Blue Emperor

Fascinating facts about the Blue Emperor

• The blue emperor is the biggest dragonfly across most of Europe, including the UK, out-sized by only a few local species. It measures 73-82 mm in length, with an average of 78 mm and males growing larger than females, and its wingspan averages 104 mm. Although the magnificent emperor and the long-ovipositor golden-ringed dragonfly can exceed it in very limited areas, in the majority of Europe it remains the largest species present.
• The blue emperor's range has surged northward, making it a regular visitor to Scandinavia. Since the 1990s its distribution has expanded both northwards and to higher altitudes, with the first Scandinavian record in Denmark in 1994, followed by Sweden in 2002 and Scotland in 2004. Today it is a common sight in all three countries, a shift that researchers link to global warming and its status as one of the first odonata to move in that direction.
• Its mitochondrial DNA is the longest recorded for any dragonfly, measuring 16 087 base pairs. This length is only slightly shorter than the human mitogenome, which contains 16 569 base pairs, and considerably longer than that of its close relative Anax parthenope at 15 366 base pairs. The unusually large genome highlights the species' distinct genetic makeup among odonates.
• The blue emperor's aquatic larvae grow to about 46 mm, making them among the largest dragonfly nymphs. Their aggressive nature means they readily attack other small aquatic organisms, and this predatory behaviour can reshape the native species composition of the freshwater habitats they colonise. They develop in a range of water bodies, from large ponds to slow-moving rivers and dikes, provided the water contains abundant vegetation for shelter and hunting.
• Adult male blue emperors are fiercely territorial, defending their preferred stretch of water against rivals and rarely allowing close approach. They patrol the sky high above water surfaces, hunting butterflies, other odonata and even tadpoles while maintaining this dominance. Their characteristic flight often shows the abdomen hanging slightly downwards, a visual cue that signals their presence to both competitors and prey.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia

At a glance

About the Blue Emperor

As the Blue Emperor dragonfly dances through the sun-dappled waterside, its iridescent blue body glimmers like a shard of splintered sky, its delicate wings beating at a hypnotic rhythm that belies the fierce hunter within. With a fluid, almost ethereal movement, it patrols its kingdom, a mesmerizing fusion of power and elegance as it hawks for prey with an unerring precision. In its effortless mastery of the air, the Blue Emperor embodies the very essence of a summer's day, its beauty and vitality woven into the fabric of the natural world.

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