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)
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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)
The Common Green Darner, Anax junius, is one of our largest dragonflies, measuring three inches long, with a four-inch wingspread. It is strikingly colored, with a green thorax and a bright blue (male) or reddish (female) abdomen. As if that weren’t enough to set this dragonfly apart, it is also migratory. Common Green Darners migrate south from August to November, stopping over (like migrating birds) occasionally along the way, resuming flight after resting and refueling. Thanks to radio telemetry, we now know that over a two-month migration, Common Green Darners, each weighing about one gram, can migrate over 400 miles. (Photograph is of a Common Green Darner perched on Bottle Gentian.)