The Lunar Hornet Moth (Sesia bembeciformis) is a day flyer and flies only in July. Its unusual life cycle begins when the adults emerge from pupae in willow trees in early July. The female attracts a mate by wafting a pheromone and after mating she lays her eggs on willow bark. The larvae chew their way into the wood and stay there growing for two years before emerging and the cycle is then complete.
The Lunar Hornet Moth looks, sounds and flies like a hornet or giant wasp. It is one of a group of clearwing moths which use Batesian mimicry to deter predators, that is they disguise themselves as something more dangerous and unpalatable to a potential predator.
Since 2020 a synthetic pheromone has been commercially available and reports of adult moths have increased dramatically. This is the third year in a row I have had a go with a lure and all these photos are of males attracted to a pheromone lure in the past week. (The female moth looks very similar but is larger.) Once the moths have been in the trap for a few minutes they calm down and are happy to sit on a willow trunk for a few minutes while they gather their thoughts before flying off.
The photos on or in the trap aren't much good so I had a go at flight shots which are tricky but a few came out OK. This one was taken in natural light and the shutter speed wasn't fast enough to freeze the wing movement.
These were taken with flash.
For comparison here are a couple of European Hornets (Vespa crabro), also from Gosforth Nature Reserve but a few years ago. They are brown rather than black but otherwise the moth's mimicry is pretty impressive.
Fascinating!
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