Sesia bembeciformis

Sesia bembeciformis, the lunar hornet moth, is a moth of the family Sesiidae. It is found in Europe.

Illustration from John Curtis's British Entomology Volume 5, depicting Sesia apiformis and Sesia bembeciformis

Figs. 2 larvae before last moult 2a larvae after last moult

Sesia bembeciformis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Sesiidae
Genus:	Sesia
Species:	S. bembeciformis
Binomial name
Sesia bembeciformis (Hübner, 1806)
Synonyms
Sphinx bembeciformis Hübner, 1806 Sphinx crabroniformis Lewin, 1797 (nec [Denis & Schiffermüller], 1775, nec Fabricius, 1793, nec Laspeyres, 1801) Sphecia dasypodiformis Walker, 1856 Aegeria montelli Löfqvist, 1922 Sphecia bembeciformis var. orophila Zukowsky, 1929 Aegeria bembeciformis ab. incognita Strand, [1927] Sphecia bembeciformis f. fumosa Lempke, 1961

The wingspan is 32–42 mm. The length of the forewings is 15–19 mm.

Sesia bembeciformis is hardly distinguishable from its closest congener Sesia apiformis. 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. In general, females are considerably larger than males. 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. These include sal willow (Salix caprea), ash willow (Salix cinerea) and ear willow (Salix aurita). The eggs are laid on the bark. The larvae first gnaw between the bark and the wood, but later crawl further into the stem. Larva development takes 3 – 4 years. The species has a hidden way of life, and the imago lives only briefly, which makes it easily overlooked.