When fully developed, which may take two years, it pupates under the soil, undergoes metamorphosis, emerging a month later as a much larger winged insect.

[5] Euroleon nostras has a widespread distribution in Europe, and has been recorded from almost all European countries, its range extending from Spain through Germany to western Russia.

[6] It is an extremely rare insect in Britain, known only from the Minsmere area of the Suffolk coast and Holkham National Nature Reserve in Norfolk.

[8] Small arthropods that inadvertently enter the trap are unable to climb out because of the loose surface and are pounced on by the ant-lion larva, which then sucks out their body fluids before tossing out the dry husk.

After this, the female flies to the ground, tapping it with her abdomen to find a suitable spot, and inserting her ovipositor into the sand and laying an egg.