It can be assumed, as with all dragonfly species, that the northern emerald is a highly skilled predator. It detects its prey mainly by sight, congregating quickly in areas where prey is abundant, such as at a termite nest or beehive. All dragonflies are opportunistic and generalised predators, with small flying insects being the primary component of their diet (7).
The flight period of the northern emerald is between mid-May and September (2). Throughout this period, the male defends a territory around the edges of its chosen water body (3). Copulation takes place when a female dragonfly enters this territory, when the ‘wheel’ position is adopted, with the male grasping the female’s head with the claw-like appendages at the base of the abdomen. Egg laying in all dragonfly species follows shortly after copulation (2), with the female northern emerald laying the eggs alone, placing the tip of the abdomen below the Sphagnum moss at the surface of the peat bog or swamp (3).
All dragonfly larvae have a ‘mask’, which is an extendable structure that has strong hooks to grip prey and is retracted back to the mouth to eat it (2) (7). The larvae of the northern emerald burrow into the Sphagnum moss (2), and emerge to metamorphose into the adult form after two years of development (3).