Common Green Darners Mating & Laying Eggs
Darners are a family of dragonflies whose members are quite large (some over three inches in length). Common Green Darners (Anax junius) are one of only two darners in the Northeast with an entirely green thorax (section between head and abdomen). Often you find them perching low in grasses and weeds. Males tend to fly along the shorelines of ponds, patrolling for females and keeping other males at bay.
After mating takes place, the males of some species of dragonflies disappear. In other species, the male stays nearby, guarding the female and fending off other males that might remove the initial suitor’s sperm and replace it with their own. Some species go to the extreme of remaining attached to each other while egg-laying takes place. Common Green Darners are the only species of darner that often lays in this manner – in tandem, with the male still clasping the female while she submerges her abdomen and lays her eggs in aquatic vegetation (pictured).
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
“Mating Wheels”
Dragonflies and damselflies both create what are called “mating wheels” when they mate. The male grasps the female at the back of her head with the terminal appendages at the end of his abdomen and the female curls her abdomen forward until the tip of her abdomen reaches the male’s sex organs.
Many male dragonflies go to great lengths to make sure their sperm have reproductive success. Prior to mating they often remove any sperm that happen to be in the female from previous matings. In addition, depending on species, they may leave after mating, fly with and guard the female as she lays her eggs, or remain grasping the female as her eggs are laid. His proximity to the female during egg laying prevents other males from removing his sperm.
Much of this information, as well as excellent photos for identifying dragonflies and damselflies, can be found in A Field Guide to the Dragonflies and Damselflies of Massachusetts, by Burne, Loose and Nikula. Another excellent Odonata resource is Dragonflies and Damselflies of the East by Dennis Paulson. (Photo: Mating darners (fast flying, large dragonflies), male above female)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Shadow Darners Laying Eggs
The dragonfly family Aeshnidae consists of strong-flying dragonflies called darners, some of which are over three inches in length. The majority of darners reach the peak of their population in August and early September. Male Shadow Darners (Aeshna umbrosa) can be seen patrolling breeding sites a few feet over the water’s surface, searching for females and driving off competing males. Females can be observed repeatedly landing at the base of cattails, inserting their sharp-edged ovipositors and slicing open leaves, where they then deposit their eggs. If you look at the bottom third of cattails at this time of year, near the water’s surface, you will find tiny, tan, vertical slits where dragonfly egg-laying has taken place. (Photo: female Shadow Darner laying eggs)
Darners Laying Eggs
Females of different species of dragonfly have different techniques for laying their eggs. Most skimmers, cruisers and clubtails dip the tip of their abdomen to the surface of the water while hovering or flying, and release their eggs. Most darners, such as the Shadow Darner (Aeshna umbrosa) pictured, have a sharp-edged ovipositor with which they slit open a stem or leaf of a plant on or near the water. They then push their egg into the plant tissue exposed by the slit. Because they are stationary during this process, female darners are vulnerable to predation by fish and frogs at this time. A close look at the bottom third of cattail leaves this time of year will tell you whether or not darners are in the vicinity, as the slits they make are very apparent, appearing as thin, tan, 1/2″ vertical lines.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate”
button.
Dragonflies Laying Eggs
Never let it be said that Naturally Curious readers aren’t creative thinkers (see guesses on yesterday’s post) ! The vertical slits in the cattail leaves were made by female dragonflies that were in the process of laying their eggs. There are many different egg-laying strategies employed by dragonflies. Many females in the group of large, strong-flying dragonflies known as “darners” (such as the pictured Black-tipped Darner, Aeshna tuberculifera) use their lance-like ovipositors (see photo) to insert eggs into plants stems such as cattail, sphagnum moss, rotting wood or wet soil. However, most species of dragonflies possess non-functional ovipositors. The eggs of many of these species are washed off into water during flight as the female dips the tip of her abdomen into the lake, pond, river or stream.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Naturally Curious with Mary Holland 
What Other Naturally Curious People Are Saying