Like all moths of the Sesiidae family, the Bembex clearwing resembles a hymenopteran (wasp) both in its appearance and flight.

However, apiformis has yellow 'epaulettes' on the "shoulders" directly above the wing bases; Sesia bembeciformis is dark coloured at this point except for the yellow neck ring.bembeciformis is also smaller and has a black head.

It resembles a big hornet (Vespa crabro) really well - an instance of mimicry.

The moths appear in June, July and August, they are then found resting on the trunks of willows.

The species has a hidden way of life, and the imago lives only briefly,[citation needed] which makes it easily overlooked.