Six-spot Burnet

• It makes cyanide: it stores cyanogenic glycosides, which it obtains from its food plant and can also synthesise itself, and releases a droplet smelling of bitter almonds if it is squeezed.
• Its red and black colouring is a classic warning, and several harmless species mimic its appearance to take advantage of that protection.
• The female chooses a mate partly by how much cyanide the male transfers with his sperm, which she then passes on to the eggs.
• It manufactures cyanide. It synthesises cyanogenic glucosides and stores them in its body; when attacked it releases hydrogen cyanide, which makes it toxic to almost any predator.
• And it advertises the fact: its black wings with six bright red spots are a classic aposematic warning, and several harmless species mimic it.
• It can obtain the cyanide in two ways: by synthesising it itself or by sequestering it from the bird's-foot trefoil it eats. It is one of the few animals capable of both.
• The cyanide also plays a part in courtship: the male offers the female a nuptial gift loaded with these compounds, which she incorporates into her eggs to protect them.
• It flies by day, slowly and heavily, with no need to flee from anyone: its toxicity protects it better than speed would.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Flowery meadows, banks and grassy slopes of Europe

Sexual maturity

The male transfers cyanogenic glycosides to the female as a nuptial gift during copulation; these same substances are involved in attracting a mate

Gestation / incubation

It overwinters as a caterpillar, sometimes for two winters in a row; it pupates in early summer in a papery cocoon, elongated and tapering, yellowish white, attached to a grass stem in an exposed position

Litter / clutch size

Ovoid, glossy eggs, whitish or yellowish, darkening to grey before hatching; they are laid in groups on the underside of the leaves of the food plant

Sources consulted: Zagrobelny et al. (2007 y 2014), Insect Biochemistry and Molecular Biology · Butterfly Conservation · Ficha de especie de Zygaena filipendulae (Gianluca Doremi) · ScienceDirect (Hughes 1989) · Science Advances, How colonial animals evolve · Wikipedia, Zooid · First Nature, ficha Zygaena filipendulae · Monaco Nature Encyclopedia · Ficha de especie de Zygaena filipendulae · Bulgarialeps

Best time: Flies by day on hot, sunny days from June to August, in meadows, woodland clearings and coastal cliffs rich in grasses and flowers, up to 2,000 m in altitude; it feeds on knapweeds and scabious