Our chunkiest dragonfly, the emperor is found in large ponds and lakes, as well as canals and occasionally moving bodies of water. They are commonly found in gardens. Males are pale blue with a greenish thorax, while females are green. Both have green-blue eyes and a black stripe running along the top of their body. They fly high to catch prey such as butterflies and smaller dragonflies, and may be seen eating them on the wing.
Flying from June to August, the female lays eggs in pond weed. Unlike other dragonfly species, where the male clasps on to the female while she lays, the female emperor lays her eggs alone. The nymphs spend up to two years in the pond, eating tadpoles and other aquatic larvae, before climbing up tall stems and metamorphosing into an adult.
How to help emperor dragonflies
Dig a pond! Emperors need large bodies of water to lay eggs in. And, while you may not appreciate the blanket weed in your garden, this is what emperor dragonflies lay their eggs in.
In the pond, dragonfly nymphs eat tadpoles and the larvae of other aquatic species so make sure the pond provides a habitat for other species. Grow low-growing plants around the edge to cascade around the edges, so frog and toad tadpoles can exit easily, and plant water forget-me-not and brooklime for newts, which lay their eggs in the leaves.
As adults they eat large insects such as butterflies and smaller dragonflies. Create good habitats for them so there’s plenty of food around, including areas of long grass and wildflowers.
It may seem strange to create habitats for the species that emperor dragonflies eat but that is all part of the food chain – without other species to eat, emperor dragonflies wouldn’t breed in your garden.
Lastly, plant emergent plants in the pond, which the dragonflies will use to climb out of the water to complete their metamorphosis. Good plants to grow include flowering rush, purple loosestrife and water iris.
