The frozen still life of the winter damselfly, which flies away unscathed when the frost is over

The Dutch winter is fatal for most insects. Some species survive this chilly time by overwintering in dry places where frost just cannot reach. The brown winter damselfly (Sympecma fusca) is a notable exception. This common damselfly clings to protruding twigs and appears to be completely frozen during frost. A popular subject for photographers.

Winter damselflies, like other winter insects, avoid heavy frost damage to their cells by lowering the freezing point of their cell fluid and also sabotaging the freezing process itself. When fluid freezes in cells, the crystals damage their structure and integrity. By keeping the moisture content in the cells as low as possible, the concentration of dissolved substances increases. This lowers the freezing point. In addition, insects produce more glycerol, a sugar alcohol that acts as an antifreeze. Glycerol works by interfering with hydrogen bonds when water freezes. This prevents the formation of ice crystals.

Despite this, the apparently frozen animals are closer to death than life, but when the mercury rises a few degrees above freezing, they fly on unscathed.

But why does an adult winter damselfly brave the elements where other insects prefer to hibernate protected or as eggs?

According to one Czech study from 2012 this strategy offers a selective advantage in early spring. Where other dragonflies or predators are not yet active, the winter damselfly can fly around free of competition as soon as the thaw sets in. This gives them plenty of time to reproduce.

In addition to the brown winter damselfly, the rare northern winter damselfly is also found in the Netherlands (Sympecma paedisca) that are difficult to distinguish from each other. These are the only two European damselflies that spend the winter in the adult stage. The Weerribben-Wieden, the largest low peat area in Western Europe, is a true bastion of the northern winter damselfly. In contrast to the brown winter damselfly, the northern winter damselfly is more restricted to specific low-lying peat areas.

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