In contrast to Japan where dragonflies are revered, dragonfly symbolism in Europe takes a more sinister tone - evoking the devil horses, weighing scales, needles and snakes.
In European folklore, dragonflies became associated with the devil and horses. The connection between dragonflies and horses probably started because of the observation that dragonflies were often seen around horses that were kicking and stomping. The horses were trying to rid themselves of biting pests such as flies and mosquitos. The dragonflies were attracted to horses to eat those biting pests. The people observing the large dragonflies just assumed that it was the dragonfly that was doing the biting, not the virtually unseen flies and mosquitoes. Dragonflies became known as "horse stingers", particularly in England and the Netherlands. Other European legends mention a horse growing wings to become a dragonfly (referred to as golden horse, little horse or goddess horse).
An association with the devil and horses also exists in European folklore. Its genesis may be linked to a very common theme of "putting the devil on horseback". Dragonflies were known to hover around (and perhaps ride on) horses, and so the association may have begun. In 1240, the Mongols who attacked Europe were known as the devil's horsemen. Based on the bible book of Revelations, the persecuted Christians believed that the arrival of the four horsemen of the apocalypse would bring the end of the world through war, famine, plague and death. The term "devil horse" was particularly mentioned in folklore from Denmark, Germany, Spain, England, France and Romania.
The black horse of the apocalypse feeds into the folklore imagery linking dragonflies with weighing scales. The third Horseman riding a black horse represented famine. This Horseman carried a pair of balances or weighing scales, that were used to weigh out wheat and barley during a famine. There was widespread belief that the weighing scales could also be used to weigh down the souls of the people who had died from famine. Early Christians believed that souls of sinners weighed more that the souls of virtuous people, and that the devil wanted to take the sinners with heavy souls to hell. The weighing scales were used to assist him in his task.
In Scandinavia, dragonflies were referred to as the "Devil's steelyard" or a Roman weighing scale. The shape of a dragonfly was thought to be similar to the weighing scale. In Swedish folklore, the devil used dragonflies to weight people’s souls. It was believed that when a dragonfly flew around your head, it weighted your soul and a serious injury was in your future.
European folklore links dragonflies to needles that are used to pierce, cut and poke eyes and ears. In Sweden, dragonflies were known as "blind stingers" that could pick out your eyes and "troll spindles" that were used for both weaving and poking out the eyes of the enemy. In Norway and Germany, dragonflies were believed to have the ability of sewing your eyelids shut. Norwegian folklore had images of dragonflies poking holes in children's eardrums. In England, dragonflies or the "Devil's darning needles" would sew closed the mouths of bad children while they slept.
Last, but not least, there is an association between dragonflies and snakes. Celtic folklore features the dragonfly as the protector of poisonous snakes, or "Adder's Servant". The Celtic people believed that dragonflies would protect the lives of injured poisonous snakes by stitching their wounds.