they are not so large. Obviously fossils cannot tell us about their flying capabilities but it is plausible that they were accomplished fliers from an early stage.

Here in the UK we see them in the summer months with the related group the damsel flies. The colours are most striking, as is their speed of flight. As Berman and Des have commented, they are strikingly beautiful creatures - unless you are a smaller insect! Look out for them - they are a joy to watch.

Stephen.

[Berman]

 Festo is a very large engineering company that sometimes designs incredible flying mechanisms just to prove that they have to skill to do so. They built a radio controlled dragonfly(BionicOpter appears to have about an eighteen inch wingspan) with extremely complex wing movements.  It is able to hover and turn like a real dragonfly. More info on their website.
 They also built helium filled penguins that fly by flapping their wings (flippers). These feature autonomous altitude control and collision avoidance. Unfortunately none of these creations are available for sale. Would be incredibly expensive if they were.
 In the USA, a robo hummingbird was built. Duplicates the size and flight of a real hummingbird. Has successfully flown for up to eleven minutes on a battery charge.

[coyotemagic]

Here in the Sierra Foothills of Northern California, our average adult dragon fly is about 3 inches in length and they keep our wasp population in check.  They are indeed a joy to watch.  We also have a wide variety of swifts and swallows that do their hunting and feeding on the wing at dusk.  As brilliant flyers as they are, they're no match for the dragon flies.  With such marvelous creatures as these, it's no wonder early man dreamed of flying.
Cheers,
Bud

[lcarroll]

   We have droves of Dragon Flies here as well, given our mosquito and fly populations it's like a Gourmet Food Court for them! Although I enjoy watching their flight displays it's these little Guys that I admire for flying ability. Two males dog fighting is an incredible display of the flyers art, never thought I'd see birds "wrap it up" like these little fellows can. We run several feeders to keep them coming back every summer, they are only here in the North long enough to mate, produce a brood, and then head south for the long winter. They arrive here mid May and even the stragglers are gone by end August.



   They compete with the wasps for the feeder rights constantly, you can see their "smallness" with the Yellow Jacket in view.



    Photos by my Brother on a visit here, he's a professional Photographer.
Cheers,
Lance

[Alexis]

Lance is right , here in the summer when you look up at the sky there are hundreds flying around ! Very cool indeed .  One dragonfly can eat up to 300 insects per day . The consume all other flying insects as well as ants .




Terri