Female damselflies have features on the front segment of the thorax. Male and female dragonflies tend to wed in the air, sometimes with an audible impact. Damselflies become hitched together more quietly, often coming together on vegetation. The mating formation is called a wheel. From the side, damselfly pairs appear sort of heart-shaped.
Damselflies usually land to mate.
In species that land, you can often see the legs of the female wrapped around the abdomen of the male for strain relief and support during mating. The male may assist the female by moving or curling his abdomen. For some species, the mating time is very short, only a few seconds. For others, especially some of the damselflies, it can be up to several hours. Damage incurred from prior mating activity can allow some inter-specific activity.