Moths of
Britain and Europe
6-spot Burnet
Zygaena filipendulae
LINNAEUS,
1758
Family -
ZYGAENIDAE
subfamily -
ZYGAENINAE
Tribe -
introduction
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habitats |
lifecycle |
adult behaviour
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6-spot Burnet
Zygaena filipendulae, Stansted Forest, England |
Introduction
The
Burnets and Foresters belong to the Zygaenidae - a family which in many
respects
appears to straddle the gap between butterflies and moths - they are brightly
coloured, fly in sunshine, and have clubbed antennae; but they rest with the
wings folded down, and they pupate in silk cocoons.
All butterflies and moths belong to
the order Lepidoptera. This is divided into
34 superfamilies, each with particular characteristics. Most of the 600000
species distributed across these superfamilies are nocturnal species,
and have traditionally been called moths. It just so happens that in among them
are 2 particular superfamilies - the Hesperioidea and Papilionoidea,
whose 17000 or so members are almost exclusively day-flying species. Due to
this aspect of their behaviour, and their generally brighter colours, they
became
unscientifically regarded as "different" - and got called butterflies.
One of the other superfamilies is
the Zygaenoidea. It is
divided into 13 families. Some of these, e.g. Dalceridae, Limacodidae &
Megalopygidae, are comprised of mostly nocturnal species - these are usually drab in
colour, and have feathered antennae. Others including Zygaenidae are
day-flying, brightly coloured, with unfeathered antennae that are swollen at the
tips like those of butterflies.
The Zygaenidae comprises of about
1000 species, found mainly in the tropics, but with about 40 representatives in
Europe and north Africa.
The moths generally have a metallic
blue or green sheen, and many of the species have prominent red spots on the
forewings, and red hindwings. These bright colours are a warning to predators
that they are poisonous - their bodies contain levels of hydrogen
cyanide that are lethal to small birds.
Zygaena
filipendulae is found throughout Europe. It is usually found in large
colonies, each comprising of at least several hundred adults.
Habitats
This species is found in grassy areas at altitudes between sea level and about
500m.
Lifecycle
The
flattened barrel-shaped eggs are laid in neat batches on leaves of the
foodplants.
The caterpillars hatch in September but enter hibernation
after a few days, re-awakening in April to resume feeding. When
fully grown they are yellowish-green, slightly hairy, and marked with rows of
conspicuous black spots along the back and sides. They feed on bird'sfoot
trefoil Lotus corniculatus, kidney vetch
Anthyllis vulneraria and other herbaceous
Leguminosae.
The pupa is formed within a wrinkled and shiny white or yellowish cocoon which
is usually spun high up on a grass stem.
When the moth emerges the pupa remains wedged in the exit hole as shown in
the photograph above.
Adult behaviour
After emergence the females
sit on their cocoons and emit pheromones to attract males. Within
a few minutes a male arrives, and copulation takes place on the
cocoon. I have often found copulated pairs at dusk, so it seems
likely that the pair remain joined overnight, and part at first
light next morning.
The moths beat
their wings rapidly but have a slow buzzing flight,
very
reminiscent of bees
except that the Burnet's flight is
completely silent.
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